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Wu YN, Lu JY, Li S, Zhang Y. Are vacuolar dynamics crucial factors for plant cell division and differentiation? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 344:112090. [PMID: 38636812 DOI: 10.1016/j.plantsci.2024.112090] [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: 02/14/2024] [Revised: 04/03/2024] [Accepted: 04/10/2024] [Indexed: 04/20/2024]
Abstract
Vacuoles are the largest membrane-bound organelles in plant cells, critical for development and environmental responses. Vacuolar dynamics indicate reversible changes of vacuoles in morphology, size, or numbers. In this review, we summarize current understandings of vacuolar dynamics in different types of plant cells, biological processes associated with vacuolar dynamics, and regulators controlling vacuolar dynamics. Specifically, we point out the possibility that vacuolar dynamics play key roles in cell division and differentiation, which are controlled by the nucleus. Finally, we propose three routes through which vacuolar dynamics actively participate in nucleus-controlled cellular activities.
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Affiliation(s)
- Ya-Nan Wu
- Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jin-Yu Lu
- Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Sha Li
- College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Yan Zhang
- Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China.
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2
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Rauf A, Wang A, Li Y, Lian Z, Wei S, Jabbar K, Wisal M, Khan I, Khalid M, Li J. The male germ unit association is independently regulated of GUM in Arabidopsis thaliana. PLANT DIRECT 2024; 8:e624. [PMID: 39076347 PMCID: PMC11286290 DOI: 10.1002/pld3.624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/17/2024] [Accepted: 07/06/2024] [Indexed: 07/31/2024]
Abstract
Cytoplasmic projections (CPs) formed by the generative and sperm cells link the male gametes with the vegetative cell (VC) nucleus, which are required to build the male germ unit (MGU) assemblage in the angiosperm pollen grain. As molecular and genetic controls underlying CP development and formation of the MGU are unknown, it was hypothesized that physical association between germ cells and the VC nucleus might be lost in germ unit malformed (gum) mutants or in those which either block generative cell (GC) division or that additionally prevent gamete differentiation. In vivo, analysis of marked cellular components demonstrated a linkage of sperm cells (SCs) and the VC nucleus in gum mutant alleles despite their increased physical separation. Similarly, for several independent classes of bicellular pollen mutants, undivided GCs were associated with the VC nucleus like GCs in wild-type pollen. We conclude that the early formation of GC CPs to establish the MGU is regulated independently of DUO1-DAZ1 and DUO3 transcription factors as well as cyclin-dependent kinase function (CDKA;1). As the absence of cytoplasmic protrusion was expected in the gum mutants in Arabidopsis, early histological studies reported temporal disappearance of cytoplasmic protrusion in several organisms. Our findings demonstrated the striking importance of live imaging to verify the broad conservation of the persistent MGU contact in all the angiosperms and its important role in successful double fertilization.
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Affiliation(s)
- Abdur Rauf
- National Key Laboratory for Tropical Crop Breeding, Tropical Crop Genetic Resources Institute Chinese Academy of Tropical Agricultural Sciences Sanya/Haikou Hainan China
- Garden Campus, Department of Botany Abdul Wali Khan University Mardan KP Pakistan
- Department of Genetic and Genome Biology University of Leicester UK
- Hainan Banana Healthy Seedling Propagation Engineering Research Center, Haikou Experimental Station Chinese Academy of Tropical Agricultural Sciences Haikou Hainan China
| | - Anbang Wang
- National Key Laboratory for Tropical Crop Breeding, Tropical Crop Genetic Resources Institute Chinese Academy of Tropical Agricultural Sciences Sanya/Haikou Hainan China
| | - Yujia Li
- National Key Laboratory for Tropical Crop Breeding, Tropical Crop Genetic Resources Institute Chinese Academy of Tropical Agricultural Sciences Sanya/Haikou Hainan China
| | - Zhihao Lian
- National Key Laboratory for Tropical Crop Breeding, Tropical Crop Genetic Resources Institute Chinese Academy of Tropical Agricultural Sciences Sanya/Haikou Hainan China
| | - Shouxing Wei
- National Key Laboratory for Tropical Crop Breeding, Tropical Crop Genetic Resources Institute Chinese Academy of Tropical Agricultural Sciences Sanya/Haikou Hainan China
| | | | - Muhammad Wisal
- Garden Campus, Department of Botany Abdul Wali Khan University Mardan KP Pakistan
| | - Ikramullah Khan
- Garden Campus, Department of Botany Abdul Wali Khan University Mardan KP Pakistan
| | - Muhammad Khalid
- Department of Biology, College of Science, Mathematics and Technology Wenzhou-Kean University Wenzhou China
| | - Jingyang Li
- National Key Laboratory for Tropical Crop Breeding, Tropical Crop Genetic Resources Institute Chinese Academy of Tropical Agricultural Sciences Sanya/Haikou Hainan China
- Hainan Banana Healthy Seedling Propagation Engineering Research Center, Haikou Experimental Station Chinese Academy of Tropical Agricultural Sciences Haikou Hainan China
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3
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Sze H, Klodová B, Ward JM, Harper JF, Palanivelu R, Johnson MA, Honys D. A wave of specific transcript and protein accumulation accompanies pollen dehydration. PLANT PHYSIOLOGY 2024; 195:1775-1795. [PMID: 38530638 DOI: 10.1093/plphys/kiae177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/13/2023] [Accepted: 01/08/2024] [Indexed: 03/28/2024]
Abstract
In flowering plants, male gametes are immotile and carried by dry pollen grains to the female organ. Dehydrated pollen is thought to withstand abiotic stress when grains are dispersed from the anther to the pistil, after which sperm cells are delivered via pollen tube growth for fertilization and seed set. Yet, the underlying molecular changes accompanying dehydration and the impact on pollen development are poorly understood. To gain a systems perspective, we analyzed published transcriptomes and proteomes of developing Arabidopsis thaliana pollen. Waves of transcripts are evident as microspores develop to bicellular, tricellular, and mature pollen. Between the "early"- and "late"-pollen-expressed genes, an unrecognized cluster of transcripts accumulated, including those encoding late-embryogenesis abundant (LEA), desiccation-related protein, transporters, lipid-droplet associated proteins, pectin modifiers, cysteine-rich proteins, and mRNA-binding proteins. Results suggest dehydration onset initiates after bicellular pollen is formed. Proteins accumulating in mature pollen like ribosomal proteins, initiation factors, and chaperones are likely components of mRNA-protein condensates resembling "stress" granules. Our analysis has revealed many new transcripts and proteins that accompany dehydration in developing pollen. Together with published functional studies, our results point to multiple processes, including (1) protect developing pollen from hyperosmotic stress, (2) remodel the endomembrane system and walls, (3) maintain energy metabolism, (4) stabilize presynthesized mRNA and proteins in condensates of dry pollen, and (5) equip pollen for compatibility determination at the stigma and for recovery at rehydration. These findings offer novel models and molecular candidates to further determine the mechanistic basis of dehydration and desiccation tolerance in plants.
