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von Aderkas P, Little S, Nepi M, Guarnieri M, Antony M, Takaso T. Composition of Sexual Fluids in Cycas revoluta Ovules During Pollination and Fertilization. THE BOTANICAL REVIEW; INTERPRETING BOTANICAL PROGRESS 2022; 88:453-484. [PMID: 36506282 PMCID: PMC9726676 DOI: 10.1007/s12229-021-09271-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/24/2021] [Indexed: 06/17/2023]
Abstract
UNLABELLED The composition of fluids that mediate fertilization in cycads is described for the first time. Using tandem mass spectrometry, proteomes of two stages of fluid production, megagametophyte fluid and archegonial chamber fluid production, are compared in Cycas revoluta. These were compared with the proteome of another sexual fluid produced by ovules, the pollination drop proteins. Cycad ovules produce complex liquids immediately prior fertilization. Compared with the pollination drops that mainly had few proteins in classes involved in defense and carbohydrate modification, megagametophyte fluid and archegonial chamber fluid had larger proteomes with many more protein classes, e.g. proteins involved in programmed cell death. Using high-performance liquid chromatography, megagametophyte fluid and archegonial chamber fluid were shown to have elevated concentrations of smaller molecular weight molecules including glucose, pectin and glutamic acid. Compared to megagametophyte fluid, archegonial chamber fluid had elevated pH as well as higher osmolality. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12229-021-09271-1.
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Affiliation(s)
- Patrick von Aderkas
- Department of Biology, Centre for Forest Biology, University of Victoria, Victoria, BC V8W 3N5 Canada
| | - Stefan Little
- Department of Biology, Centre for Forest Biology, University of Victoria, Victoria, BC V8W 3N5 Canada
| | - Massimo Nepi
- Department of Life Sciences, University of Siena, San Miniato, via Aldo Moro, 2, Via Pier Andrea Mattioli, 4, 53100 Siena, Italy
| | - Massimo Guarnieri
- Department of Life Sciences, University of Siena, San Miniato, via Aldo Moro, 2, Via Pier Andrea Mattioli, 4, 53100 Siena, Italy
| | - Madeline Antony
- Department of Biology, Centre for Forest Biology, University of Victoria, Victoria, BC V8W 3N5 Canada
| | - Tokushiro Takaso
- Tropical Biosphere Research Center, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Okinawa, 903-0213 Japan
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Breygina M, Klimenko E, Schekaleva O. Pollen Germination and Pollen Tube Growth in Gymnosperms. PLANTS (BASEL, SWITZERLAND) 2021; 10:1301. [PMID: 34206892 PMCID: PMC8309077 DOI: 10.3390/plants10071301] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 01/08/2023]
Abstract
Pollen germination and pollen tube growth are common to all seed plants, but these processes first developed in gymnosperms and still serve for their successful sexual reproduction. The main body of data on the reproductive physiology, however, was obtained on flowering plants, and one should be careful to extrapolate the discovered patterns to gymnosperms. In recent years, physiological studies of coniferous pollen have been increasing, and both the features of this group and the similarities with flowering plants have already been identified. The main part of the review is devoted to physiological studies carried out on conifer pollen. The main properties and diversity of pollen grains and pollination strategies in gymnosperms are described.
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Affiliation(s)
- Maria Breygina
- Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia; (E.K.); (O.S.)
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Hou C, Saunders RMK, Deng N, Wan T, Su Y. Pollination Drop Proteome and Reproductive Organ Transcriptome Comparison in Gnetum Reveals Entomophilous Adaptation. Genes (Basel) 2019; 10:E800. [PMID: 31614866 PMCID: PMC6826882 DOI: 10.3390/genes10100800] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/30/2019] [Accepted: 10/11/2019] [Indexed: 11/16/2022] Open
Abstract
Gnetum possesses morphologically bisexual but functionally unisexual reproductive structures that exude sugary pollination drops to attract insects. Previous studies have revealed that the arborescent species (G. gnemon L.) and the lianoid species (G. luofuense C.Y.Cheng) possess different pollination syndromes. This study compared the proteome in the pollination drops of these two species using label-free quantitative techniques. The transcriptomes of fertile reproductive units (FRUs) and sterile reproductive units (SRUs) for each species were furthermore compared using Illumina Hiseq sequencing, and integrated proteomic and transcriptomic analyses were subsequently performed. Our results show that the differentially expressed proteins between FRUs and SRUs were involved in carbohydrate metabolism, the biosynthesis of amino acids and ovule defense. In addition, the differentially expressed genes between the FRUs and SRUs (e.g., MADS-box genes) were engaged in reproductive development and the formation of pollination drops. The integrated protein-transcript analyses revealed that FRUs and their exudates were relatively conservative while the SRUs and their exudates were more diverse, probably functioning as pollinator attractants. The evolution of reproductive organs appears to be synchronized with changes in the pollination drop proteome of Gnetum, suggesting that insect-pollinated adaptations are not restricted to angiosperms but also occur in gymnosperms.
