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Abstract
Expansins comprise an ancient group of cell wall proteins ubiquitous in land plants and their algal ancestors. During cell growth, they facilitate passive yielding of the wall's cellulose networks to turgor-generated tensile stresses, without evidence of enzymatic activity. Expansins are also implicated in fruit softening and other developmental processes and in adaptive responses to environmental stresses and pathogens. The major expansin families in plants include α-expansins (EXPAs), which act on cellulose-cellulose junctions, and β-expansins, which can act on xylans. EXPAs mediate acid growth, which contributes to wall enlargement by auxin and other growth agents. The genomes of diverse microbes, including many plant pathogens, also encode expansins designated expansin-like X. Expansins are proposed to disrupt noncovalent bonding between laterally aligned polysaccharides (notably cellulose), facilitating wall loosening for a variety of biological roles.
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Affiliation(s)
- Daniel J Cosgrove
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA;
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2
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Liao S, Xu Z, Fan X, Zhou Q, Liu X, Jiang C, Ma F, Wang Y, Wang T, Feng B. Identification and validation of two major QTL for grain number per spike on chromosomes 2B and 2D in bread wheat (Triticum aestivum L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:147. [PMID: 38834870 DOI: 10.1007/s00122-024-04652-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 05/16/2024] [Indexed: 06/06/2024]
Abstract
KEY MESSAGE Major QTL for grain number per spike were identified on chromosomes 2B and 2D. Haplotypes and candidate genes of QGns.cib-2B.1 were analyzed. Grain number per spike (GNS) is one of the main components of wheat yield. Genetic dissection of their regulatory factors is essential to improve the yield potential. In present study, a recombinant inbred line population comprising 180 lines developed from the cross between a high GNS line W7268 and a cultivar Chuanyu12 was employed to identify quantitative trait loci (QTL) associated with GNS across six environments. Two major QTL, QGns.cib-2B.1 and QGns.cib-2D.1, were detected in at least four environments with the phenotypic variations of 12.99-27.07% and 8.50-13.79%, respectively. And significant interactions were observed between the two major QTL. In addition, QGns.cib-2B.1 is a QTL cluster for GNS, grain number per spikelet and fertile tiller number, and they were validated in different genetic backgrounds using Kompetitive Allele Specific PCR (KASP) markers. QGns.cib-2B.1 showed pleotropic effects on other yield-related traits including plant height, spike length, and spikelet number per spike, but did not significantly affect thousand grain weight which suggested that it might be potentially applicable in breeding program. Comparison analysis suggested that QGns.cib-2B.1 might be a novel QTL. Furthermore, haplotype analysis of QGns.cib-2B.1 indicated that it is a hot spot of artificial selection during wheat improvement. Based on the expression patterns, gene annotation, orthologs analysis and sequence variations, the candidate genes of QGns.cib-2B.1 were predicted. Collectively, the major QTL and KASP markers reported here provided a wealth of information for the genetic basis of GNS and grain yield improvement.
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Affiliation(s)
- Simin Liao
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhibin Xu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Xiaoli Fan
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Qiang Zhou
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Xiaofeng Liu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cheng Jiang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fang Ma
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanlin Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tao Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
- The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Bo Feng
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
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3
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Chebli Y, Geitmann A. Pectate lyase-like lubricates the male gametophyte's path toward its mating partner. PLANT PHYSIOLOGY 2023; 194:124-136. [PMID: 37658849 DOI: 10.1093/plphys/kiad481] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 07/10/2023] [Accepted: 08/12/2023] [Indexed: 09/05/2023]
Abstract
The pollen tube is an extension of the male gametophyte in plants and mediates sexual reproduction by delivering the sperm cells to the female gametophyte. To accomplish this task, the elongating pollen tube must break through the thick wall of the pollen grain and penetrate multiple pistillar tissues. Both processes require the loosening of cell wall material-that of the pollen intine and that of the apoplast of the transmitting tract. The enzymatic toolbox for these cell wall modifying processes employed by the invading male gametophyte is elusive. We investigated the role of the pectin-digesting pectate lyase-like (PLL) by combining mutant analysis with microscopy observations, fluorescence recovery after photo-bleaching experiments, and immuno-detection. We show that in Arabidopsis (Arabidopsis thaliana), PLLs are required for intine loosening during the first steps of pollen tube germination. We provide evidence that during pollen tube elongation, PLLs are released by the pollen tube into the extracellular space, suggesting that they may be employed to soften the apoplast of the transmitting tissue. The synergistic enzymatic action of PLLs in the pollen grain, the pollen tube, and the transmitting track contribute to an effective fertilization process.
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Affiliation(s)
- Youssef Chebli
- Department of Plant Science, McGill University, Ste-Anne-de-Bellevue, Québec H9X 3V9, Canada
- ECP3-Multi-Scale Imaging Facility, McGill University, Ste-Anne-de-Bellevue, Québec H9X 3V9, Canada
| | - Anja Geitmann
- Department of Plant Science, McGill University, Ste-Anne-de-Bellevue, Québec H9X 3V9, Canada
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4
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Yuan X, Xu J, Yu J, Zhu D, Li H, Zhao Q. The NAC transcription factor ZmNAC132 regulates leaf senescence and male fertility in maize. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023:111774. [PMID: 37331633 DOI: 10.1016/j.plantsci.2023.111774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/20/2023]
Abstract
Leaf senescence is an integral step in the final stages of plant development, as nutrient remobilization from leaves to sink organs is accomplished during this process. NACs compose a large superfamily of plant-specific TFs involved in multiple plant development processes. Here, we identified a maize NAC TF, ZmNAC132, involved in leaf senescence and male fertility. ZmNAC132 expression was tightly linked to leaf senescence in an age-dependent manner. Knockout of ZmNAC132 led to delays in chlorophyll degradation and leaf senescence, whereas overexpression of ZmNAC132 had the opposite effects. ZmNAC132 could bind to and transactivate the promoter of ZmNYE1, a major chlorophyll catabolic gene, to accelerate chlorophyll degradation during leaf senescence. Moreover, ZmNAC132 affected male fertility through the upregulation of ZmEXPB1, an expansin-encoding gene associated with sexual reproduction and other related genes. Together, the results show that ZmNAC132 participates in the regulation of leaf senescence and male fertility through the targeting of different downstream genes in maize.
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Affiliation(s)
- Xiaohong Yuan
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Jianghai Xu
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Jingjuan Yu
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Dengyun Zhu
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Hongjie Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Qian Zhao
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China.
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5
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Geng X, Wang X, Wang J, Yang X, Zhang L, Song X. TaEXPB5 functions as a gene related to pollen development in thermo-sensitive male-sterility wheat with Aegilops kotschyi cytoplasm. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 323:111377. [PMID: 35820549 DOI: 10.1016/j.plantsci.2022.111377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/04/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
The thermo-sensitive cytoplasmic male-sterility line with Aegilops kotschyi cytoplasm (K-TCMS) is completely male sterile under low temperature (< 18 ℃) during Zadoks growth stages 45-52, whereas its fertility can be restored under hot temperature (≥ 20 ℃). The K-TCMS line may facilitate hybrid breeding and hybrid wheat production. Therefore, to elucidate the molecular mechanisms of its male sterility/fertility conversion, we conducted the association analysis of proteins and transcript expression to screen fertility related genes using RNA-seq, iTRAQ, and PRM-based assay. A gene encoding expansin protein in wheat, TaEXPB5, was isolated in K-TCMS line KTM3315A, which upregulated expression in the fertility anthers. Subcellular localization analysis suggested that TaEXPB5 protein localized to nucleus and cell wall. The silencing of TaEXPB5 displayed pollen abortion and the declination of fertility. Further, cytological investigation indicated that the silencing of TaEXPB5 induced the early degradation of tapetum and abnormal development of pollen wall. These results implied that TaEXPB5 may be essential for anther or pollen development and male fertility of KTM3315A. These findings provide a novel insight into molecular mechanism of fertility conversion for thermo-sensitive cytoplasmic male-sterility wheat, and contribute to the molecular breeding of hybrid wheat in the future.
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Affiliation(s)
- Xingxia Geng
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Xiaoxia Wang
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Jingchen Wang
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Xuetong Yang
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Lingli Zhang
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Xiyue Song
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China.
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6
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Jiao Z, Yin L, Zhang Q, Xu W, Jia Y, Xia K, Zhang M. The putative obtusifoliol 14α-demethylase OsCYP51H3 affects multiple aspects of rice growth and development. PHYSIOLOGIA PLANTARUM 2022; 174:e13764. [PMID: 35975452 DOI: 10.1111/ppl.13764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/25/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
Some members of the CYP51G subfamily has been shown to be obtusifoliol 14α-demethylase, key enzyme of the sterol and brassinosteroid (BR) biosynthesis, which mediate plant development and response to stresses. However, little is known about the functions of CYP51H subfamily in rice. Here, OsCYP51H3, an ortholog of rice OsCYP51G1 was identified. Compared with wild type, the mutants oscyp51H3 and OsCYP51H3-RNAi showed dwarf phenotype, late flowering, erected leaves, lower seed-setting rate, and smaller and shorter seeds. In contrast, the phenotypic changes of OsCYP51H3-OE plants are not obvious. Metabolomic analysis of oscyp51H3 mutant indicated that OsCYP51H3 may also encode an obtusifoliol 14α-demethylase involved in phytosterol and BR biosynthesis, but possibly not that of triterpenes. The RNA-seq results showed that OsCYP51H3 may affect the expression of a lot of genes related to rice development. These findings showed that OsCYP51H3 codes for a putative obtusifoliol 14α-demethylase involved in phytosterol and BR biosynthesis, and mediates rice development.
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Affiliation(s)
- Zhengli Jiao
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Lijuan Yin
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qiming Zhang
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Weijuan Xu
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yongxia Jia
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Kuaifei Xia
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Mingyong Zhang
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
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7
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Samalova M, Gahurova E, Hejatko J. Expansin-mediated developmental and adaptive responses: A matter of cell wall biomechanics? QUANTITATIVE PLANT BIOLOGY 2022; 3:e11. [PMID: 37077967 PMCID: PMC10095946 DOI: 10.1017/qpb.2022.6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 03/16/2022] [Accepted: 03/29/2022] [Indexed: 05/03/2023]
Abstract
Biomechanical properties of the cell wall (CW) are important for many developmental and adaptive responses in plants. Expansins were shown to mediate pH-dependent CW enlargement via a process called CW loosening. Here, we provide a brief overview of expansin occurrence in plant and non-plant species, their structure and mode of action including the role of hormone-regulated CW acidification in the control of expansin activity. We depict the historical as well as recent CW models, discuss the role of expansins in the CW biomechanics and address the developmental importance of expansin-regulated CW loosening in cell elongation and new primordia formation. We summarise the data published so far on the role of expansins in the abiotic stress response as well as the rather scarce evidence and hypotheses on the possible mechanisms underlying expansin-mediated abiotic stress resistance. Finally, we wrap it up by highlighting possible future directions in expansin research.