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Affiliation(s)
- Heven Sze
- Department Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Božena Klodová
- Institute of Experimental Botany of the Czech Academy of Sciences, 165 02 Prague 6, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Praha 2, 128 00, Czech Republic
| | - John M Ward
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN 55108, USA
| | - Jeffrey F Harper
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA
| | | | - Mark A Johnson
- Department of Molecular, Cellular Biology, and Biochemistry, Brown University, Providence, RI 02912, USA
| | - David Honys
- Institute of Experimental Botany of the Czech Academy of Sciences, 165 02 Prague 6, Czech Republic
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4
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Faltus M, Domkářová J, Svoboda P, Horáčková V, Nesvadba V, Klička V, Ptáček J, Bilavcik A, Zamecnik J. Analysis of Thermal Characteristics of Potato and Hop Pollen for Their Cryopreservation and Cross-Breeding. PLANTS (BASEL, SWITZERLAND) 2024; 13:1578. [PMID: 38891386 PMCID: PMC11174463 DOI: 10.3390/plants13111578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024]
Abstract
This study investigated the thermal properties of potato and hop pollen for cryopreservation and subsequent cross-breeding. Phase transitions and frozen water content in selected pollen samples were measured using a differential scanning calorimeter (DSC). Unlike hop pollen, potato pollen showed high variability in thermal properties and water content. Three specific types of pollen samples based on their thermal characteristics and water content were distinguished by DSC in potato: (1) 'glassy', with a water content lower than 0.21 g water per g dry matter; (2) 'transient', with a water content between 0.27 and 0.34 g of water per g of dry matter; (3) 'frozen', with a water content higher than 0.34 g of water per g of dry matter. Only the 'glassy' pollen samples with a low water content showed suitable properties for its long-term storage using cryopreservation in potato and hops. Cryopreservation of pollen did not significantly reduce its viability, and cryopreserved pollen was successfully used to produce both potato and hop hybrids. The results indicate that cryopreservation is a feasible technique for the preservation and utilization of pollen of these crops in the breeding process.
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Affiliation(s)
- Milos Faltus
- Crop Research Institute, Drnovská 507, CZ161 06 Prague, Czech Republic; (A.B.); (J.Z.)
| | - Jaroslava Domkářová
- Potato Research Institute, Dobrovského 2366, CZ580 01 Havlickuv Brod, Czech Republic; (J.D.); (V.H.); (J.P.)
| | - Petr Svoboda
- Hop Research Institute, Kadaňská 2525, CZ438 01 Zatec, Czech Republic; (P.S.); (V.N.)
| | - Vendulka Horáčková
- Potato Research Institute, Dobrovského 2366, CZ580 01 Havlickuv Brod, Czech Republic; (J.D.); (V.H.); (J.P.)
| | - Vladimír Nesvadba
- Hop Research Institute, Kadaňská 2525, CZ438 01 Zatec, Czech Republic; (P.S.); (V.N.)
| | | | - Jiří Ptáček
- Potato Research Institute, Dobrovského 2366, CZ580 01 Havlickuv Brod, Czech Republic; (J.D.); (V.H.); (J.P.)
| | - Alois Bilavcik
- Crop Research Institute, Drnovská 507, CZ161 06 Prague, Czech Republic; (A.B.); (J.Z.)
| | - Jiri Zamecnik
- Crop Research Institute, Drnovská 507, CZ161 06 Prague, Czech Republic; (A.B.); (J.Z.)
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Huang C, Kurotani KI, Tabata R, Mitsuda N, Sugita R, Tanoi K, Notaguchi M. Nicotiana benthamiana XYLEM CYSTEINE PROTEASE genes facilitate tracheary element formation in interfamily grafting. HORTICULTURE RESEARCH 2023; 10:uhad072. [PMID: 37303612 PMCID: PMC10251136 DOI: 10.1093/hr/uhad072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/08/2023] [Indexed: 06/13/2023]
Abstract
Grafting is a plant propagation technique widely used in agriculture. A recent discovery of the capability of interfamily grafting in Nicotiana has expanded the potential combinations of grafting. In this study, we showed that xylem connection is essential for the achievement of interfamily grafting and investigated the molecular basis of xylem formation at the graft junction. Transcriptome and gene network analyses revealed gene modules for tracheary element (TE) formation during grafting that include genes associated with xylem cell differentiation and immune response. The reliability of the drawn network was validated by examining the role of the Nicotiana benthamiana XYLEM CYSTEINE PROTEASE (NbXCP) genes in TE formation during interfamily grafting. Promoter activities of NbXCP1 and NbXCP2 genes were found in differentiating TE cells in the stem and callus tissues at the graft junction. Analysis of a Nbxcp1;Nbxcp2 loss-of-function mutant indicated that NbXCPs control the timing of de novo TE formation at the graft junction. Moreover, grafts of the NbXCP1 overexpressor increased the scion growth rate as well as the fruit size. Thus, we identified gene modules for TE formation at the graft boundary and demonstrated potential ways to enhance Nicotiana interfamily grafting.