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Affiliation(s)
- Chen Hou
- School of Life Sciences, Sun Yat-Sen University, Xingangxi Road No. 135, Guangzhou 510275, China.
| | - Richard M K Saunders
- Division of Ecology & Biodiversity, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
| | - Nan Deng
- Institute of Ecology, Hunan Academy of Forestry, Shaoshannan Road, No. 6581, Changsha 410004, China.
- Hunan Cili Forest Ecosystem State Research Station, Cili 427200, China.
| | - Tao Wan
- Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Science, Liantangxianhu Road, No. 160, Shenzhen 518004, China.
- Sino-Africa Joint Research Centre, Chinese Academy of Science, Moshan, Wuhan 430074, China.
| | - Yingjuan Su
- School of Life Sciences, Sun Yat-Sen University, Xingangxi Road No. 135, Guangzhou 510275, China.
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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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von Aderkas P, Prior NA, Little SA. The Evolution of Sexual Fluids in Gymnosperms From Pollination Drops to Nectar. FRONTIERS IN PLANT SCIENCE 2018; 9:1844. [PMID: 30619413 PMCID: PMC6305574 DOI: 10.3389/fpls.2018.01844] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 11/28/2018] [Indexed: 05/23/2023]
Abstract
A current synthesis of data from modern and fossil plants paints a new picture of sexual fluids, including nectar, as a foundational component of gymnosperm reproductive evolution. We review the morpho-anatomical adaptations, their accompanying secretions, and the functional compounds involved. We discuss two types of secretions: (1) those involved in fertilization fluids produced by gametophytes and archegonia of zooidogamous gymnosperms, i.e., Ginkgo and cycads, and (2) those involved in pollen capture mechanisms (PCMs), i.e., pollination drops. Fertilization fluids provide both liquid in which sperm swim, as well as chemotactic signals that direct sperm to the egg. Such fertilization fluids were probably found among many extinct plants such as ancient cycads and others with swimming sperm, but were subsequently lost upon the evolution of siphonogamy (direct delivery of sperm to the egg by pollen tubes), as found in modern gnetophytes, conifers, and Pinaceae. Pollination drops are discussed in terms of three major types of PCMs and the unique combinations of morphological and biochemical adaptations that define each. These include their amino acids, sugars, calcium, phosphate and proteins. The evolution of PCMs is also discussed with reference to fossil taxa. The plesiomorphic state of extant gymnosperms is a sugar-containing pollination drop functioning as a pollen capture surface, and an in ovulo pollen germination medium. Additionally, these drops are involved in ovule defense, and provide nectar for pollinators. Pollination drops in anemophilous groups have low sugar concentrations that are too low to provide insects with a reward. Instead, they appear to be optimized for defense and microgametophyte development. In insect-pollinated modern Gnetales a variety of tissues produce sexual fluids that bear the biochemical signature of nectar. Complete absence of fluid secretions is restricted to a few, poorly studied modern conifers, and is presumably derived. Aspects of pollination drop dynamics, e.g., regulation of secretion and retraction, are reviewed. Lastly, we discuss pollination drops' control of pollen germination. Large gaps in our current knowledge include the composition of fertilization fluids, the pollination drops of Podocarpaceae, and the overall hydrodynamics of sexual fluids in general.