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Affiliation(s)
- Marketa Samalova
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Evelina Gahurova
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biotechnological Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jan Hejatko
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biotechnological Research, Faculty of Science, Masaryk University, Brno, Czech Republic
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8
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de Sandozequi A, Salazar-Cortés JJ, Tapia-Vázquez I, Martínez-Anaya C. Prevalent association with the bacterial cell envelope of prokaryotic expansins revealed by bioinformatics analysis. Protein Sci 2022; 31:e4315. [PMID: 35481628 PMCID: PMC9045087 DOI: 10.1002/pro.4315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 11/10/2022]
Abstract
Expansins are a group of proteins from diverse organisms from bacteria to plants. Although expansins show structural conservation, their biological roles seem to differ among kingdoms. In plants, these proteins remodel the cell wall during plant growth and other processes. Contrarily, determination of bacterial expansin activity has proven difficult, although genetic evidence of bacterial mutants indicates that expansins participate in bacteria-plant interactions. Nevertheless, a large proportion of expansin genes are found in the genomes of free-living bacteria, suggesting roles that are independent of the interaction with living plants. Here, we analyzed all available sequences of prokaryotic expansins for correlations between surface electric charge, extra protein modules, and sequence motifs for association with the bacteria exterior after export. Additionally, information on the fate of protein after translocation across the membrane also points to bacterial cell association of expansins through six different mechanisms, such as attachment of a lipid molecule for membrane anchoring in diderm species or covalent linking to the peptidoglycan layer in monoderms such as the Bacilliales. Our results have implications for expansin function in the context of bacteria-plant interactions and also for free-living species in which expansins might affect cell-cell or cell-substrate interaction properties and indicate the need to re-examine the roles currently considered for these proteins.
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Affiliation(s)
- Andrés de Sandozequi
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
| | - Juan José Salazar-Cortés
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
| | - Irán Tapia-Vázquez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
| | - Claudia Martínez-Anaya
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, Mexico
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9
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Cheung AY, Cosgrove DJ, Hara-Nishimura I, Jürgens G, Lloyd C, Robinson DG, Staehelin LA, Weijers D. A rich and bountiful harvest: Key discoveries in plant cell biology. THE PLANT CELL 2022; 34:53-71. [PMID: 34524464 PMCID: PMC8773953 DOI: 10.1093/plcell/koab234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/01/2021] [Indexed: 05/13/2023]
Abstract
The field of plant cell biology has a rich history of discovery, going back to Robert Hooke's discovery of cells themselves. The development of microscopes and preparation techniques has allowed for the visualization of subcellular structures, and the use of protein biochemistry, genetics, and molecular biology has enabled the identification of proteins and mechanisms that regulate key cellular processes. In this review, seven senior plant cell biologists reflect on the development of this research field in the past decades, including the foundational contributions that their teams have made to our rich, current insights into cell biology. Topics covered include signaling and cell morphogenesis, membrane trafficking, cytokinesis, cytoskeletal regulation, and cell wall biology. In addition, these scientists illustrate the pathways to discovery in this exciting research field.
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Affiliation(s)
- Alice Y Cheung
- Department of Biochemistry and Molecular Biology, Molecular Cell Biology Program, Plant Biology Program, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Daniel J Cosgrove
- Department of Biology, Penn State University, University Park, Pennsylvania 16802, USA
| | | | - Gerd Jürgens
- ZMBP-Developmental Genetics, University of Tuebingen, Tuebingen 72076, Germany
| | - Clive Lloyd
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - David G Robinson
- Centre for Organismal Studies, University of Heidelberg, Heidelberg D-69120, Germany
| | - L Andrew Staehelin
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347, USA
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Wageningen 6708WE, the Netherlands
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10
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Sudharson S, Kalic T, Hafner C, Breiteneder H. Newly defined allergens in the WHO/IUIS Allergen Nomenclature Database during 01/2019-03/2021. Allergy 2021; 76:3359-3373. [PMID: 34310736 PMCID: PMC9290965 DOI: 10.1111/all.15021] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 01/03/2023]
Abstract
The WHO/IUIS Allergen Nomenclature Database (http://allergen.org) provides up‐to‐date expert‐reviewed data on newly discovered allergens and their unambiguous nomenclature to allergen researchers worldwide. This review discusses the 106 allergens that were accepted by the Allergen Nomenclature Sub‐Committee between 01/2019 and 03/2021. Information about protein family membership, patient cohorts, and assays used for allergen characterization is summarized. A first allergenic fungal triosephosphate isomerase, Asp t 36, was discovered in Aspergillus terreus. Plant allergens contained 1 contact, 38 respiratory, and 16 food allergens. Can s 4 from Indian hemp was identified as the first allergenic oxygen‐evolving enhancer protein 2 and Cic a 1 from chickpeas as the first allergenic group 4 late embryogenesis abundant protein. Among the animal allergens were 19 respiratory, 28 food, and 3 venom allergens. Important discoveries include Rap v 2, an allergenic paramyosin in molluscs, and Sal s 4 and Pan h 4, allergenic fish tropomyosins. Paramyosins and tropomyosins were previously known mainly as arthropod allergens. Collagens from barramundi, Lat c 6, and salmon, Sal s 6, were the first members from the collagen superfamily added to the database. In summary, the addition of 106 new allergens to the previously listed 930 allergens reflects the continuous linear growth of the allergen database. In addition, 17 newly described allergen sources were included.
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Affiliation(s)
- Srinidhi Sudharson
- Department of Dermatology University Hospital St. Poelten Karl Landsteiner University of Health Sciences St. Poelten Austria
- Division of Medical Biotechnology Department of Pathophysiology and Allergy Research Center of Pathophysiology, Infectiology and Immunology Medical University of Vienna Vienna Austria
| | - Tanja Kalic
- Department of Dermatology University Hospital St. Poelten Karl Landsteiner University of Health Sciences St. Poelten Austria
- Division of Medical Biotechnology Department of Pathophysiology and Allergy Research Center of Pathophysiology, Infectiology and Immunology Medical University of Vienna Vienna Austria
| | - Christine Hafner
- Department of Dermatology University Hospital St. Poelten Karl Landsteiner University of Health Sciences St. Poelten Austria
| | - Heimo Breiteneder
- Division of Medical Biotechnology Department of Pathophysiology and Allergy Research Center of Pathophysiology, Infectiology and Immunology Medical University of Vienna Vienna Austria
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Abstract
Pollen-pistil interactions serve as important prezygotic reproductive barriers that play a critical role in mate selection in plants. Here, we highlight recent progress toward understanding the molecular basis of pollen-pistil interactions as reproductive isolating barriers. These barriers can be active systems of pollen rejection, or they can result from a mismatch of required male and female factors. In some cases, the barriers are mechanistically linked to self-incompatibility systems, while others represent completely independent processes. Pollen-pistil reproductive barriers can act as soon as pollen is deposited on a stigma, where penetration of heterospecific pollen tubes is blocked by the stigma papillae. As pollen tubes extend, the female transmitting tissue can selectively limit growth by producing cell wall-modifying enzymes and cytotoxins that interact with the growing pollen tube. At ovules, differential pollen tube attraction and inhibition of sperm cell release can act as barriers to heterospecific pollen tubes.
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Affiliation(s)
- Amanda K Broz
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523-1878, USA; ,
| | - Patricia A Bedinger
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523-1878, USA; ,
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12
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Jia XL, Xue JS, Zhang F, Yao C, Shen SY, Sui CX, Peng YJ, Xu QL, Feng YF, Hu WJ, Xu P, Yang ZN. A dye combination for the staining of pollen coat and pollen wall. PLANT REPRODUCTION 2021; 34:91-101. [PMID: 33903950 DOI: 10.1007/s00497-021-00412-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
The pollen coat, which forms on the pollen surface, consists of a lipid-protein matrix. It protects pollen from desiccation and is involved in adhesion, pollen-stigma recognition, and pollen hydration during interactions with the stigma. The classical methods used for pollen coat observation are scanning and transmission electron microscopy. In this work, we screened a collection of fluorescence dyes and identified two fluorescent brighteners FB-52 and FB-184. When they were used together with the exine-specific dye, Basic fuchsin, the pollen coat and the exine structures could be clearly visualized in the pollen of Brassica napus. This co-staining method was applied successfully in staining pollen from Fraxinus chinensis, Calystegia hederacea, and Petunia hybrida. Using this method, small pollen coat-containing cavities were detected in the outer pollen wall layer of Oryza sativa and Zea mays. We further showed these dyes are compatible with fluorescent protein markers. In the Arabidopsis thaliana transgenic line of GFP-tagged pollen coat protein GRP19, GRP19-GFP was observed to form particles at the periphery of pollen coat. This simple staining method is expected to be widely used for the studies of the palynology as well as the pollen-stigma interaction.
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Affiliation(s)
- Xin-Lei Jia
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Jing-Shi Xue
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Fang Zhang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Chi Yao
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Shi-Yi Shen
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Chang-Xu Sui
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Yu-Jia Peng
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Qin-Lin Xu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Yi-Feng Feng
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Wen-Jing Hu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Ping Xu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China.
| | - Zhong-Nan Yang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China.
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13
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González-Ruiz A, López-Matas MÁ, Moya R, Carnés J. Immunoinformatic epitope prediction to select monoclonal antibodies for Phl p 1 quantification. Mol Immunol 2021; 136:1-7. [PMID: 34051631 DOI: 10.1016/j.molimm.2021.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/22/2021] [Accepted: 05/13/2021] [Indexed: 11/15/2022]
Abstract
BACKGROUND Allergen quantification has become a relevant parameter for allergen extract characterization and to guarantee the consistency of the manufacturing process at allergen immunotherapy. The aim of this study was to develop and validate a method to quantify the major allergen Phl p 1 based on a prediction of the antigenic regions by immunoinformatic strategies. METHODS Phl p 1 was purified from a Phleum pratense native extract by chromatographic methods. Immunoinformatic tools were used to predict B-cell epitopes. In silico predictions were verified by mapping linear epitopes with a peptide library and used to select the appropriate regions for producing the mAbs to develop an ELISA method, which was validated. Phl p 1 was quantified in 24 batches of P. pratense extracts. RESULTS Phl p 1 was purified with 95 % purity and completely functional. Eight B-cell epitopes in each of the two Phl p 1 isoforms were predicted. Two of the predicted B-cell epitopes overlapped with the experimentally determined peptides recognized by two mAbs selected for development of the kit. The quantification method demonstrated to be specific to Phl p 1, linear, accurate and precise in the range from 7.7 to 123.3 μg/mg. Mean Phl p 1 content was 28.95 μg of allergen/mg of lyophilized native extract and 44.23 μg of allergen/mg of lyophilized depigmented extract. CONCLUSIONS An ELISA method for measuring Phl p 1 in P. pratense extracts was developed and validated by producing the appropriate mAbs against epitopes selected by immunoinformatic tools.
