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Robinson R, Sprott D, Couroux P, Routly E, Labbé N, Xing T, Robert LS. The triticale mature pollen and stigma proteomes - assembling the proteins for a productive encounter. J Proteomics 2023; 278:104867. [PMID: 36870675 DOI: 10.1016/j.jprot.2023.104867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/13/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023]
Abstract
Triticeae crops are major contributors to global food production and ensuring their capacity to reproduce and generate seeds is critical. However, despite their importance our knowledge of the proteins underlying Triticeae reproduction is severely lacking and this is not only true of pollen and stigma development, but also of their pivotal interaction. When the pollen grain and stigma are brought together they have each accumulated the proteins required for their intended meeting and accordingly studying their mature proteomes is bound to reveal proteins involved in their diverse and complex interactions. Using triticale as a Triticeae representative, gel-free shotgun proteomics was used to identify 11,533 and 2977 mature stigma and pollen proteins respectively. These datasets, by far the largest to date, provide unprecedented insights into the proteins participating in Triticeae pollen and stigma development and interactions. The study of the Triticeae stigma has been particularly neglected. To begin filling this knowledge gap, a developmental iTRAQ analysis was performed revealing 647 proteins displaying differential abundance as the stigma matures in preparation for pollination. An in-depth comparison to an equivalent Brassicaceae analysis divulged both conservation and diversification in the makeup and function of proteins involved in the pollen and stigma encounter. SIGNIFICANCE: Successful pollination brings together the mature pollen and stigma thus initiating an intricate series of molecular processes vital to crop reproduction. In the Triticeae crops (e.g. wheat, barley, rye, triticale) there persists a vast deficit in our knowledge of the proteins involved which needs to be addressed if we are to face the many upcoming challenges to crop production such as those associated with climate change. At maturity, both the pollen and stigma have acquired the protein complement necessary for their forthcoming encounter and investigating their proteomes will inevitably provide unprecedented insights into the proteins enabling their interactions. By combining the analysis of the most comprehensive Triticeae pollen and stigma global proteome datasets to date with developmental iTRAQ investigations, proteins implicated in the different phases of pollen-stigma interaction enabling pollen adhesion, recognition, hydration, germination and tube growth, as well as those underlying stigma development were revealed. Extensive comparisons between equivalent Triticeae and Brassiceae datasets highlighted both the conservation of biological processes in line with the shared goal of activating the pollen grain and promoting pollen tube invasion of the pistil to effect fertilization, as well as the significant distinctions in their proteomes consistent with the considerable differences in their biochemistry, physiology and morphology.
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Affiliation(s)
- Reneé Robinson
- Ottawa Research and Development Centre, 960 Carling Ave., Ottawa, Ontario K1A 0C6, Canada; Carleton University, Department of Biology, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - David Sprott
- Ottawa Research and Development Centre, 960 Carling Ave., Ottawa, Ontario K1A 0C6, Canada
| | - Philippe Couroux
- Ottawa Research and Development Centre, 960 Carling Ave., Ottawa, Ontario K1A 0C6, Canada
| | - Elizabeth Routly
- Ottawa Research and Development Centre, 960 Carling Ave., Ottawa, Ontario K1A 0C6, Canada
| | - Natalie Labbé
- Ottawa Research and Development Centre, 960 Carling Ave., Ottawa, Ontario K1A 0C6, Canada
| | - Tim Xing
- Carleton University, Department of Biology, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Laurian S Robert
- Ottawa Research and Development Centre, 960 Carling Ave., Ottawa, Ontario K1A 0C6, Canada.
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Çetinbaş-Genç A, Conti V, Cai G. Let's shape again: the concerted molecular action that builds the pollen tube. PLANT REPRODUCTION 2022; 35:77-103. [PMID: 35041045 DOI: 10.1007/s00497-022-00437-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
The pollen tube is being subjected to control by a complex network of communication that regulates its shape and the misfunction of a single component causes specific deformations. In flowering plants, the pollen tube is a tubular extension of the pollen grain required for successful sexual reproduction. Indeed, maintaining the unique shape of the pollen tube is essential for the pollen tube to approach the embryo sac. Many processes and molecules (such as GTPase activity, phosphoinositides, Ca2+ gradient, distribution of reactive oxygen species and nitric oxide, nonuniform pH values, organization of the cytoskeleton, balance between exocytosis and endocytosis, and cell wall structure) play key and coordinated roles in maintaining the cylindrical shape of pollen tubes. In addition, the above factors must also interact with each other so that the cell shape is maintained while the pollen tube follows chemical signals in the pistil that guide it to the embryo sac. Any intrinsic changes (such as erroneous signals) or extrinsic changes (such as environmental stresses) can affect the above factors and thus fertilization by altering the tube morphology. In this review, the processes and molecules that enable the development and maintenance of the unique shape of pollen tubes in angiosperms are presented emphasizing their interaction with specific tube shape. Thus, the purpose of the review is to investigate whether specific deformations in pollen tubes can help us to better understand the mechanism underlying pollen tube shape.
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Affiliation(s)
- Aslıhan Çetinbaş-Genç
- Department of Biology, Marmara University, Göztepe Campus, 34722, Kadıköy, Istanbul, Turkey.
| | - Veronica Conti
- Department of Life Sciences, University of Siena, via Mattioli 4, 53100, Siena, Italy
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, via Mattioli 4, 53100, Siena, Italy
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Hao G, Zhao X, Zhang M, Ying J, Yu F, Li S, Zhang Y. Vesicle trafficking in
Arabidopsis
pollen tubes. FEBS Lett 2022; 596:2231-2242. [DOI: 10.1002/1873-3468.14343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Guang‐Jiu Hao
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Xin‐Ying Zhao
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | | | - Jun Ying
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Fei Yu
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Sha Li
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Yan Zhang
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
- College of Life Sciences Nankai University China
- Frontiers Science Center for Cell Responses Nankai University China
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Plasma membrane phospholipid signature recruits the plant exocyst complex via the EXO70A1 subunit. Proc Natl Acad Sci U S A 2021; 118:2105287118. [PMID: 34470819 DOI: 10.1073/pnas.2105287118] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Polarized exocytosis is essential for many vital processes in eukaryotic cells, where secretory vesicles are targeted to distinct plasma membrane domains characterized by their specific lipid-protein composition. Heterooctameric protein complex exocyst facilitates the vesicle tethering to a target membrane and is a principal cell polarity regulator in eukaryotes. The architecture and molecular details of plant exocyst and its membrane recruitment have remained elusive. Here, we show that the plant exocyst consists of two modules formed by SEC3-SEC5-SEC6-SEC8 and SEC10-SEC15-EXO70-EXO84 subunits, respectively, documenting the evolutionarily conserved architecture within eukaryotes. In contrast to yeast and mammals, the two modules are linked by a plant-specific SEC3-EXO70 interaction, and plant EXO70 functionally dominates over SEC3 in the exocyst recruitment to the plasma membrane. Using an interdisciplinary approach, we found that the C-terminal part of EXO70A1, the canonical EXO70 isoform in Arabidopsis, is critical for this process. In contrast to yeast and animal cells, the EXO70A1 interaction with the plasma membrane is mediated by multiple anionic phospholipids uniquely contributing to the plant plasma membrane identity. We identified several evolutionary conserved EXO70 lysine residues and experimentally proved their importance for the EXO70A1-phospholipid interactions. Collectively, our work has uncovered plant-specific features of the exocyst complex and emphasized the importance of the specific protein-lipid code for the recruitment of peripheral membrane proteins.
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