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Affiliation(s)
- Chaokun Huang
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Ken-ichi Kurotani
- Bioscience and Biotechnology Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Ryo Tabata
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Nobutaka Mitsuda
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
| | - Ryohei Sugita
- Isotope Facility for Agricultural Education and Research, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Radioisotope Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Keitaro Tanoi
- Isotope Facility for Agricultural Education and Research, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Felts AM, Pokharel B, Yahya D, Aziz AN. Whole-genomic DNA amplifications from individually isolated sweet sorghum microspores. APPLICATIONS IN PLANT SCIENCES 2022; 10:e11501. [PMID: 36518943 PMCID: PMC9742829 DOI: 10.1002/aps3.11501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/12/2022] [Indexed: 06/17/2023]
Abstract
PREMISE Sorghum is a multi-use crop, the efficient breeding of which requires the development of new genetic tools. One such tool could be the genetic assessment of free microspores, which are released just after the tetrad stage of pollen development. Microspores are ideal for DNA isolation as they have underdeveloped cell walls and can be readily lysed as natural protoplasts. METHODS Four cultivars of Sorghum bicolor ('Achi Turi', 'Dale', 'Local', and 'Topper 76-6') were grown in a greenhouse until flowering (7.7-11.5 cm flag leaf internode length), after which 30 immature microspores were isolated from each line. Plant height, time to flowering, boot radius, and spikelet maturation were recorded for each cultivar. The exine development of the microspores was observed under an inverted Nikon microscope, and those with underdeveloped exine were subjected to whole-genome amplification and sequencing. RESULTS Microspores in the early uninucleate to early binucleate stages had underdeveloped exine, and were therefore ideal for DNA extraction. High-quality DNA was obtained from these single-cell gametophytes. The average DNA concentration was 2902 ng/µL, with fragment sizes comparable to those obtained from leaf tissue extractions. DISCUSSION Harvesting panicles with immature microspores means the entire gametic population is accessible for DNA analyses. This is the first amplification of whole-genome DNA fragments from sorghum single-cell microspores isolated during gametogenesis.
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Affiliation(s)
- Aron M. Felts
- Department of Agricultural and Environmental SciencesTennessee State University3500 John Merritt Blvd.NashvilleTennessee37209USA
| | - Bharat Pokharel
- Department of Agricultural and Environmental SciencesTennessee State University3500 John Merritt Blvd.NashvilleTennessee37209USA
| | - Dilovan Yahya
- Department of Agricultural and Environmental SciencesTennessee State University3500 John Merritt Blvd.NashvilleTennessee37209USA
| | - Ahmad N. Aziz
- Department of Agricultural and Environmental SciencesTennessee State University3500 John Merritt Blvd.NashvilleTennessee37209USA
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Jiang YT, Zheng JX, Li RH, Wang YC, Shi J, Ferjani A, Lin WH. Tonoplast proton pumps regulate nuclear spacing of female gametophytes via mediating polar auxin transport in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2022; 13:1006735. [PMID: 36176689 PMCID: PMC9513470 DOI: 10.3389/fpls.2022.1006735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 08/26/2022] [Indexed: 06/16/2023]
Abstract
The vacuole is an important organelle with multiple functions in plants, and the tonoplast that wraps the vacuole also plays essential roles in intracellular trafficking and ion homeostasis. Previous studies found that tonoplast proton pumps regulate embryo development and morphogenesis through their effects on vacuole biogenesis and distribution, as well as polar auxin transport and concomitant auxin gradient. However, the precise roles of the tonoplast proton pumps in gametophyte development remain unclear. Here we demonstrated that the lack of two types of tonoplast proton pumps or the absence of V-ATPase alone leads to abnormal development and nuclear localization of female gametophyte (FG), and slowed endosperm nuclei division after fertilization of the central cell. We further revealed that V-ATPase regulates auxin levels in ovules through coordinating the content and localization of PIN-FORMED 1 (PIN1) protein, hence influencing nuclear spacing between centra cell and egg cell, and subsequent endosperm development. Collectively, our findings revealed a crucial role of V-ATPase in auxin-mediated FG development in Arabidopsis and expanded our understanding of the functions of tonoplast proton pumps in seed plants reproductive development.
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Affiliation(s)
- Yu-Tong Jiang
- Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, The Joint International Research, Shanghai Jiao Tong University, Shanghai, China
| | - Ji-Xuan Zheng
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai, China
| | - Rong-Han Li
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai, China
| | - Yu-Chen Wang
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai, China
| | - Jianxin Shi
- Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, The Joint International Research, Shanghai Jiao Tong University, Shanghai, China
| | - Ali Ferjani
- Department of Biology, Tokyo Gakugei University, Koganei, Japan
| | - Wen-Hui Lin
- Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, The Joint International Research, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai, China
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Kaur D, Moreira D, Coimbra S, Showalter AM. Hydroxyproline- O-Galactosyltransferases Synthesizing Type II Arabinogalactans Are Essential for Male Gametophytic Development in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2022; 13:935413. [PMID: 35774810 PMCID: PMC9237623 DOI: 10.3389/fpls.2022.935413] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 05/17/2022] [Indexed: 05/25/2023]
Abstract
In flowering plants, male reproductive function is determined by successful development and performance of stamens, pollen grains, and pollen tubes. Despite the crucial role of highly glycosylated arabinogalactan-proteins (AGPs) in male gamete formation, pollen grain, and pollen tube cell walls, the underlying mechanisms defining these functions of AGPs have remained elusive. Eight partially redundant Hyp-galactosyltransferases (named GALT2-GALT9) genes/enzymes are known to initiate Hyp-O-galactosylation for Hyp-arabinogalactan (AG) production in Arabidopsis thaliana. To assess the contributions of these Hyp-AGs to male reproductive function, we used a galt2galt5galt7galt8galt9 quintuple Hyp-GALT mutant for this study. Both anther size and pollen viability were compromised in the quintuple mutants. Defects in male gametogenesis were observed in later stages of maturing microspores after meiosis, accompanied by membrane blebbing and numerous lytic vacuoles. Cytological and ultramicroscopic observations revealed that pollen exine reticulate architecture and intine layer development were affected such that non-viable collapsed mature pollen grains were produced, which were devoid of cell content and nuclei, with virtually no intine. AGP immunolabeling demonstrated alterations in cell wall architecture of the anther, pollen grains, and pollen tube. Specifically, the LM2 monoclonal antibody (which recognized β-GlcA epitopes on AGPs) showed a weak signal for the endothecium, microspores, and pollen tube apex. Pollen tube tips also displayed excessive callose deposition. Interestingly, expression patterns of pollen-specific AGPs, namely AGP6, AGP11, AGP23, and AGP40, were determined to be higher in the quintuple mutants. Taken together, our data illustrate the importance of type-II AGs in male reproductive function for successful fertilization.