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Affiliation(s)
| | | | - Raquel Moya
- R&D Allergy & Immunology Unit, LETI Pharma S.L.U, Madrid, Spain
| | - Jerónimo Carnés
- R&D Allergy & Immunology Unit, LETI Pharma S.L.U, Madrid, Spain.
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14
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Affiliation(s)
- Daniel J Cosgrove
- Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
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15
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Two Expansin Genes, AtEXPA4 and AtEXPB5, Are Redundantly Required for Pollen Tube Growth and AtEXPA4 Is Involved in Primary Root Elongation in Arabidopsis thaliana. Genes (Basel) 2021; 12:genes12020249. [PMID: 33578704 PMCID: PMC7916401 DOI: 10.3390/genes12020249] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/30/2021] [Accepted: 02/05/2021] [Indexed: 12/12/2022] Open
Abstract
The growth of plant cells is inseparable from relaxation and expansion of cell walls. Expansins are a class of cell wall binding proteins, which play important roles in the relaxation of cell walls. Although there are many members in expansin gene family, the functions of most expansin genes in plant growth and development are still poorly understood. In this study, the functions of two expansin genes, AtEXPA4 and AtEXPB5 were characterized in Arabidopsis thaliana. AtEXPA4 and AtEXPB5 displayed consistent expression patterns in mature pollen grains and pollen tubes, but AtEXPA4 also showed a high expression level in primary roots. Two single mutants, atexpa4 and atexpb5, showed normal reproductive development, whereas atexpa4atexpb5 double mutant was defective in pollen tube growth. Moreover, AtEXPA4 overexpression enhanced primary root elongation, on the contrary, knocking out AtEXPA4 made the growth of primary root slower. Our results indicated that AtEXPA4 and AtEXPB5 were redundantly involved in pollen tube growth and AtEXPA4 was required for primary root elongation.
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16
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Lohani N, Singh MB, Bhalla PL. RNA-Seq Highlights Molecular Events Associated With Impaired Pollen-Pistil Interactions Following Short-Term Heat Stress in Brassica napus. FRONTIERS IN PLANT SCIENCE 2021; 11:622748. [PMID: 33584763 PMCID: PMC7872974 DOI: 10.3389/fpls.2020.622748] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/08/2020] [Indexed: 05/09/2023]
Abstract
The global climate change is leading to increased frequency of heatwaves with crops getting exposed to extreme temperature events. Such temperature spikes during the reproductive stage of plant development can harm crop fertility and productivity. Here we report the response of short-term heat stress events on the pollen and pistil tissues in a commercially grown cultivar of Brassica napus. Our data reveals that short-term temperature spikes not only affect pollen fitness but also impair the ability of the pistil to support pollen germination and pollen tube growth and that the heat stress sensitivity of pistil can have severe consequences for seed set and yield. Comparative transcriptome profiling of non-stressed and heat-stressed (40°C for 30 min) pollen and pistil (stigma + style) highlighted the underlying cellular mechanisms involved in heat stress response in these reproductive tissues. In pollen, cell wall organization and cellular transport-related genes possibly regulate pollen fitness under heat stress while the heat stress-induced repression of transcription factor encoding transcripts is a feature of the pistil response. Overall, high temperature altered the expression of genes involved in protein processing, regulation of transcription, pollen-pistil interactions, and misregulation of cellular organization, transport, and metabolism. Our results show that short episodes of high-temperature exposure in B. napus modulate key regulatory pathways disrupted reproductive processes, ultimately translating to yield loss. Further investigations on the genes and networks identified in the present study pave a way toward genetic improvement of the thermotolerance and reproductive performance of B. napus varieties.
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Affiliation(s)
| | | | - Prem L. Bhalla
- Plant Molecular Biology and Biotechnology Laboratory, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
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17
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Li Y, Niu L, Wu X, Faleri C, Tai F, Zhang M, Liu H, Wang W, Cai G. Genome-Wide Identification and Comparison of Cysteine Proteases in the Pollen Coat and Other Tissues in Maize. FRONTIERS IN PLANT SCIENCE 2021; 12:709534. [PMID: 34630461 PMCID: PMC8494779 DOI: 10.3389/fpls.2021.709534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/24/2021] [Indexed: 05/07/2023]
Abstract
Cysteine proteases, belonging to the C1-papain family, play a major role in plant growth and development, senescence, and immunity. There is evidence to suggest that pollen cysteine protease (CP) (ZmCP03) is involved in regulating the anther development and pollen formation in maize. However, there is no report on the genome-wide identification and comparison of CPs in the pollen coat and other tissues in maize. In this study, a total of 38 homologous genes of ZmCP03 in maize were identified. Subsequently, protein motifs, conserved domains, gene structures, and duplication patterns of 39 CPs are analyzed to explore their evolutionary relationship and potential functions. The cis-elements were identified in the upstream sequence of 39 CPs, especially those that are related to regulating growth and development and responding to environmental stresses and hormones. The expression patterns of these genes displayed remarked difference at a tissue or organ level in maize based on the available transcriptome data in the public database. Quantitative reverse transcription PCR (RT-qPCR) analysis showed that ZmCP03 was preferably expressed at a high level in maize pollen. Analyses by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot, immunofluorescence and immunogold electron microscopy all validated the cellular localization of ZmCP03 in both the pollen coat and pollen cytoplasm. In addition, 142 CP genes from Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa) and cotton (Gossypium hirsutum), together with 39 maize CPs, were retrieved to analyze their evolution by comparing with orthologous genes. The results suggested that ZmCP03 was relatively conservative and stable during evolution. This study may provide a referential evidence on the function of ZmCP03 in pollen development and germination in maize.
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Affiliation(s)
- Yanhua Li
- National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Liangjie Niu
- National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Xiaolin Wu
- National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Claudia Faleri
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Fuju Tai
- National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou, China
- *Correspondence: Fuju Tai
| | - Man Zhang
- National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Hui Liu
- National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Wei Wang
- National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou, China
- Wei Wang
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, Siena, Italy
- Giampiero Cai
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18
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Mayorga-Gómez A, Nambeesan SU. Temporal expression patterns of fruit-specific α- EXPANSINS during cell expansion in bell pepper (Capsicum annuum L.). BMC PLANT BIOLOGY 2020; 20:241. [PMID: 32466743 PMCID: PMC7254744 DOI: 10.1186/s12870-020-02452-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Expansins (EXPs) facilitate non-enzymatic cell wall loosening during several phases of plant growth and development including fruit growth, internode expansion, pollen tube growth, leaf and root development, and during abiotic stress responses. In this study, the spatial and temporal expression patterns of C. annuum α- EXPANSIN (CaEXPA) genes were characterized. Additionally, fruit-specific CaEXPA expression was correlated with the rate of cell expansion during bell pepper fruit development. RESULTS Spatial expression patterns revealed that CaEXPA13 was up-regulated in vegetative tissues and flowers, with the most abundant expression in mature leaves. Expression of CaEXPA4 was associated with stems and roots. CaEXPA3 was expressed abundantly in flower at anthesis suggesting a role for CaEXPA3 in flower development. Temporal expression analysis revealed that 9 out of the 21 genes were highly expressed during fruit development. Of these, expression of six genes, CaEXPA5, CaEXPA7, CaEXPA12, CaEXPA14 CaEXPA17 and CaEXPA19 were abundant 7 to 21 days after anthesis (DAA), whereas CaEXPA6 was strongly expressed between 14 and 28 DAA. Further, this study revealed that fruit growth and cell expansion occur throughout bell pepper development until ripening, with highest rates of fruit growth and cell expansion occurring between 7 and 14 DAA. The expression of CaEXPA14 and CaEXPA19 positively correlated with the rate of cell expansion, suggesting their role in post-mitotic cell expansion-mediated growth of the bell pepper fruit. In this study, a ripening specific EXP transcript, CaEXPA9 was identified, suggesting its role in cell wall disassembly during ripening. CONCLUSIONS This is the first genome-wide study of CaEXPA expression during fruit growth and development. Identification of fruit-specific EXPAs suggest their importance in facilitating cell expansion during growth and cell wall loosening during ripening in bell pepper. These EXPA genes could be important targets for future manipulation of fruit size and ripening characteristics.
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Affiliation(s)
- Andrés Mayorga-Gómez
- Department of Horticulture, University of Georgia, 120 Carlton Street, Athens, GA, 30602, USA
| | - Savithri U Nambeesan
- Department of Horticulture, University of Georgia, 120 Carlton Street, Athens, GA, 30602, USA.
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19
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Liu W, Lyu T, Xu L, Hu Z, Xiong X, Liu T, Cao J. Complex Molecular Evolution and Expression of Expansin Gene Families in Three Basic Diploid Species of Brassica. Int J Mol Sci 2020; 21:ijms21103424. [PMID: 32408673 PMCID: PMC7279145 DOI: 10.3390/ijms21103424] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/07/2020] [Accepted: 05/11/2020] [Indexed: 12/12/2022] Open
Abstract
Expansins are a kind of structural proteins of the plant cell wall, and they enlarge cells by loosening the cell walls. Therefore, expansins are involved in many growth and development processes. The complete genomic sequences of Brassica rapa, Brassica oleracea and Brassica nigra provide effective platforms for researchers to study expansin genes, and can be compared with analogues in Arabidopsis thaliana. This study identified and characterized expansin families in B. rapa, B. oleracea, and B. nigra. Through the comparative analysis of phylogeny, gene structure, and physicochemical properties, the expansin families were divided into four subfamilies, and then their expansion patterns and evolution details were explored accordingly. Results showed that after the three species underwent independent evolution following their separation from A. thaliana, the expansin families in the three species had increased similarities but fewer divergences. By searching divergences of promoters and coding sequences, significant positive correlations were revealed among orthologs in A. thaliana and the three basic species. Subsequently, differential expressions indicated extensive functional divergences in the expansin families of the three species, especially in reproductive development. Hence, these results support the molecular evolution of basic Brassica species, potential functions of these genes, and genetic improvement of related crops.
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Affiliation(s)
- Weimiao Liu
- Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China; (W.L.); (T.L.); (L.X.); (Z.H.); (X.X.); (T.L.)
- Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou 310058, China
| | - Tianqi Lyu
- Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China; (W.L.); (T.L.); (L.X.); (Z.H.); (X.X.); (T.L.)
- Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou 310058, China
| | - Liai Xu
- Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China; (W.L.); (T.L.); (L.X.); (Z.H.); (X.X.); (T.L.)
- Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou 310058, China
| | - Ziwei Hu
- Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China; (W.L.); (T.L.); (L.X.); (Z.H.); (X.X.); (T.L.)
- Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou 310058, China
| | - Xingpeng Xiong
- Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China; (W.L.); (T.L.); (L.X.); (Z.H.); (X.X.); (T.L.)
- Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou 310058, China
| | - Tingting Liu
- Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China; (W.L.); (T.L.); (L.X.); (Z.H.); (X.X.); (T.L.)
- Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou 310058, China
| | - Jiashu Cao
- Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China; (W.L.); (T.L.); (L.X.); (Z.H.); (X.X.); (T.L.)
- Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou 310058, China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou 310058, China
- Correspondence: ; Tel.: +86-571-8898-2597
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20
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Narváez-Barragán DA, Tovar-Herrera OE, Torres M, Rodríguez M, Humphris S, Toth IK, Segovia L, Serrano M, Martínez-Anaya C. Expansin-like Exl1 from Pectobacterium is a virulence factor required for host infection, and induces a defence plant response involving ROS, and jasmonate, ethylene and salicylic acid signalling pathways in Arabidopsis thaliana. Sci Rep 2020; 10:7747. [PMID: 32385404 PMCID: PMC7210985 DOI: 10.1038/s41598-020-64529-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 04/17/2020] [Indexed: 01/09/2023] Open
Abstract
Expansins are encoded by some phytopathogenic bacteria and evidence indicates that they act as virulence factors for host infection. Here we analysed the expression of exl1 by Pectobacterium brasiliense and Pectobacterium atrosepticum. In both, exl1 gene appears to be under quorum sensing control, and protein Exl1 can be observed in culture medium and during plant infection. Expression of exl1 correlates with pathogen virulence, where symptoms are reduced in a Δexl1 mutant strain of P. atrosepticum. As well as Δexl1 exhibiting less maceration of potato plants, fewer bacteria are observed at distance from the inoculation site. However, bacteria infiltrated into the plant tissue are as virulent as the wild type, suggesting that this is due to alterations in the initial invasion of the tissue. Additionally, swarming from colonies grown on MacConkey soft agar was delayed in the mutant in comparison to the wild type. We found that Exl1 acts on the plant tissue, probably by remodelling of a cell wall component or altering the barrier properties of the cell wall inducing a plant defence response, which results in the production of ROS and the induction of marker genes of the JA, ET and SA signalling pathways in Arabidopsis thaliana. Exl1 inactive mutants fail to trigger such responses. This defence response is protective against Pectobacterium brasiliense and Botrytis cinerea in more than one plant species.
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Affiliation(s)
- Delia A Narváez-Barragán
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62210, Cuernavaca, Morelos, Mexico
| | - Omar E Tovar-Herrera
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62210, Cuernavaca, Morelos, Mexico
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Martha Torres
- Centro de Ciencias Genómicas. Universidad Nacional Autónoma de México, 62110, Cuernavaca, Morelos, Mexico
| | - Mabel Rodríguez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62210, Cuernavaca, Morelos, Mexico
| | - Sonia Humphris
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Ian K Toth
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Lorenzo Segovia
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62210, Cuernavaca, Morelos, Mexico
| | - Mario Serrano
- Centro de Ciencias Genómicas. Universidad Nacional Autónoma de México, 62110, Cuernavaca, Morelos, Mexico
| | - Claudia Martínez-Anaya
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62210, Cuernavaca, Morelos, Mexico.
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21
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Hepler NK, Bowman A, Carey RE, Cosgrove DJ. Expansin gene loss is a common occurrence during adaptation to an aquatic environment. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:666-680. [PMID: 31627246 DOI: 10.1111/tpj.14572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/24/2019] [Accepted: 10/07/2019] [Indexed: 05/15/2023]
Abstract
Expansins comprise a superfamily of plant cell wall loosening proteins that can be divided into four individual families (EXPA, EXPB, EXLA and EXLB). Aside from inferred roles in a variety of plant growth and developmental traits, little is known regarding the function of specific expansin clades, for which there are at least 16 in flowering plants (angiosperms); however, there is evidence to suggest that some expansins have cell-specific functions, in root hair and pollen tube development, for example. Recently, two duckweed genomes have been sequenced (Spirodela polyrhiza strains 7498 and 9509), revealing significantly reduced superfamily sizes. We hypothesized that there would be a correlation between expansin loss and morphological reductions seen among highly adapted aquatic species. In order to provide an answer to this question, we characterized the expansin superfamilies of the greater duckweed Spirodela, the marine eelgrass Zostera marina and the bladderwort Utricularia gibba. We discovered rampant expansin gene and clade loss among the three, including a complete absence of the EXLB family and EXPA-VII. The most convincing correlation between morphological reduction and expansin loss was seen for Utricularia and Spirodela, which both lack root hairs and the root hair expansin clade EXPA-X. Contrary to the pattern observed in other species, four Utricularia expansins failed to branch within any clade, suggesting that they may be the result of neofunctionalization. Last, an expansin clade previously discovered only in eudicots was identified in Spirodela, allowing us to conclude that the last common ancestor of monocots and eudicots contained a minimum of 17 expansins.
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Affiliation(s)
- Nathan K Hepler
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Alexa Bowman
- Program in Biochemistry and Molecular Biology, Lebanon Valley College, 101 N. College Ave., Annville, PA, 17003, USA
| | - Robert E Carey
- Department of Biology, Lebanon Valley College, 101 N. College Ave., Annville, PA, 17003, USA
| | - Daniel J Cosgrove
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA
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22
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Prior N, Little SA, Boyes I, Griffith P, Husby C, Pirone-Davies C, Stevenson DW, Tomlinson PB, von Aderkas P. Complex reproductive secretions occur in all extant gymnosperm lineages: a proteomic survey of gymnosperm pollination drops. PLANT REPRODUCTION 2019; 32:153-166. [PMID: 30430247 PMCID: PMC6500509 DOI: 10.1007/s00497-018-0348-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/09/2018] [Indexed: 05/27/2023]
Abstract
KEY MESSAGE Complex protein-containing reproductive secretions are a conserved trait amongst all extant gymnosperms; the pollination drops of most groups include carbohydrate-modifying enzymes and defence proteins. Pollination drops are aqueous secretions that receive pollen and transport it to the ovule interior in gymnosperms (Coniferales, Cycadales, Ginkgoales, Gnetales). Proteins are well established as components of pollination drops in conifers (Coniferales) and Ephedra spp. (Gnetales), but it is unknown whether proteins are also present in the pollination drops of cycads (Cycadales), Ginkgo (Ginkgoales), Gnetum (Gnetales), or in the pollination drops produced by sterile ovules occurring on pollen plants in the Gnetales. We used liquid chromatography-tandem mass spectrometry followed by database-derived protein identification to conduct proteomic surveys of pollination drops collected from: Ceratozamia hildae, Zamia furfuracea and Cycas rumphii (Cycadales); Ginkgo biloba (Ginkgoales); Gnetum gnemon and Welwitschia mirabilis, including pollination drops from both microsporangiate and ovulate plants (Gnetales). We identified proteins in all samples: C. hildae (61), Z. furfuracea (40), C. rumphii (9), G. biloba (57), G. gnemon ovulate (17) and sterile ovules from microsporangiate plants (25) and W. mirabilis fertile ovules (1) and sterile ovules from microsporangiate plants (138). Proteins involved in defence and carbohydrate modification occurred in the drops of most groups, indicating conserved functions for proteins in pollination drops. Our study demonstrates that all extant gymnosperm groups produce complex reproductive secretions containing proteins, an ancient trait that likely contributed to the evolutionary success of seed plants.
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Affiliation(s)
- Natalie Prior
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, Canada
| | - Stefan A Little
- Department of Environmental and Plant Biology, Ohio University, Athens, OH, USA
| | - Ian Boyes
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, Canada
| | - Patrick Griffith
- Montgomery Botanical Center, 11901 Old Cutler Road, Coral Gables, FL, USA
| | - Chad Husby
- Montgomery Botanical Center, 11901 Old Cutler Road, Coral Gables, FL, USA
| | - Cary Pirone-Davies
- The Arnold Arboretum of Harvard University, 125 Arborway, Boston, MA, USA
| | | | - P Barry Tomlinson
- Montgomery Botanical Center, 11901 Old Cutler Road, Coral Gables, FL, USA
| | - Patrick von Aderkas
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, Canada.
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23
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Hoopes GM, Hamilton JP, Wood JC, Esteban E, Pasha A, Vaillancourt B, Provart NJ, Buell CR. An updated gene atlas for maize reveals organ-specific and stress-induced genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:1154-1167. [PMID: 30537259 PMCID: PMC6850026 DOI: 10.1111/tpj.14184] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/19/2018] [Accepted: 11/22/2018] [Indexed: 05/09/2023]
Abstract
Maize (Zea mays L.), a model species for genetic studies, is one of the two most important crop species worldwide. The genome sequence of the reference genotype, B73, representative of the stiff stalk heterotic group was recently updated (AGPv4) using long-read sequencing and optical mapping technology. To facilitate the use of AGPv4 and to enable functional genomic studies and association of genotype with phenotype, we determined expression abundances for replicated mRNA-sequencing datasets from 79 tissues and five abiotic/biotic stress treatments revealing 36 207 expressed genes. Characterization of the B73 transcriptome across six organs revealed 4154 organ-specific and 7704 differentially expressed (DE) genes following stress treatment. Gene co-expression network analyses revealed 12 modules associated with distinct biological processes containing 13 590 genes providing a resource for further association of gene function based on co-expression patterns. Presence-absence variants (PAVs) previously identified using whole genome resequencing data from 61 additional inbred lines were enriched in organ-specific and stress-induced DE genes suggesting that PAVs may function in phenological variation and adaptation to environment. Relative to core genes conserved across the 62 profiled inbreds, PAVs have lower expression abundances which are correlated with their frequency of dispersion across inbreds and on average have significantly fewer co-expression network connections suggesting that a subset of PAVs may be on an evolutionary path to pseudogenization. To facilitate use by the community, we developed the Maize Genomics Resource website (maize.plantbiology.msu.edu) for viewing and data-mining these resources and deployed two new views on the maize electronic Fluorescent Pictograph Browser (bar.utoronto.ca/efp_maize).