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Cheng F, Zhao B, Jiang B, Lu Y, Li W, Jin B, Wang L. Constituent analysis and proteomic evaluation of ovular secretions in Ginkgo biloba: not just a pollination medium. PLANT SIGNALING & BEHAVIOR 2018; 13:e1550316. [PMID: 30475662 PMCID: PMC6296353 DOI: 10.1080/15592324.2018.1550316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Pollination drop (PD) is a characteristic feature of major wind-pollinated gymnosperms and plays a vital role during the course of pollination, however, the composition and proteomic profile of PDs in Ginkgo biloba remain unclear. Through inductively coupled plasma mass spectrometry, we detected mineral elements in PDs, including calcium (Ca), sulfur (S), magnesium, boron, and potassium (K), among which S, Ca, and K were found at high levels. The total sugar concentration was approximately 5.908 mg/mL, which accounted for approximately 5.9% (mass ratio) of the PD. The sugars primarily consisted of fructose, glucose, and sucrose, of which the glucose level was highest, accounting for 57.6%, followed by fructose (37.1%) and sucrose (5.3%). We also used FTIR to validate the presence of sugars and proteins in PDs. Further proteomic analysis revealed that the PD contained calmodulin, α-L-arabinofuranosidase, β-D-xylosidase, superoxide dismutase, α-L-arabinosidase, glutathione S-transferase, histones, glycine-rich family protein, methionine synthase, and arabinogalactan, suggesting that proteins present in PDs of G. biloba play a critical role in the defense against external bacteria and facilitate germination and growth of the pollen tube. Our results suggest that PDs are not merely a medium to receive and transport pollen but may also play a more complex biological role in pollination and fertilization.
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Affiliation(s)
- Fangmei Cheng
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- Suqian Academy of Protected Horticultures, Nanjing Agricultural University, Suqian, China
| | - Beibei Zhao
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- Resources & Environment College, Tibet Agriculture & Animal Husbandry University, Linzhi, Tibet
| | - Bei Jiang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
| | - Yan Lu
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- Instrumental Analysis Center, Yangzhou University, Yangzhou, China
| | - Weixing Li
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
| | - Biao Jin
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
| | - Li Wang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- CONTACT Li Wang College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
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Pirone-Davies C, Prior N, von Aderkas P, Smith D, Hardie D, Friedman WE, Mathews S. Insights from the pollination drop proteome and the ovule transcriptome of Cephalotaxus at the time of pollination drop production. ANNALS OF BOTANY 2016; 117:973-84. [PMID: 27045089 PMCID: PMC4866313 DOI: 10.1093/aob/mcw026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 01/08/2016] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Many gymnosperms produce an ovular secretion, the pollination drop, during reproduction. The drops serve as a landing site for pollen, but also contain a suite of ions and organic compounds, including proteins, that suggests diverse roles for the drop during pollination. Proteins in the drops of species of Chamaecyparis, Juniperus, Taxus, Pseudotsuga, Ephedra and Welwitschia are thought to function in the conversion of sugars, defence against pathogens, and pollen growth and development. To better understand gymnosperm pollination biology, the pollination drop proteomes of pollination drops from two species of Cephalotaxus have been characterized and an ovular transcriptome for C. sinensis has been assembled. METHODS Mass spectrometry was used to identify proteins in the pollination drops of Cephalotaxus sinensis and C. koreana RNA-sequencing (RNA-Seq) was employed to assemble a transcriptome and identify transcripts present in the ovules of C. sinensis at the time of pollination drop production. KEY RESULTS About 30 proteins were detected in the pollination drops of both species. Many of these have been detected in the drops of other gymnosperms and probably function in defence, polysaccharide metabolism and pollen tube growth. Other proteins appear to be unique to Cephalotaxus, and their putative functions include starch and callose degradation, among others. Together, the proteins appear either to have been secreted into the drop or to occur there due to breakdown of ovular cells during drop production. Ovular transcripts represent a wide range of gene ontology categories, and some may be involved in drop formation, ovule development and pollen-ovule interactions. CONCLUSIONS The proteome of Cephalotaxus pollination drops shares a number of components with those of other conifers and gnetophytes, including proteins for defence such as chitinases and for carbohydrate modification such as β-galactosidase. Proteins likely to be of intracellular origin, however, form a larger component of drops from Cephalotaxus than expected from studies of other conifers. This is consistent with the observation of nucellar breakdown during drop formation in Cephalotaxus The transcriptome data provide a framework for understanding multiple metabolic processes that occur within the ovule and the pollination drop just before fertilization. They reveal the deep conservation of WUSCHEL expression in ovules and raise questions about whether any of the S-locus transcripts in Cephalotaxus ovules might be involved in pollen-ovule recognition.