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Affiliation(s)
- Dasmeet Kaur
- Department of Environmental & Plant Biology, Ohio University, Athens, OH, United States
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, United States
| | - Diana Moreira
- Departamento de Biología, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
- LAQV Requimte, Sustainable Chemistry, Universidade do Porto, Porto, Portugal
| | - Sílvia Coimbra
- Departamento de Biología, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
- LAQV Requimte, Sustainable Chemistry, Universidade do Porto, Porto, Portugal
| | - Allan M. Showalter
- Department of Environmental & Plant Biology, Ohio University, Athens, OH, United States
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, United States
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9
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The True Identity of the “Second Pollen Morphology” of Camellia oleifera—Stomium Cells. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8040347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Previous studies on Camellia oleifera pollen morphology have indicated dual morphologies, defined as “dimorphism”. However, they were limited to morphological studies at the end of final development and did not elucidate the origin, structure, and function of the second pollen morphology (striate pollen). In this study, the differences between the two “pollen” types were compared by paraffin sections, scanning electron microscopy (SEM), fluorescence microscopy, and in vitro germination. The results clearly showed that the second pollen type was formed by stomium cells of the anther, which is responsible for anther dehiscence. The nucleus and vesicles of the stomium cell were specifically distributed during anther development, which may be related to the formation of the septum, pollen dispersal activity, and the increase in stomium cell count; at the microscopic level, the stomium cell mainly consisted of the cell wall, large vesicles, and nucleus. The large vesicles facilitate the rapid dehydration of stomium cells under suitable conditions for anther dehiscence. Furthermore, studies on other species of the genus Camellia have suggested that the second type of pollen morphology is pseudopollen, which is capable of partaking in deceptive pollination. The present study refuted this theory and suggested that the pseudopollen are stomium cells, whose structure relates to their function. These results provide the basis for further research on C. oleifera pollen physiology toward the improvement of pollination rates with agricultural practices or breeding interventions.
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Roeder AHK, Otegui MS, Dixit R, Anderson CT, Faulkner C, Zhang Y, Harrison MJ, Kirchhelle C, Goshima G, Coate JE, Doyle JJ, Hamant O, Sugimoto K, Dolan L, Meyer H, Ehrhardt DW, Boudaoud A, Messina C. Fifteen compelling open questions in plant cell biology. THE PLANT CELL 2022; 34:72-102. [PMID: 34529074 PMCID: PMC8774073 DOI: 10.1093/plcell/koab225] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/02/2021] [Indexed: 05/02/2023]
Abstract
As scientists, we are at least as excited about the open questions-the things we do not know-as the discoveries. Here, we asked 15 experts to describe the most compelling open questions in plant cell biology. These are their questions: How are organelle identity, domains, and boundaries maintained under the continuous flux of vesicle trafficking and membrane remodeling? Is the plant cortical microtubule cytoskeleton a mechanosensory apparatus? How are the cellular pathways of cell wall synthesis, assembly, modification, and integrity sensing linked in plants? Why do plasmodesmata open and close? Is there retrograde signaling from vacuoles to the nucleus? How do root cells accommodate fungal endosymbionts? What is the role of cell edges in plant morphogenesis? How is the cell division site determined? What are the emergent effects of polyploidy on the biology of the cell, and how are any such "rules" conditioned by cell type? Can mechanical forces trigger new cell fates in plants? How does a single differentiated somatic cell reprogram and gain pluripotency? How does polarity develop de-novo in isolated plant cells? What is the spectrum of cellular functions for membraneless organelles and intrinsically disordered proteins? How do plants deal with internal noise? How does order emerge in cells and propagate to organs and organisms from complex dynamical processes? We hope you find the discussions of these questions thought provoking and inspiring.
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Affiliation(s)
| | - Marisa S Otegui
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Wisconsin 53706, USA
| | - Ram Dixit
- Department of Biology and Center for Engineering Mechanobiology, Washington University in St Louis, Missouri 63130, USA
| | - Charles T Anderson
- Department of Biology and Center for Lignocellulose Structure and Formation, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Christine Faulkner
- Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | | | - Charlotte Kirchhelle
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, Lyon Cedex 07, France
| | - Gohta Goshima
- Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Jeremy E Coate
- Department of Biology, Reed College, Portland, Oregon 97202, USA
| | - Jeff J Doyle
- School of Integrative Plant Science, Section of Plant Biology and Section of Plant Breeding and Genetics, Cornell University, Ithaca, New York 14853, USA
| | - Olivier Hamant
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCBL, INRAE, CNRS, Lyon Cedex 07, France
| | - Keiko Sugimoto
- Center for Sustainable Resource Science, RIKEN, Kanagawa 230-0045, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Liam Dolan
- Gregor Mendel Institute of Molecular Plant Biology GmbH, Vienna 1030, Austria
| | - Heather Meyer
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, USA
| | - David W Ehrhardt
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, USA
| | - Arezki Boudaoud
- LadHyX, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau Cedex 91128 France
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11
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Duckney P, Kroon JT, Dixon MR, Hawkins TJ, Deeks MJ, Hussey PJ. NETWORKED2-subfamily proteins regulate the cortical actin cytoskeleton of growing pollen tubes and polarised pollen tube growth. THE NEW PHYTOLOGIST 2021; 231:152-164. [PMID: 33864269 DOI: 10.1111/nph.17391] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
We have recently characterised NET2A as a pollen-specific actin-binding protein that binds F-actin at the plasma membrane of growing pollen tubes. However, the role of NET2 proteins in pollen development and fertilisation have yet to be elucidated. To further characterise the role of Arabidopsis NET2 proteins in pollen development and fertilisation, we analysed the subcellular localisation of NET2A over the course of pollen grain development and investigated the role of the NET2 family using net2 loss-of-function mutants. We observed NET2A to localise to the F-actin cytoskeleton in developing pollen grains as it underwent striking structural reorganisations at specific stages of development and during germination and pollen tube growth. Furthermore, net2 loss-of-function mutants exhibited striking morphological defects in the early stages of pollen tube growth, arising from frequent changes to pollen tube growth trajectory. We observed defects in the cortical actin cytoskeleton and actin-driven subcellular processes in net2 mutant pollen tubes. We demonstrate that NET2 proteins are essential for normal actin-driven pollen development highlighting an important role for the NET2 family members in regulating pollen tube growth during fertilisation.