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Affiliation(s)
| | - John P. Hamilton
- Department of Plant BiologyMichigan State UniversityEast LansingMI48824USA
- Department of Energy Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMI48824USA
| | - Joshua C. Wood
- Department of Plant BiologyMichigan State UniversityEast LansingMI48824USA
- Department of Energy Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMI48824USA
| | - Eddi Esteban
- Department of Cell and Systems Biology/Centre for the Analysis of Genome Evolution and FunctionUniversity of TorontoTorontoOntarioM5S 3B2Canada
| | - Asher Pasha
- Department of Cell and Systems Biology/Centre for the Analysis of Genome Evolution and FunctionUniversity of TorontoTorontoOntarioM5S 3B2Canada
| | - Brieanne Vaillancourt
- Department of Plant BiologyMichigan State UniversityEast LansingMI48824USA
- Department of Energy Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMI48824USA
| | - Nicholas J. Provart
- Department of Cell and Systems Biology/Centre for the Analysis of Genome Evolution and FunctionUniversity of TorontoTorontoOntarioM5S 3B2Canada
| | - C. Robin Buell
- Department of Plant BiologyMichigan State UniversityEast LansingMI48824USA
- Department of Energy Great Lakes Bioenergy Research CenterMichigan State UniversityEast LansingMI48824USA
- Plant Resilience InstituteMichigan State UniversityEast LansingMI48824USA
- Michigan State University AgBioResearchEast LansingMI48824USA
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24
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Molecular features of grass allergens and development of biotechnological approaches for allergy prevention. Biotechnol Adv 2017; 35:545-556. [PMID: 28535924 DOI: 10.1016/j.biotechadv.2017.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 04/28/2017] [Accepted: 05/19/2017] [Indexed: 12/11/2022]
Abstract
Allergic diseases are characterized by elevated allergen-specific IgE and excessive inflammatory cell responses. Among the reported plant allergens, grass pollen and grain allergens, derived from agriculturally important members of the Poaceae family such as rice, wheat and barley, are the most dominant and difficult to prevent. Although many allergen homologs have been predicted from species such as wheat and timothy grass, fundamental aspects such as the evolution and function of plant pollen allergens remain largely unclear. With the development of genetic engineering and genomics, more primary sequences, functions and structures of plant allergens have been uncovered, and molecular component-based allergen-specific immunotherapies are being developed. In this review, we aim to provide an update on (i) the distribution and importance of pollen and grain allergens of the Poaceae family, (ii) the origin and evolution, and functional aspects of plant pollen allergens, (iii) developments of allergen-specific immunotherapy for pollen allergy using biotechnology and (iv) development of less allergenic plants using gene engineering techniques. We also discuss future trends in revealing fundamental aspects of grass pollen allergens and possible biotechnological approaches to reduce the amount of pollen allergens in grasses.
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25
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Zhou LZ, Juranić M, Dresselhaus T. Germline Development and Fertilization Mechanisms in Maize. MOLECULAR PLANT 2017; 10:389-401. [PMID: 28267957 DOI: 10.1016/j.molp.2017.01.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 01/29/2017] [Accepted: 01/31/2017] [Indexed: 05/06/2023]
Abstract
Maize is the most important agricultural crop used for food, feed, and biofuel as well as a raw material for industrial products such as packaging material. To increase yield and to overcome hybridization barriers, studies of maize gamete development, the pollen tube journey, and fertilization mechanisms were initiated more than a century ago. In this review, we summarize and discuss our current understanding of the regulatory components for germline development including sporogenesis and gametogenesis, the progamic phase of pollen germination and pollen tube growth and guidance, as well as fertilization mechanisms consisting of pollen tube arrival and reception, sperm cell release, fusion with the female gametes, and egg cell activation. Mechanisms of asexual seed development are not considered here. While only a few molecular players involved in these processes have been described to date and the underlying mechanisms are far from being understood, maize now represents a spearhead of reproductive research for all grass species. Recent development of essentially improved transformation and gene-editing systems may boost research in this area in the near future.
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Affiliation(s)
- Liang-Zi Zhou
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Martina Juranić
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
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26
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Marowa P, Ding A, Kong Y. Expansins: roles in plant growth and potential applications in crop improvement. PLANT CELL REPORTS 2016; 35:949-65. [PMID: 26888755 PMCID: PMC4833835 DOI: 10.1007/s00299-016-1948-4] [Citation(s) in RCA: 246] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/02/2016] [Indexed: 05/18/2023]
Abstract
KEY MESSAGE Results from various expansin related studies have demonstrated that expansins present an opportunity to improve various crops in many different aspects ranging from yield and fruit ripening to improved stress tolerance. The recent advances in expansin studies were reviewed. Besides producing the strength that is needed by the plants, cell walls define cell shape, cell size and cell function. Expansins are cell wall proteins which consist of four sub families; α-expansin, β-expansin, expansin-like A and expansin-like B. These proteins mediate cell wall loosening and they are present in all plants and in some microbial organisms and other organisms like snails. Decades after their initial discovery in cucumber, it is now clear that these small proteins have diverse biological roles in plants. Through their ability to enable the local sliding of wall polymers by reducing adhesion between adjacent wall polysaccharides and the part they play in cell wall remodeling after cytokinesis, it is now clear that expansins are required in almost all plant physiological development aspects from germination to fruiting. This is shown by the various reports from different studies using various molecular biology approaches such as gene achieve these many roles through their non-enzymatic wall loosening ability. This paper reviews and summarizes some of the reported functions of expansins and outlines the potential uses of expansins in crop improvement programs.
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Affiliation(s)
- Prince Marowa
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, People's Republic of China
| | - Anming Ding
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, People's Republic of China
| | - Yingzhen Kong
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, People's Republic of China.
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27
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Alagna F, Cirilli M, Galla G, Carbone F, Daddiego L, Facella P, Lopez L, Colao C, Mariotti R, Cultrera N, Rossi M, Barcaccia G, Baldoni L, Muleo R, Perrotta G. Transcript Analysis and Regulative Events during Flower Development in Olive (Olea europaea L.). PLoS One 2016; 11:e0152943. [PMID: 27077738 PMCID: PMC4831748 DOI: 10.1371/journal.pone.0152943] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 03/20/2016] [Indexed: 02/04/2023] Open
Abstract
The identification and characterization of transcripts involved in flower organ development, plant reproduction and metabolism represent key steps in plant phenotypic and physiological pathways, and may generate high-quality transcript variants useful for the development of functional markers. This study was aimed at obtaining an extensive characterization of the olive flower transcripts, by providing sound information on the candidate MADS-box genes related to the ABC model of flower development and on the putative genetic and molecular determinants of ovary abortion and pollen-pistil interaction. The overall sequence data, obtained by pyrosequencing of four cDNA libraries from flowers at different developmental stages of three olive varieties with distinct reproductive features (Leccino, Frantoio and Dolce Agogia), included approximately 465,000 ESTs, which gave rise to more than 14,600 contigs and approximately 92,000 singletons. As many as 56,700 unigenes were successfully annotated and provided gene ontology insights into the structural organization and putative molecular function of sequenced transcripts and deduced proteins in the context of their corresponding biological processes. Differentially expressed genes with potential regulatory roles in biosynthetic pathways and metabolic networks during flower development were identified. The gene expression studies allowed us to select the candidate genes that play well-known molecular functions in a number of biosynthetic pathways and specific biological processes that affect olive reproduction. A sound understanding of gene functions and regulatory networks that characterize the olive flower is provided.
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Affiliation(s)
- Fiammetta Alagna
- Institute of Biosciences and Bioresources, National Research Council, Perugia, Italy
| | - Marco Cirilli
- Laboratory of Molecular Ecophysiology and Biotechnology of Woody Plants, Department of Agricultural and Forestry Science, University of Tuscia, Viterbo, Italy
| | - Giulio Galla
- Laboratory of Plant Genetics and Genomics, DAFNAE, University of Padova, Legnaro (PD), Italy
| | - Fabrizio Carbone
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, TRISAIA Research Center, Rotondella (MT), Italy
| | - Loretta Daddiego
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, TRISAIA Research Center, Rotondella (MT), Italy
| | - Paolo Facella
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, TRISAIA Research Center, Rotondella (MT), Italy
| | - Loredana Lopez
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, TRISAIA Research Center, Rotondella (MT), Italy
| | - Chiara Colao
- Laboratory of Molecular Ecophysiology and Biotechnology of Woody Plants, Department of Agricultural and Forestry Science, University of Tuscia, Viterbo, Italy
| | - Roberto Mariotti
- Institute of Biosciences and Bioresources, National Research Council, Perugia, Italy
| | - Nicolò Cultrera
- Institute of Biosciences and Bioresources, National Research Council, Perugia, Italy
| | - Martina Rossi
- Institute of Biosciences and Bioresources, National Research Council, Perugia, Italy
| | - Gianni Barcaccia
- Laboratory of Plant Genetics and Genomics, DAFNAE, University of Padova, Legnaro (PD), Italy
| | - Luciana Baldoni
- Institute of Biosciences and Bioresources, National Research Council, Perugia, Italy
- * E-mail: (RM); (LB)
| | - Rosario Muleo
- Laboratory of Molecular Ecophysiology and Biotechnology of Woody Plants, Department of Agricultural and Forestry Science, University of Tuscia, Viterbo, Italy
- * E-mail: (RM); (LB)
| | - Gaetano Perrotta
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, TRISAIA Research Center, Rotondella (MT), Italy
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28
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Rejón JD, Delalande F, Schaeffer-Reiss C, Alché JDD, Rodríguez-García MI, Van Dorsselaer A, Castro AJ. The Pollen Coat Proteome: At the Cutting Edge of Plant Reproduction. Proteomes 2016; 4:E5. [PMID: 28248215 PMCID: PMC5217362 DOI: 10.3390/proteomes4010005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/18/2016] [Accepted: 01/21/2016] [Indexed: 01/09/2023] Open
Abstract
The tapetum is a single layer of secretory cells which encloses the anther locule and sustains pollen development and maturation. Upon apoptosis, the remnants of the tapetal cells, consisting mostly of lipids and proteins, fill the pits of the sculpted exine to form the bulk of the pollen coat. This extracellular matrix forms an impermeable barrier that protects the male gametophyte from water loss and UV light. It also aids pollen adhesion and hydration and retains small signaling compounds involved in pollen-stigma communication. In this study, we have updated the list of the pollen coat's protein components and also discussed their functions in the context of sexual reproduction.
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Affiliation(s)
- Juan David Rejón
- Plant Reproductive Biology Laboratory, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008 Granada, Spain.
| | - François Delalande
- Bio-Organic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France.
- IPHC, Centre National de la Recherche Scientifique (CNRS), UMR7178, 67087 Strasbourg, France.
| | - Christine Schaeffer-Reiss
- Bio-Organic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France.
- IPHC, Centre National de la Recherche Scientifique (CNRS), UMR7178, 67087 Strasbourg, France.
| | - Juan de Dios Alché
- Plant Reproductive Biology Laboratory, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008 Granada, Spain.
| | - María Isabel Rodríguez-García
- Plant Reproductive Biology Laboratory, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008 Granada, Spain.
| | - Alain Van Dorsselaer
- Bio-Organic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France.
- IPHC, Centre National de la Recherche Scientifique (CNRS), UMR7178, 67087 Strasbourg, France.
| | - Antonio Jesús Castro
- Plant Reproductive Biology Laboratory, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008 Granada, Spain.
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29
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Abstract
The growing cell wall in plants has conflicting requirements to be strong enough to withstand the high tensile forces generated by cell turgor pressure while selectively yielding to those forces to induce wall stress relaxation, leading to water uptake and polymer movements underlying cell wall expansion. In this article, I review emerging concepts of plant primary cell wall structure, the nature of wall extensibility and the action of expansins, family-9 and -12 endoglucanases, family-16 xyloglucan endotransglycosylase/hydrolase (XTH), and pectin methylesterases, and offer a critical assessment of their wall-loosening activity.