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Affiliation(s)
| | | | | | - Derek Smith
- UVic Genome BC Proteomics Centre, Victoria, BC, Canada
| | - Darryl Hardie
- UVic Genome BC Proteomics Centre, Victoria, BC, Canada
| | - William E Friedman
- The Arnold Arboretum of Harvard University, Boston, MA, USA, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Sarah Mathews
- CSIRO, Centre for Australian National Biodiversity Research, Canberra, Australia and
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Li X, Jackson A, Xie M, Wu D, Tsai WC, Zhang S. Proteomic insights into floral biology. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1050-60. [PMID: 26945514 DOI: 10.1016/j.bbapap.2016.02.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 01/25/2016] [Accepted: 02/24/2016] [Indexed: 12/17/2022]
Abstract
The flower is the most important biological structure for ensuring angiosperms reproductive success. Not only does the flower contain critical reproductive organs, but the wide variation in morphology, color, and scent has evolved to entice specialized pollinators, and arguably mankind in many cases, to ensure the successful propagation of its species. Recent proteomic approaches have identified protein candidates related to these flower traits, which has shed light on a number of previously unknown mechanisms underlying these traits. This review article provides a comprehensive overview of the latest advances in proteomic research in floral biology according to the order of flower structure, from corolla to male and female reproductive organs. It summarizes mainstream proteomic methods for plant research and recent improvements on two dimensional gel electrophoresis and gel-free workflows for both peptide level and protein level analysis. The recent advances in sequencing technologies provide a new paradigm for the ever-increasing genome and transcriptome information on many organisms. It is now possible to integrate genomic and transcriptomic data with proteomic results for large-scale protein characterization, so that a global understanding of the complex molecular networks in flower biology can be readily achieved. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock.
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Affiliation(s)
- Xiaobai Li
- Zhejiang Academy of Agricultural Sciences, Shiqiao Road 139, Hangzhou 310021, PR China; International Atomic Energy Agency Collaborating Center, Zhejiang University, Hangzhou 310029, PR China.
| | | | - Ming Xie
- Zhejiang Academy of Agricultural Sciences, Shiqiao Road 139, Hangzhou 310021, PR China.
| | - Dianxing Wu
- International Atomic Energy Agency Collaborating Center, Zhejiang University, Hangzhou 310029, PR China
| | - Wen-Chieh Tsai
- Institute of Tropical Plant Sciences, National Cheng Kung University, Tainan 701, Taiwan
| | - Sheng Zhang
- Proteomics and Mass Spectrometry Facility, Cornell University, New York 14853, USA
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Liu Y, Joly V, Dorion S, Rivoal J, Matton DP. The Plant Ovule Secretome: A Different View toward Pollen-Pistil Interactions. J Proteome Res 2015; 14:4763-75. [PMID: 26387803 DOI: 10.1021/acs.jproteome.5b00618] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During plant sexual reproduction, continuous exchange of signals between the pollen and the pistil (stigma, style, and ovary) plays important roles in pollen recognition and selection, establishing breeding barriers and, ultimately, leading to optimal seed set. After navigating through the stigma and the style, pollen tubes (PTs) reach their final destination, the ovule. This ultimate step is also regulated by numerous signals emanating from the embryo sac (ES) of the ovule. These signals encompass a wide variety of molecules, but species-specificity of the pollen-ovule interaction relies mainly on secreted proteins and their receptors. Isolation of candidate genes involved in pollen-pistil interactions has mainly relied on transcriptomic approaches, overlooking potential post-transcriptional regulation. To address this issue, ovule exudates were collected from the wild potato species Solanum chacoense using a tissue-free gravity-extraction method (tf-GEM). Combined RNA-seq and mass spectrometry-based proteomics led to the identification of 305 secreted proteins, of which 58% were ovule-specific. Comparative analyses using mature ovules (attracting PTs) and immature ovules (not attracting PTs) revealed that the last maturation step of ES development affected almost half of the ovule secretome. Of 128 upregulated proteins in anthesis stage, 106 were not regulated at the mRNA level, emphasizing the importance of post-transcriptional regulation in reproductive development.
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Affiliation(s)
- Yang Liu
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal , 4101 rue Sherbrooke est, Montréal, Québec H1X 2B2, Canada
| | - Valentin Joly
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal , 4101 rue Sherbrooke est, Montréal, Québec H1X 2B2, Canada
| | - Sonia Dorion
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal , 4101 rue Sherbrooke est, Montréal, Québec H1X 2B2, Canada
| | - Jean Rivoal
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal , 4101 rue Sherbrooke est, Montréal, Québec H1X 2B2, Canada
| | - Daniel P Matton
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal , 4101 rue Sherbrooke est, Montréal, Québec H1X 2B2, Canada
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