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Affiliation(s)
- Patrick Duckney
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Johan T Kroon
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Martin R Dixon
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Timothy J Hawkins
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Michael J Deeks
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Patrick J Hussey
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
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12
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Rui Q, Tan X, Liu F, Li Y, Liu X, Li B, Wang J, Yang H, Qiao L, Li T, Fang S, Gao R, Wang W, Bednarek SY, Bao Y. Syntaxin of plants31 (SYP31) and SYP32 is essential for Golgi morphology maintenance and pollen development. PLANT PHYSIOLOGY 2021; 186:330-343. [PMID: 33576796 PMCID: PMC8154079 DOI: 10.1093/plphys/kiab049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 01/19/2021] [Indexed: 05/27/2023]
Abstract
Pollen development is a key process for the sexual reproduction of angiosperms. The Golgi plays a critical role in pollen development via the synthesis and transport of cell wall materials. However, little is known about the molecular mechanisms underlying the maintenance of Golgi integrity in plants. In Arabidopsis thaliana, syntaxin of plants (SYP) 3 family proteins SYP31 and SYP32 are the only two Golgi-localized Qa-soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs) with unknown endogenous functions. Here, we demonstrate the roles of SYP31 and SYP32 in modulating Golgi morphology and pollen development. Two independent lines of syp31/+ syp32/+ double mutants were male gametophytic lethal; the zero transmission rate of syp31 syp32 mutations was restored to largely normal levels by pSYP32:SYP32 but not pSYP32:SYP31 transgenes, indicating their functional differences in pollen development. The initial arrest of syp31 syp32 pollen occurred during the transition from the microspore to the bicellular stage, where cell plate formation in pollen mitosis I (PMI) and deposition of intine were abnormal. In syp31 syp32 pollen, the number and length of Golgi cisterna were significantly reduced, accompanied by many surrounding vesicles, which could be largely attributed to defects in anterograde and retrograde trafficking routes. SYP31 and SYP32 directly interacted with COG3, a subunit of the conserved oligomeric Golgi (COG) complex and were responsible for its Golgi localization, providing an underlying mechanism for SYP31/32 function in intra-Golgi trafficking. We propose that SYP31 and SYP32 play partially redundant roles in pollen development by modulating protein trafficking and Golgi structure.
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Affiliation(s)
- Qingchen Rui
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Xiaoyun Tan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Feng Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Yanbin Li
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Xin Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Bingxuan Li
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Junxia Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Huiting Yang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Lixin Qiao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Tingting Li
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Shuo Fang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Rongrong Gao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Wang Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Sebastian Y Bednarek
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Yiqun Bao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China
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13
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Liu F, Li JP, Li LS, Liu Q, Li SW, Song ML, Li S, Zhang Y. The canonical α-SNAP is essential for gametophytic development in Arabidopsis. PLoS Genet 2021; 17:e1009505. [PMID: 33886546 PMCID: PMC8096068 DOI: 10.1371/journal.pgen.1009505] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 05/04/2021] [Accepted: 03/24/2021] [Indexed: 12/26/2022] Open
Abstract
The development of male and female gametophytes is a pre-requisite for successful reproduction of angiosperms. Factors mediating vesicular trafficking are among the key regulators controlling gametophytic development. Fusion between vesicles and target membranes requires the assembly of a fusogenic soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs) complex, whose disassembly in turn ensures the recycle of individual SNARE components. The disassembly of post-fusion SNARE complexes is controlled by the AAA+ ATPase N-ethylmaleimide-sensitive factor (Sec18/NSF) and soluble NSF attachment protein (Sec17/α-SNAP) in yeast and metazoans. Although non-canonical α-SNAPs have been functionally characterized in soybeans, the biological function of canonical α-SNAPs has yet to be demonstrated in plants. We report here that the canonical α-SNAP in Arabidopsis is essential for male and female gametophytic development. Functional loss of the canonical α-SNAP in Arabidopsis results in gametophytic lethality by arresting the first mitosis during gametogenesis. We further show that Arabidopsis α-SNAP encodes two isoforms due to alternative splicing. Both isoforms interact with the Arabidopsis homolog of NSF whereas have distinct subcellular localizations. The presence of similar alternative splicing of human α-SNAP indicates that functional distinction of two α-SNAP isoforms is evolutionarily conserved.
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Affiliation(s)
- Fei Liu
- Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
| | - Ji-Peng Li
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Lu-Shen Li
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Qi Liu
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Shan-Wei Li
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Ming-Lei Song
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Sha Li
- Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin, China
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- * E-mail: (SL); (YZ)
| | - Yan Zhang
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- * E-mail: (SL); (YZ)
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14
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Ma T, Li E, Li LS, Li S, Zhang Y. The Arabidopsis R-SNARE protein YKT61 is essential for gametophyte development. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:676-694. [PMID: 32918784 DOI: 10.1111/jipb.13017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/12/2020] [Indexed: 05/23/2023]
Abstract
Gametophyte development is a pre-requisite for plant reproduction and seed yield; therefore, studies of gametophyte development help us understand fundamental biological questions and have potential applications in agriculture. The biogenesis and dynamics of endomembrane compartments are critical for cell survival, and their regulatory mechanisms are just beginning to be revealed. Here, we report that the Arabidopsis thaliana SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) protein YKT61 is essential for both male and female gametogenesis. By using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-based genome editing, we demonstrated that male and female gametophytes carrying YKT61 loss-of-function alleles do not survive. Specifically, loss of YKT61 function resulted in the arrest of male gametophytic development at pollen mitosis I and the degeneration of female gametophytes. A three-base-pair deletion in YKT61 in the ykt61-3 mutant resulted in a single-amino acid deletion in the longin domain of YKT61; the resulting mutant protein does not interact with multiple SNAREs and showed substantially reduced membrane association, suggesting that the N-terminal longin domain of YKT61 plays multiple roles in its function. This study demonstrates that Arabidopsis YKT61 is essential for male and female gametogenesis and sets an example for functional characterization of essential genes with the combination of Cas9-mediated editing and expression from a Cas9-resistant transgene.