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Affiliation(s)
- Daniel J Cosgrove
- Department of Biology, 208 Mueller Lab, Pennsylvania State University, University Park, PA, USA
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30
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Gong F, Wu X, Wang W. Diversity and function of maize pollen coat proteins: from biochemistry to proteomics. FRONTIERS IN PLANT SCIENCE 2015; 6:199. [PMID: 25870606 PMCID: PMC4378360 DOI: 10.3389/fpls.2015.00199] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 03/12/2015] [Indexed: 05/23/2023]
Abstract
Maize (Zea mays L.) is globally cultivated as one of the most important grain crops. As a wind-pollinated species, maize produces a large quantity of pollen grains that heavier and larger compared to Arabidopsis. Maize is an important model plant in pollen biology of monocots. The pollen coat, the outermost layer of pollen, plays a vital role in pollen-stigma interactions and successful fertilization. Pollen coat proteins (PCPs), which confer species specificity, are required for pollen adhesion, recognition, hydration, and germination on the stigma. Thus, PCPs have attracted intensive research efforts in plant science for decades. However, only a few PCPs in maize have been characterized to date, whereas the functions of most maize PCPs remain unclear. In this review, we summarize the current knowledge of maize PCPs with regard to protein constituents, synthesis and transport, and functions by comparison with the model plant Arabidopsis thaliana and Brassica plants. An understanding of the comprehensive knowledge of maize PCPs will help to illuminate the mechanism by which PCPs are involved in pollen-stigma interactions in maize and other crop plants.
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31
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Sampedro J, Guttman M, Li LC, Cosgrove DJ. Evolutionary divergence of β-expansin structure and function in grasses parallels emergence of distinctive primary cell wall traits. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:108-20. [PMID: 25353668 DOI: 10.1111/tpj.12715] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/19/2014] [Accepted: 10/21/2014] [Indexed: 05/06/2023]
Abstract
Expansins are wall-loosening proteins that promote the extension of primary cell walls without the hydrolysis of major structural components. Previously, proteins from the EXPA (α-expansin) family were found to loosen eudicot cell walls but to be less effective on grass cell walls, whereas the reverse pattern was found for EXPB (β-expansin) proteins obtained from grass pollen. To understand the evolutionary and structural bases for the selectivity of EXPB action, we assessed the extension (creep) response of cell walls from diverse monocot families to EXPA and EXPB treatments. Cell walls from Cyperaceae and Juncaceae (families closely related to grasses) displayed a typical grass response ('β-response'). Walls from more distant monocots, including some species that share with grasses high levels of arabinoxylan, responded preferentially to α-expansins ('α-response'), behaving in this regard like eudicots. An expansin with selective activity for grass cell walls was detected in Cyperaceae pollen, coinciding with the expression of genes from the divergent EXPB-I branch that includes grass pollen β-expansins. The evolutionary origin of this branch was located within Poales on the basis of phylogenetic analyses and its association with the 'sigma' whole-genome duplication. Accelerated evolution in this branch has remodeled the protein surface in contact with the substrate, potentially for binding highly substituted arabinoxylan. We propose that the evolution of the divergent EXPB-I group made a fundamental change in the target and mechanism of wall loosening in the grass lineage possible, involving a new structural role for xylans and the expansins that target them.
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Affiliation(s)
- Javier Sampedro
- Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
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32
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Genome-wide identification and characterization of maize expansin genes expressed in endosperm. Mol Genet Genomics 2014; 289:1061-74. [PMID: 25213600 DOI: 10.1007/s00438-014-0867-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 05/12/2014] [Indexed: 10/24/2022]
Abstract
By promoting cell wall loosening, expansins contribute to cell enlargement during various developmental processes. Nevertheless, the role of expansins in the expansion and development of endosperm--a major seed component whose cell size is significantly associated with grain yield--is poorly understood. To explore associated biological processes and the evolution of expansins in maize, we performed a systematic analysis of the expansin gene family encompassing gene structure, phylogeny, chromosomal location, gene duplication, and gene ontology. A total of 88 maize expansin genes (ZmEXPs) were identified and categorized into three subfamilies according to their phylogenetic relationships. Expression patterns of ZmEXPs were also investigated in nine different tissues by semi-quantitative RT-PCR. The expression of eight ZmEXPs was detected in endosperm, with five showing endosperm-specific expression. Quantitative RT-PCR was used to analyze expression patterns of the eight ZmEXPs in endosperm (10 days after pollination) under abscisic acid (ABA) and gibberellic acid (GA3) treatments. All eight ZmEXPs were found to be significantly regulated by ABA and GA3 in endosperm, suggesting important roles for these hormones in the regulation of ZmEXPs during endosperm development. Our results provide essential information for ZmEXPs cloning and functional exploration, which will assist research on expansin-related mechanisms and contribute to future enhancement of maize grain yield.
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33
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Popescu FD. Molecular biomarkers for grass pollen immunotherapy. World J Methodol 2014; 4:26-45. [PMID: 25237628 PMCID: PMC4145574 DOI: 10.5662/wjm.v4.i1.26] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 01/05/2014] [Accepted: 02/18/2014] [Indexed: 02/06/2023] Open
Abstract
Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines.
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34
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Losada JM, Herrero M. Glycoprotein composition along the pistil of Malus x domestica and the modulation of pollen tube growth. BMC PLANT BIOLOGY 2014; 14:1. [PMID: 25316555 PMCID: PMC3890559 DOI: 10.1186/1471-2229-14-1] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 12/20/2013] [Indexed: 05/17/2023]
Abstract
BACKGROUND The characteristics of pollen tube growth are not constant, but display distinct patterns of growth within the different tissues of the pistil. In the stigma, the growth rate is slow and autotrophic, whereas in the style, it is rapid and heterotrophic. Very little is known about the interactions between these distinct maternal tissues and the traversing pollen tube and the role of this interaction on the observed metabolism. In this work we characterise pollen tube growth in the apple flower and look for differences in glycoprotein epitope localization between two different maternal tissues, the stigma and the style. RESULTS While immunocytochemically-detected arabinogalactan proteins were present at high levels in the stigma, they were not detected in the transmitting tissue of the style, where extensins were abundant. Whereas extensins remained at high levels in unpollinated pistils, they were no longer present in the style following pollen tube passage. Similarily, while abundant in unpollinated styles, insoluble polysaccharides such as β-glucans, were depleted in pollinated pistils. CONCLUSIONS The switch from autotropic to heterotrophic pollen tube growth correlates spatially with a change of glycoprotein epitopes between the stigma and the style. The depletion of extensins and polysaccharides following pollen tube passage in the style suggest a possible contribution to the acceleration of heterotrophic pollen tube growth, which would imply an active contribution of female tissues on prezygotic male-female crosstalk.
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Affiliation(s)
- Juan M Losada
- Pomology Department, Aula Dei Experimental Station CSIC, Apdo 13034, 50080 Zaragoza, Spain
- Present address: Arnold Arboretum of Harvard University, 1300 Centre Street, 02131 Boston, MA, USA
| | - Maria Herrero
- Pomology Department, Aula Dei Experimental Station CSIC, Apdo 13034, 50080 Zaragoza, Spain
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35
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Zhang S, Xu R, Gao Z, Chen C, Jiang Z, Shu H. A genome-wide analysis of the expansin genes in Malus × Domestica. Mol Genet Genomics 2013; 289:225-36. [PMID: 24378555 DOI: 10.1007/s00438-013-0796-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 11/18/2013] [Indexed: 01/24/2023]
Abstract
Expansins were first identified as cell wall-loosening proteins; they are involved in regulating cell expansion, fruits softening and many other physiological processes. However, our knowledge about the expansin family members and their evolutionary relationships in fruit trees, such as apple, is limited. In this study, we identified 41 members of the expansin gene family in the genome of apple (Malus × Domestica L. Borkh). Phylogenetic analysis revealed that expansin genes in apple could be divided into four subfamilies according to their gene structures and protein motifs. By phylogenetic analysis of the expansins in five plants (Arabidopsis, rice, poplar, grape and apple), the expansins were divided into 17 subgroups. Our gene duplication analysis revealed that whole-genome and chromosomal-segment duplications contributed to the expansion of Mdexpansins. The microarray and expressed sequence tag (EST) data showed that 34 Mdexpansin genes could be divided into five groups by the EST analysis; they may also play different roles during fruit development. An expression model for MdEXPA16 and MdEXPA20 showed their potential role in developing fruit. Overall, our study provides useful data and novel insights into the functions and regulatory mechanisms of the expansin genes in apple, as well as their evolution and divergence. As the first step towards genome-wide analysis of the expansin genes in apple, our results have established a solid foundation for future studies on the function of the expansin genes in fruit development.
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Affiliation(s)
- Shizhong Zhang
- State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Technology, Shandong Agricultural University, Taian, Shandong, 271018, People's Republic of China
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36
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Hepler PK, Rounds CM, Winship LJ. Control of cell wall extensibility during pollen tube growth. MOLECULAR PLANT 2013; 6:998-1017. [PMID: 23770837 PMCID: PMC4043104 DOI: 10.1093/mp/sst103] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In this review, we address the question of how the tip-growing pollen tube achieves its rapid rate of elongation while maintaining an intact cell wall. Although turgor is essential for growth to occur, the local expansion rate is controlled by local changes in the viscosity of the apical wall. We focus on several different structures and underlying processes that are thought to be major participants including exocytosis, the organization and activity of the actin cytoskeleton, calcium and proton physiology, and cellular energetics. We think that the actin cytoskeleton, in particular the apical cortical actin fringe, directs the flow of vesicles to the apical domain, where they fuse with the plasma membrane and contribute their contents to the expanding cell wall. While pH gradients, as generated by a proton-ATPase located on the plasma membrane along the side of the clear zone, may regulate rapid actin turnover and new polymerization in the fringe, the tip-focused calcium gradient biases secretion towards the polar axis. The recent data showing that exocytosis of new wall material precedes and predicts the process of cell elongation provide support for the idea that the intussusception of newly secreted pectin contributes to decreases in apical wall viscosity and to cell expansion. Other prime factors will be the localization and activity of the enzyme pectin methyl-esterase, and the chelation of calcium by pectic acids. Finally, we acknowledge a role for reactive oxygen species in the control of wall viscosity.
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Affiliation(s)
- Peter K Hepler
- Biology Department, University of Massachusetts, Amherst, MA 01003, USA.