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Affiliation(s)
- Ting Ma
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - En Li
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Lu-Shen Li
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Sha Li
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Yan Zhang
- State Key laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
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15
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Jeong J, Park S, Im JH, Yi H. Genome-wide identification of GH3 genes in Brassica oleracea and identification of a promoter region for anther-specific expression of a GH3 gene. BMC Genomics 2021; 22:22. [PMID: 33407107 PMCID: PMC7789250 DOI: 10.1186/s12864-020-07345-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/22/2020] [Indexed: 01/07/2023] Open
Abstract
Background The Gretchen Hagen 3 (GH3) genes encode acyl acid amido synthetases, many of which have been shown to modulate the amount of active plant hormones or their precursors. GH3 genes, especially Group III subgroup 6 GH3 genes, and their expression patterns in economically important B. oleracea var. oleracea have not been systematically identified. Results As a first step to understand regulation and molecular functions of Group III subgroup 6 GH3 genes, 34 GH3 genes including four subgroup 6 genes were identified in B. oleracea var. oleracea. Synteny found around subgroup 6 GH3 genes in B. oleracea var. oleracea and Arabidopsis thaliana indicated that these genes are evolutionarily related. Although expression of four subgroup 6 GH3 genes in B. oleracea var. oleracea is not induced by auxin, gibberellic acid, or jasmonic acid, the genes show different organ-dependent expression patterns. Among subgroup 6 GH3 genes in B. oleracea var. oleracea, only BoGH3.13–1 is expressed in anthers when microspores, polarized microspores, and bicellular pollens are present, similar to two out of four syntenic A. thaliana subgroup 6 GH3 genes. Detailed analyses of promoter activities further showed that BoGH3.13–1 is expressed in tapetal cells and pollens in anther, and also expressed in leaf primordia and floral abscission zones. Conclusions Sixty-two base pairs (bp) region (− 340 ~ − 279 bp upstream from start codon) and about 450 bp region (− 1489 to − 1017 bp) in BoGH3.13–1 promoter are important for expressions in anther and expressions in leaf primordia and floral abscission zones, respectively. The identified anther-specific promoter region can be used to develop male sterile transgenic Brassica plants. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-020-07345-9.
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Affiliation(s)
- Jiseong Jeong
- Department of Biological Sciences, College of Biological Science and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Sunhee Park
- Department of Biological Sciences, College of Biological Science and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jeong Hui Im
- Department of Biological Sciences, College of Biological Science and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Hankuil Yi
- Department of Biological Sciences, College of Biological Science and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea.
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16
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Akita K, Takagi T, Kobayashi K, Kuchitsu K, Kuroiwa T, Nagata N. Ultrastructural characterization of microlipophagy induced by the interaction of vacuoles and lipid bodies around generative and sperm cells in Arabidopsis pollen. PROTOPLASMA 2021; 258:129-138. [PMID: 32968871 PMCID: PMC7782417 DOI: 10.1007/s00709-020-01557-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/08/2020] [Indexed: 05/14/2023]
Abstract
During pollen maturation, various organelles change their distribution and function during development as male gametophytes. We analyzed the behavior of lipid bodies and vacuoles involved in lipophagy in Arabidopsis pollen using serial section SEM and conventional TEM. At the bicellular pollen stage, lipid bodies in the vegetative cells lined up at the surface of the generative cell. Vacuoles then tightly attached, drew in, and degraded the lipid bodies and eventually occupied the space of the lipid bodies. Degradation of lipid began before transfer of the entire contents of the lipid body. At the tricellular stage, vacuoles instead of lipid bodies surrounded the sperm cells. The degradation of lipid bodies is morphologically considered microautophagy. The atg2-1 Arabidopsis mutant is deficient in one autophagy-related gene (ATG). In this mutant, the assembly of vacuoles around sperm cells was sparser than that in wild-type pollen. The deficiency of ATG2 likely prevents or slows lipid degradation, although it does not prevent contact between organelles. These results demonstrate the involvement of microlipophagy in the pollen development of Arabidopsis.
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Affiliation(s)
- Kae Akita
- Department of Chemical Biological Sciences, Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, Japan
| | - Tomoko Takagi
- Department of Chemical Biological Sciences, Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, Japan
| | - Keiko Kobayashi
- Department of Chemical Biological Sciences, Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, Japan
| | - Kazuyuki Kuchitsu
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba, Japan
| | - Tsuneyoshi Kuroiwa
- Department of Chemical Biological Sciences, Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, Japan
| | - Noriko Nagata
- Department of Chemical Biological Sciences, Faculty of Science, Japan Women's University, Bunkyo-ku, Tokyo, Japan.
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17
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Rocha DM, Vanzela ALL, Mariath JEA. Are unusual ultrastructural features occurring in the pollen endomembrane system of Cyperaceae and other angiosperms? Cell Biol Int 2020; 44:2065-2074. [PMID: 32609911 DOI: 10.1002/cbin.11415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/16/2020] [Accepted: 06/28/2020] [Indexed: 11/06/2022]
Abstract
Cyperaceae representatives present peculiar microsporogenesis and microgametogenesis, which raises the question of how regular the sedge pollen is. In order to answer this question, preanthesis pollen grains of Cyperaceae individuals were analyzed under different tools such as light and transmission electron microscopy, which included cytochemistry and immunogold procedures. The results showed that maturing pollen in Cyperaceae presents some unusual endomembrane behaviors. Endoplasmic reticulum and dictyosomes are concerned in classic secretion pathways in vegetative cells, and possibly the late breakdown of degenerative microspores. However, cortical and concentric endoplasmic reticulum are also present and are possibly related to other functions aside the biosynthetic pathway. Unconventional secretion of large membrane-bound bodies containing cell wall precursors was also observed and confirmed by immunogold. However, since these bodies most likely receive material from dictyosomes, as observed in silver nitrate reaction, the "unconventional" status of this secretion is debatable. Reports of the literature show that these unusual endomembrane formations are not exclusive of the sedge pollen, but little attention have been given to them so far. This could represent an opportunity to re-examine our understanding on the endomembrane system in pollen cells in general.