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37
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da Costa ML, Pereira LG, Coimbra S. Growth Media Induces Variation in Cell Wall Associated Gene Expression in Arabidopsis thaliana Pollen Tube. PLANTS 2013; 2:429-40. [PMID: 27137385 PMCID: PMC4844376 DOI: 10.3390/plants2030429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 06/03/2013] [Accepted: 06/18/2013] [Indexed: 01/28/2023]
Abstract
The influence of three different pollen germination media on the transcript profile of Arabidopsis pollen tubes has been assessed by real-time PCR on a selection of cell wall related genes, and by a statistical analysis of microarray Arabidopsis pollen tube data sets. The qPCR assays have shown remarkable differences on the transcript levels of specific genes depending upon the formulation of the germination medium used. With the aid of principal component analysis performed on existing microarray data, a subset of genes has been identified that is more prone to produce diverging transcript levels. A functional classification of those genes showed that the clusters with higher number of members were those for hydrolase activity (based in molecular function) and for cell wall (based in cellular component). Taken together, these results may indicate that the nutrient composition of the pollen germination media influences pollen tube metabolism and that caution must be taken when interpreting transcriptomic data of pollen tubes.
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Affiliation(s)
- Mário Luís da Costa
- BioFIG, Center for Biodiversity, Functional and Integrative Genomics, Biology Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n 4169-007 Porto, Portugal.
| | - Luís Gustavo Pereira
- BioFIG, Center for Biodiversity, Functional and Integrative Genomics, Biology Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n 4169-007 Porto, Portugal.
| | - Sílvia Coimbra
- BioFIG, Center for Biodiversity, Functional and Integrative Genomics, Biology Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n 4169-007 Porto, Portugal.
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38
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Carey RE, Hepler NK, Cosgrove DJ. Selaginella moellendorffii has a reduced and highly conserved expansin superfamily with genes more closely related to angiosperms than to bryophytes. BMC PLANT BIOLOGY 2013; 13:4. [PMID: 23286898 PMCID: PMC3680112 DOI: 10.1186/1471-2229-13-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 12/22/2012] [Indexed: 05/10/2023]
Abstract
BACKGROUND Expansins are plant cell wall loosening proteins encoded by a large superfamily of genes, consisting of four families named EXPA, EXPB, EXLA, and EXLB. The evolution of the expansin superfamily is well understood in angiosperms, thanks to synteny-based evolutionary studies of the gene superfamily in Arabidopsis, rice, and Populus. Analysis of the expansin superfamily in the moss Physcomitrella patens revealed a superfamily without EXLA or EXLB genes that has evolved considerably and independently of angiosperm expansins. The sequencing of the Selaginella moellendorffii genome has allowed us to extend these analyses into an early diverging vascular plant. RESULTS The expansin superfamily in Selaginella moellendorffii has now been assembled from genomic scaffolds. A smaller (and less diverse) superfamily is revealed, consistent with studies of other gene families in Selaginella. Selaginella has an expansin superfamily, which, like Physcomitrella, lacks EXLA or EXLB genes, but does contain two EXPA genes that are related to a particular Arabidopsis-rice clade involved in root hair development. CONCLUSIONS From sequence-based phylogenetic analysis, most Selaginella expansins lie outside the Arabidopsis-rice clades, leading us to estimate the minimum number of expansins present in the last common ancestor of Selaginella and angiosperms at 2 EXPA genes and 1 EXPB gene. These results confirm Selaginella as an important intermediary between bryophytes and angiosperms.
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Affiliation(s)
- Robert E Carey
- Department of Biology, Lebanon Valley College, 101 N. College Ave., Annville, PA, 17003, USA
- Department of Biology, The Pennsylvania State University, 208 Mueller Lab, University Park, PA, 16802, USA
| | - Nathan K Hepler
- Program in Biochemistry and Molecular Biology, Lebanon Valley College, 101 N. College Ave., Annville, PA, 17003, USA
| | - Daniel J Cosgrove
- Department of Biology, The Pennsylvania State University, 208 Mueller Lab, University Park, PA, 16802, USA
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Sang YL, Xu M, Ma FF, Chen H, Xu XH, Gao XQ, Zhang XS. Comparative proteomic analysis reveals similar and distinct features of proteins in dry and wet stigmas. Proteomics 2012; 12:1983-98. [PMID: 22623354 DOI: 10.1002/pmic.201100407] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 03/21/2012] [Indexed: 11/09/2022]
Abstract
Angiosperm stigma supports compatible pollen germination and tube growth, resulting in fertilization and seed production. Stigmas are mainly divided into two types, dry and wet, according to the absence or presence of exudates on their surfaces. Here, we used 2DE and MS to identify proteins specifically and preferentially expressed in the stigmas of maize (Zea Mays, dry stigma) and tobacco (Nicotiana tabacum, wet stigma), as well as proteins rinsed from the surface of the tobacco stigma. We found that the specifically and preferentially expressed proteins in maize and tobacco stigmas share similar distributions in functional categories. However, these proteins showed important difference between dry and wet stigmas in a few aspects, such as protein homology in "signal transduction" and "lipid metabolism," relative expression levels of proteins containing signal peptides and proteins in "defense and stress response." These different features might be related to the specific structures and functions of dry and wet stigmas. The possible roles of some stigma-expressed proteins were discussed. Our results provide important information on functions of proteins in dry and wet stigmas and reveal aspects of conservation and divergence between dry and wet stigmas at the proteomic level.
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Affiliation(s)
- Ya Lin Sang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
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Zaidi MA, O'Leary S, Wu S, Gleddie S, Eudes F, Laroche A, Robert LS. A molecular and proteomic investigation of proteins rapidly released from triticale pollen upon hydration. PLANT MOLECULAR BIOLOGY 2012; 79:101-21. [PMID: 22367549 DOI: 10.1007/s11103-012-9897-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 02/15/2012] [Indexed: 05/08/2023]
Abstract
Analysis of Triticale (×Triticosecale Wittmack cv. AC Alta) mature pollen proteins quickly released upon hydration was performed using two-dimensional gel electrophoresis followed by mass spectrometry. A total of 17 distinct protein families were identified and these included expansins, profilins, and various enzymes, many of which are pollen allergens. The corresponding genes were obtained and expression studies revealed that the majority of these genes were only expressed in developing anthers and pollen. Some genes including glucanase, glutathione peroxidase, glutaredoxin, and a profilin were found to be widely expressed in different reproductive and vegetative tissues. Group 11 pollen allergens, polygalacturonase, and actin depolymerizing factor were characterized for the first time in the Triticeae. This study represents a distinctive combination of proteomic and molecular analyses of the major cereal pollen proteins released upon hydration and therefore at the forefront of pollen-stigma interactions.
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Affiliation(s)
- Mohsin A Zaidi
- Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada
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Eberle CA, Clasen BM, Anderson NO, Smith AG. A novel pollen tube growth assay utilizing a transmitting tract-ablated Nicotiana tabacum style. SEXUAL PLANT REPRODUCTION 2012; 25:27-37. [PMID: 22101491 DOI: 10.1007/s00497-011-0177-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 10/25/2011] [Indexed: 01/12/2023]
Abstract
Sexual plant reproduction requires multiple pollen-pistil interactions from the stigma (pollen adhesion, hydration, and germination) to the ovary (fertilization). Understanding the factors that regulate pollen tube growth is critical to understanding the processes essential to sexual reproduction. Many pollen tube growth assays (PTGAs) have shorter and slower pollen tube growth when compared to pollen tube growth through the style. The identification and study of factors that regulate pollen tube growth have been impeded by a lack of an efficient and reproducible PTGA. The objective of this research is to develop a robust assay for Nicotiana tabacum pollen tube growth in an environment that supports sustained and normal growth yet is amenable to testing the effects of specific factors. In this paper, we introduce a novel PTGA, which uses pistils from N. tabacum that lack a mature transmitting tract (TT) due to tissue-specific ablation. The TT-ablated style supports normal pollen tube growth and the hollow structure of the style allows modification of the growth environment by direct injection of test material. This PTGA is robust and allows for rapid and accurate measurement of pollen tube length and pollen tube morphology, supporting pollen tube growth from 20 to 35°C and at pH ranging from 4.8 to 7.6. Use of the ablated style for a PTGA is a novel method for the culture of pollen tubes with sustained growth in vivo while permitting the application of treatments to the growing pollen tubes.
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Affiliation(s)
- Carrie A Eberle
- Department of Horticultural Science, 1970 Folwell Avenue, St. Paul, MN 55108, USA.
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Tabuchi A, Li LC, Cosgrove DJ. Matrix solubilization and cell wall weakening by β-expansin (group-1 allergen) from maize pollen. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 68:546-59. [PMID: 21749508 DOI: 10.1111/j.1365-313x.2011.04705.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Beta-expansins accumulate to high levels in grass pollen, a feature apparently unique to grasses. These proteins, which are major human allergens, facilitate pollen tube penetration of the maize stigma and style (the silk). Here we report that treatment of maize silk cell walls with purified β-expansin from maize pollen led to solubilization of wall matrix polysaccharides, dominated by feruloyated highly substituted glucuronoarabinoxylan (60%) and homogalacturonan (35%). Such action was selective for cell walls of grasses, and indicated a target preferentially found in grass cell walls, probably the highly substituted glucuronoarabinoxylan. Several tests for lytic activities by β-expansin were negative and polysaccharide solubilization had weak temperature dependence, which indicated a non-enzymatic process. Concomitant with matrix solubilization, β-expansin treatment induced creep, reduced the breaking force and increased the plastic compliance of wall specimens. From comparisons of the pH dependencies of these processes, we conclude that matrix solubilization was linked closely to changes in wall plasticity and breaking force, but not so closely coupled to cell wall creep. Because matrix solubilization and increased wall plasticity have not been found with other expansins, we infer that these novel activities are linked to the specialized role of grass pollen β-expansins in promotion of penetration of the pollen tube through the stigma and style, most likely by weakening the middle lamella.