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Affiliation(s)
- Danilo M Rocha
- Laboratory of Plant Anatomy LAVeg, Department of Botany, Institute of Biosciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - André L L Vanzela
- Laboratory of Cytogenetics and Plant Diversity, Department of General Biology, Center of Biological Sciences, Universidade Estadual de Londrina, Londrina, Brazil
| | - Jorge E A Mariath
- Laboratory of Plant Anatomy LAVeg, Department of Botany, Institute of Biosciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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18
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Ohashi Y, Mori T, Igawa T. Behavior of filamentous temperature-sensitive Z2 (FtsZ2) in the male gametophyte during sexual reproduction processes of flowering plants. PROTOPLASMA 2020; 257:1201-1210. [PMID: 32300955 DOI: 10.1007/s00709-020-01503-2] [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: 01/20/2020] [Accepted: 03/20/2020] [Indexed: 06/11/2023]
Abstract
Filamentous temperature-sensitive Z (FtsZ) is a critical division protein in bacteria that functions in forming a Z-ring structure to constrict the cell. Since the establishment of the plastid by endosymbiosis of a cyanobacterium into a eukaryotic cell, division via Z-ring formation has been conserved in the plastids of flowering plants. The FtsZ gene was transferred from the cyanobacterial ancestor of plastids to the eukaryotic nuclear genome during evolution, and flowering plants evolved two FtsZ homologs, FtsZ1 and FtsZ2, which are involved in chloroplast division through distinct molecular functions. Regarding the behaviors of FtsZ in nonphotosynthetic cells, the plastid localization of FtsZ1 proteins in the cytoplasm of microspores and pollen vegetative cells but not in generative cells or sperm cells has been reported. On the other hand, the significant accumulation of FtsZ2 transcripts in generative cells has been reported. However, the synthesis of FtsZ2 in the male gamete has not been investigated. Additionally, FtsZ2 behavior has not been analyzed in pollen, a nonphotosynthetic male tissue. Here, we report FtsZ2 protein behaviors in the male gamete by analyzing the localization patterns of GFP-fused protein at various pollen developmental stages and in gametes during the fertilization process. Our results showed that FtsZ2 localization coincided with that of plastids. FtsZ2 protein in male gametes was almost absent, despite the presence of the transcripts. Moreover, transmission of paternal FtsZ2 transcripts to the zygote and endosperm was not observed.
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Affiliation(s)
- Yukino Ohashi
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo-shi, Chiba, 271-8510, Japan
| | - Toshiyuki Mori
- Department of Tropical Medicine and Parasitology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Tomoko Igawa
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo-shi, Chiba, 271-8510, Japan.
- Plant Molecular Science Center, Chiba University, 648 Matsudo, Matsudo-shi, Chiba, 271-8510, Japan.
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19
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Cao Y, Cai W, Chen X, Chen M, Chu J, Liang W, Persson S, Liu Z, Zhang D. Bright Fluorescent Vacuolar Marker Lines Allow Vacuolar Tracing Across Multiple Tissues and Stress Conditions in Rice. Int J Mol Sci 2020; 21:E4203. [PMID: 32545623 PMCID: PMC7352260 DOI: 10.3390/ijms21124203] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/27/2020] [Accepted: 06/10/2020] [Indexed: 11/17/2022] Open
Abstract
The vacuole is indispensable for cells to maintain their water potential and to respond to environmental changes. Nevertheless, investigations of vacuole morphology and its functions have been limited to Arabidopsis thaliana with few studies in the model crop rice (Oryza sativa). Here, we report the establishment of bright rice vacuole fluorescent reporter systems using OsTIP1;1, a tonoplast water channel protein, fused to either an enhanced green fluorescent protein or an mCherry red fluorescent protein. We used the corresponding transgenic rice lines to trace the vacuole morphology in roots, leaves, anthers, and pollen grains. Notably, we observed dynamic changes in vacuole morphologies in pollen and root epidermis that corresponded to their developmental states as well as vacuole shape alterations in response to abiotic stresses. Our results indicate that the application of our vacuole markers may aid in understanding rice vacuole function and structure across different tissues and environmental conditions in rice.
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Affiliation(s)
- Yiran Cao
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
| | - Wenguo Cai
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
- Flow Station of Post-doctoral Scientific Research, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaofei Chen
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
| | - Mingjiao Chen
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
| | - Jianjun Chu
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
| | - Wanqi Liang
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
| | - Staffan Persson
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
- School of Biosciences, University of Melbourne, Parkville Victoria 3010, Melbourne, Australia
| | - Zengyu Liu
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
| | - Dabing Zhang
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.C.); (W.C.); (X.C.); (M.C.); (J.C.); (W.L.); (S.P.)
- School of Agriculture, Food, and Wine, University of Adelaide, Waite Campus, Urrbrae, South Australia 5064, Australia
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20
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Yamada K, Basak AK, Goto-Yamada S, Tarnawska-Glatt K, Hara-Nishimura I. Vacuolar processing enzymes in the plant life cycle. THE NEW PHYTOLOGIST 2020; 226:21-31. [PMID: 31679161 DOI: 10.1111/nph.16306] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 10/14/2019] [Indexed: 05/23/2023]
Abstract
Vacuolar processing enzyme (VPE) is a cysteine-type endopeptidase that has a substrate-specificity for asparagine or aspartic acid residues and cleaves peptide bonds at their carboxyl-terminal side. Various vacuolar proteins are synthesized as larger proprotein precursors, and VPE is an important initiator of maturation and activation of these proteins. It mediates programmed cell death (PCD) by provoking vacuolar rupture and initiating the proteolytic cascade leading to PCD. Vacuolar processing enzyme also possesses a peptide ligation activity, which is responsible for producing cyclic peptides in several plant species. These unique functions of VPE support developmental and environmental responses in plants. The number of VPE homologues is higher in angiosperm species, indicating that there has been differentiation and specialization of VPE function over the course of evolution. Angiosperm VPEs are separated into two major types: the γ-type VPEs, which are expressed mainly in vegetative organs, and the β-type VPEs, whose expression occurs mainly in storage organs; in eudicots, the δ-type VPEs are further separated within γ-type VPEs. This review also considers the importance of processing and peptide ligation by VPE in vacuolar protein maturation.