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Affiliation(s)
- Akira Tabuchi
- Department of Biology, 208 Mueller Laboratory, Pennsylvania State University, University Park, PA 16802, USA
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Dresselhaus T, Lausser A, Márton ML. Using maize as a model to study pollen tube growth and guidance, cross-incompatibility and sperm delivery in grasses. ANNALS OF BOTANY 2011; 108:727-37. [PMID: 21345919 PMCID: PMC3170146 DOI: 10.1093/aob/mcr017] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND In contrast to animals and lower plants such as mosses and ferns, sperm cells of flowering plants (angiosperms) are immobile and require transportation to the female gametes via the vegetative pollen tube cell to achieve double fertilization. The path of the pollen tube towards the female gametophyte (embryo sac) has been intensively studied in many intra- and interspecific crossing experiments with the aim of increasing the gene pool of crop plants for greater yield, improved biotic and abiotic stress resistance, and for introducing new agronomic traits. Many attempts to hybridize different species or genotypes failed due to the difficulty for the pollen tubes in reaching the female gametophyte. Detailed studies showed that these processes are controlled by various self-incompatible (intraspecific) and cross-incompatible (interspecific) hybridization mechanisms. SCOPE Understanding the molecular mechanisms of crossing barriers is therefore of great interest in plant reproduction, evolution and breeding research. In particular, pre-zygotic hybridization barriers related to pollen tube germination, growth, guidance and sperm delivery, which are considered the major hybridization controls in nature and thus also contribute to species isolation and speciation, have been intensively investigated. Despite this general interest, surprisingly little is known about these processes in the most important agronomic plant family, the Gramineae, Poaceae or grasses. Small polymorphic proteins and their receptors, degradation of sterility locus proteins and general compounds such as calcium, γ-aminobutyric acid or nitric oxide have been shown to be involved in progamic pollen germination, adhesion, tube growth and guidance, as well as sperm release. Most advances have been made in the Brassicaceae, Papaveraceae, Linderniaceae and Solanaceae families including their well-understood self-incompatibility (SI) systems. Grass species evolved similar mechanisms to control the penetration and growth of self-pollen to promote intraspecific outcrossing and to prevent fertilization by alien sperm cells. However, in the Poaceae, the underlying molecular mechanisms are still largely unknown. CONCLUSIONS We propose to develop maize (Zea mays) as a model to investigate the above-described processes to understand the associated intra- and interspecific crossing barriers in grasses. Many genetic, cellular and biotechnological tools including the completion of a reference genome (inbred line B73) have been established in the last decade and many more maize inbred genomes are expected to be available soon. Moreover, a cellular marker line database as well as large transposon insertion collections and improved Agrobacterium transformation protocols are now available. Additionally, the processes described above are well studied at the morphological level and a number of mutants have been described already, awaiting disclosure of the relevant genes. The identification of the first key players in pollen tube growth, guidance and burst show maize to be an excellent grass model to investigate these processes in more detail. Here we provide an overview of our current understanding of these processes in Poaceae with a focus on maize, and also include relevant discoveries in eudicot model species.
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Affiliation(s)
- Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
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Ge W, Song Y, Zhang C, Zhang Y, Burlingame AL, Guo Y. Proteomic analyses of apoplastic proteins from germinating Arabidopsis thaliana pollen. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1964-73. [PMID: 21798377 DOI: 10.1016/j.bbapap.2011.07.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/28/2011] [Accepted: 07/13/2011] [Indexed: 12/30/2022]
Abstract
Pollen grains play important roles in the reproductive processes of flowering plants. The roles of apoplastic proteins in pollen germination and in pollen tube growth are comparatively less well understood. To investigate the functions of apoplastic proteins in pollen germination, the global apoplastic proteins of mature and germinated Arabidopsis thaliana pollen grains were prepared for differential analyses by using 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) saturation labeling techniques. One hundred and three proteins differentially expressed (p value≤0.01) in pollen germinated for 6h compared with un-germination mature pollen, and 98 spots, which represented 71 proteins, were identified by LC-MS/MS. By bioinformatics analysis, 50 proteins were identified as secreted proteins. These proteins were mainly involved in cell wall modification and remodeling, protein metabolism and signal transduction. Three of the differentially expressed proteins were randomly selected to determine their subcellular localizations by transiently expressing YFP fusion proteins. The results of subcellular localization were identical with the bioinformatics prediction. Based on these data, we proposed a model for apoplastic proteins functioning in pollen germination and pollen tube growth. These results will lead to a better understanding of the mechanisms of pollen germination and pollen tube growth.
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Affiliation(s)
- Weina Ge
- Institute of Molecular Cell Biology, Hebei Normal University, Shijiazhuang, Hebei Province, People's Republic of China
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Lukschal A, Fuhrmann J, Sobanov J, Neumann D, Wallmann J, Knittelfelder R, Hemmer W, Scheiner O, Vogel M, Stadler BM, Jensen-Jarolim E, Szalai K. Anti-idiotypic Fab Fragments Image a Conserved N-terminal Epitope Patch of Grass Pollen Allergen Phl p 1. ACTA ACUST UNITED AC 2011; 4:16-23. [PMID: 22318973 DOI: 10.2174/1874838401104010016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND AIMS: Naturally occurring anti-idiotypic antibodies structurally mimic the original antibody epitope. Anti-idiotypes, therefore, are interesting tools for the portrayal of conformational B-cell epitopes of allergens. In this study we used this strategy particularly for major timothy grass pollen (Phleum pratense) allergen Phl p 1. METHODS AND RESULTS: We used a combinatorial phage display library constructed from the peripheral IgG repertoire of a grass pollen allergic patient which was supposed to contain anti-idiotypic Fab specificities. Using purified anti-Phl p 1 IgG for biopanning, several Fab displaying phage clones could be isolated. 100 amplified colonies were screened for their binding capacity to anti-Phl p 1-specific antibodies, finally resulting in four distinct Fab clones according to sequence analysis. Interestingly, heavy chains of all clones derived from the same germ line sequence and showed high homology in their CDRs. Projecting their sequence information on the surface of the natural allergen Phl p 1 (PDB ID: 1N10) indicated matches on the N-terminal domain of the homo-dimeric allergen, including the bridging region between the two monomers. The resulting epitope patches were formed by spatially distant sections of the primary allergen sequence. CONCLUSION: In this study we report that anti-idiotypic specificities towards anti-Phl p 1 IgG, selected from a Fab library of a grass pollen allergic patient, mimic a conformational epitope patch being distinct from a previously reported IgE epitope area.
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Affiliation(s)
- Anna Lukschal
- Department of Pathophysiology and Allergy Research; Center of Pathophysiology, Infectiology & Immunology; Medical University of Vienna, Vienna, Austria
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Georgelis N, Tabuchi A, Nikolaidis N, Cosgrove DJ. Structure-function analysis of the bacterial expansin EXLX1. J Biol Chem 2011; 286:16814-23. [PMID: 21454649 DOI: 10.1074/jbc.m111.225037] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We made use of EXLX1, an expansin from Bacillus subtilis, to investigate protein features essential for its plant cell wall binding and wall loosening activities. We found that the two expansin domains, D1 and D2, need to be linked for wall extension activity and that D2 mediates EXLX1 binding to whole cell walls and to cellulose via distinct residues on the D2 surface. Binding to cellulose is mediated by three aromatic residues arranged linearly on the putative binding surface that spans D1 and D2. Mutation of these three residues to alanine eliminated cellulose binding and concomitantly eliminated wall loosening activity measured either by cell wall extension or by weakening of filter paper but hardly affected binding to whole cell walls, which is mediated by basic residues located on other D2 surfaces. Mutation of these basic residues to glutamine reduced cell wall binding but not wall loosening activities. We propose domain D2 as the founding member of a new carbohydrate binding module family, CBM63, but its function in expansin activity apparently goes beyond simply anchoring D1 to the wall. Several polar residues on the putative binding surface of domain D1 are also important for activity, most notably Asp82, whose mutation to alanine or asparagine completely eliminated wall loosening activity. The functional insights based on this bacterial expansin may be extrapolated to the interactions of plant expansins with cell walls.
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Affiliation(s)
- Nikolaos Georgelis
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Generating a Cellular Protuberance: Mechanics of Tip Growth. MECHANICAL INTEGRATION OF PLANT CELLS AND PLANTS 2011. [DOI: 10.1007/978-3-642-19091-9_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Kapu NUS, Cosgrove DJ. Changes in growth and cell wall extensibility of maize silks following pollination. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:4097-107. [PMID: 20656797 PMCID: PMC2935878 DOI: 10.1093/jxb/erq225] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 06/23/2010] [Accepted: 06/28/2010] [Indexed: 05/18/2023]
Abstract
In response to pollination maize silks undergo an accelerated process of senescence which involves an inhibition of elongation. To gain insight into the mechanism underlying this growth response, the relationships among silk elongation kinetics, cell wall biophysical properties, pollen tube growth, and expansin protein abundance were investigated. The inhibition of silk elongation became apparent beyond 12 h after pollination. Pollinated walls were less responsive in assays of extension induced by pollen beta-expansin. Expansin protein abundance and endogenous expansin activity were not considerably reduced after pollination. Silk wall plastic compliance was significantly reduced 6 h post-pollination and beyond, suggesting that the wall undergoes structural modifications leading to its rigidification in response to pollination. The reduction in the plastic compliance occurred locally and progressively, shortly after pollen tubes traversed through a region of silk. Though numerous pollen grains germinated and initiated pollen tubes at the silk tip, the density of pollen tubes gradually declined along the length of the silk and only 1-2 reached the ovary even 24 h after pollination. These results support the notion that pollination-induced cell wall rigidification plays multiple roles in maize reproduction, including inhibition of silk growth and prevention of polyspermy.
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Affiliation(s)
- Nuwan U Sella Kapu
- Department of Biology and Intercollege Program in Plant Biology, 208 Mueller Laboratory, The Pennsylvania State University, University Park, PA 16802, USA.
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Abstract
Pollen tube growth and guidance in the female tissues of flowering plants is a long-studied and anatomically well-described process. A large number of gene products and chemical compounds involved have been identified in the last 20 years, and some underlying molecular mechanisms including self-incompatibility in the Brassicaceae, Solanaceae and Papaveraceae are now well understood. However, the largest part of the pollen tube pathway inside the transmitting tract towards the ovule harbouring the female gametophyte still requires intensive investigations. Especially in the economically most import plant family, the Poaceae or grasses, progamic pollen tube development is barely understood. Using maize as a model, we propose to divide pollen tube germination, growth and guidance towards the female gametophyte into five distinct phases. The model is adapted from Arabidopsis thaliana, taking anatomical differences and novel genetic and cellular studies into consideration. With the exception of Phase V, all phases seem to be under sporophytic control in grasses.
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Geitmann A. How to shape a cylinder: pollen tube as a model system for the generation of complex cellular geometry. ACTA ACUST UNITED AC 2009; 23:63-71. [PMID: 20165964 DOI: 10.1007/s00497-009-0121-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 10/31/2009] [Indexed: 02/01/2023]
Abstract
Expansive growth in plant cells is a formidable problem for biophysical studies, and the mechanical principles governing the generation of complex cellular geometries are still poorly understood. Pollen, the male gametophyte stage of the flowering plants, is an excellent model system for the investigation of the mechanics of complex growth processes. The initiation of pollen tube growth requires first of all, the spatially confined formation of a protuberance. This process must be controlled by the mechanical properties of the cell wall, since turgor is a non-vectorial force. In the elongating tube, cell wall expansion is confined to the apex of the cell, requiring the tubular region to be stabilized against turgor-induced tensile stress. Tip focused surface expansion must be coordinated with the supply of cell wall material to this region requiring the precise, logistical control of intracellular transport processes. The advantage of such a demanding mechanism is the high efficiency it confers on the pollen tube in leading an invasive way of life.
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Affiliation(s)
- Anja Geitmann
- Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, 4101 rue Sherbrooke est, Montréal, QC, H1X 2B2, Canada.
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