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Affiliation(s)
- Kenji Yamada
- Małopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
| | - Arpan Kumar Basak
- Małopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Krakow, 30-387, Poland
| | - Shino Goto-Yamada
- Małopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
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Oh SA, Hoai TNT, Park HJ, Zhao M, Twell D, Honys D, Park SK. MYB81, a microspore-specific GAMYB transcription factor, promotes pollen mitosis I and cell lineage formation in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:590-603. [PMID: 31610057 DOI: 10.1111/tpj.14564] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/10/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
Sexual reproduction in flowering plants relies on the production of haploid gametophytes that consist of germline and supporting cells. During male gametophyte development, the asymmetric mitotic division of an undetermined unicellular microspore segregates these two cell lineages. To explore genetic regulation underlying this process, we screened for pollen cell patterning mutants and isolated the heterozygous myb81-1 mutant that sheds ~50% abnormal pollen. Typically, myb81-1 microspores fail to undergo pollen mitosis I (PMI) and arrest at polarized stage with a single central vacuole. Although most myb81-1 microspores degenerate without division, a small fraction divides at later stages and fails to acquire correct cell fates. The myb81-1 allele is transmitted normally through the female, but rarely through pollen. We show that myb81-1 phenotypes result from impaired function of the GAMYB transcription factor MYB81. The MYB81 promoter shows microspore-specific activity and a MYB81-RFP fusion protein is only expressed in a narrow window prior to PMI. Ectopic expression of MYB81 driven by various promoters can severely impair vegetative or reproductive development, reflecting the strict microspore-specific control of MYB81. Our data demonstrate that MYB81 has a key role in the developmental progression of microspores, enabling formation of the two male cell lineages that are essential for sexual reproduction in Arabidopsis.
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Affiliation(s)
- Sung-Aeong Oh
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Thuong Nguyen Thi Hoai
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Hyo-Jin Park
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Mingmin Zhao
- Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester, LE1 7RH, UK
| | - David Twell
- Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester, LE1 7RH, UK
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic
| | - Soon-Ki Park
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
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22
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Zheng RH, Su SD, Xiao H, Tian HQ. Calcium: A Critical Factor in Pollen Germination and Tube Elongation. Int J Mol Sci 2019; 20:E420. [PMID: 30669423 PMCID: PMC6358865 DOI: 10.3390/ijms20020420] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/20/2018] [Accepted: 12/25/2018] [Indexed: 02/07/2023] Open
Abstract
Pollen is the male gametophyte of higher plants. Its major function is to deliver sperm cells to the ovule to ensure successful fertilization. During this process, many interactions occur among pollen tubes and pistil cells and tissues, and calcium ion (Ca2+) dynamics mediate these interactions among cells to ensure that pollen reaches the embryo sac. Although the precise functions of Ca2+ dynamics in the cells are unknown, we can speculate about its roles on the basis of its spatial and temporal characteristics during these interactions. The results of many studies indicate that calcium is a critical element that is strongly related to pollen germination and pollen tube growth.
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Affiliation(s)
- Ren Hua Zheng
- The Key Laboratory of Timber Forest Breeding and Cultivation for Mountainous Areas in Southern China, Fujian Academy of Forestry, Fuzhou 350012, China.
| | - Shun De Su
- The Key Laboratory of Timber Forest Breeding and Cultivation for Mountainous Areas in Southern China, Fujian Academy of Forestry, Fuzhou 350012, China.
| | - Hui Xiao
- The Key Laboratory of Timber Forest Breeding and Cultivation for Mountainous Areas in Southern China, Fujian Academy of Forestry, Fuzhou 350012, China.
| | - Hui Qiao Tian
- School of Life Sciences, Xiamen University, Xiamen 361102, China.
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23
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Liang X, Feng QN, Li S, Zhang Y. Vacuolar trafficking in pollen tube growth and guidance. PLANT SIGNALING & BEHAVIOR 2018; 13:e1464854. [PMID: 29701540 PMCID: PMC6103282 DOI: 10.1080/15592324.2018.1464854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
Vacuoles are versatile organelles in plant cells, critical for growth and responses to environmental cues. Vacuoles are dynamic tubular structures in pollen tubes, the male gametophytes. Mutations at vacuolar fusion machinery caused male gametophytic lethality by affecting pollen tube growth and guidance, which are critical steps leading to angiosperm reproduction. In comparison, the role of vacuolar trafficking and its cargoes in this process is less understood. In this mini-review, we summarize old and recent findings that indicate the involvement of vacuolar trafficking in pollen tube growth and guidance. We also point at future studies that would provide insights into a key role of vacuolar trafficking and its cargos in pollen tube growth and guidance.
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Affiliation(s)
- Xin Liang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Qiang-Nan Feng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Sha Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, 271018, China
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24
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Abstract
In this introductory chapter, we describe male germline development in plants taking Arabidopsis thaliana as a reference species. We first describe the transition from sporophytic to germline development, then microsporogenesis including meiosis, followed by male gametophyte development prior to pollination, and finally the progamic phase culminating in double fertilization, which leads to the formation of the embryo and the endosperm. For detailed information on some of these processes or on the molecular underpinning of certain fate transitions, we refer the reader to recent reviews. An important but often neglected aspect of male gametophyte development is the formation of the unique pollen cell wall. In contrast to that of other plant cells, the pollen cell wall is composed of two principal layers, the intine and exine. While the intine, the inner pecto-cellulosic cell wall layer, is biochemically and structurally similar to a "classical" plant cell wall, the exine is a unique composite with sporopollenin as its main component. Biosynthesis of the cell wall is remarkably similar between the spores of mosses and ferns, and pollen of seed plants, although slight differences exist, even between closely related species (reviewed in Wallace et al., AoB Plants 2011:plr027, 2011). In the latter sections of this chapter, we will present a brief overview of cell wall development in Arabidopsis pollen, where this aspect has been intensively studied.
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25
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Huang X, Peng X, Xie F, Mao W, Chen H, Sun MX. The stereotyped positioning of the generative cell associated with vacuole dynamics is not required for male gametogenesis in rice pollen. THE NEW PHYTOLOGIST 2018; 218:463-469. [PMID: 29424430 DOI: 10.1111/nph.15038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/14/2018] [Indexed: 06/08/2023]
Abstract
During male gametogenesis in cereals, the generative cell undergoes a positioning process that parallels the dynamics of the central vacuole, which is believed to be associated with generative cell movement in the male gametophyte. However, the impact of the generative cell positioning and the central vacuole dynamics on male gametogenesis has remained poorly understood. Here, we report that OsGCD1 (GAMETE CELLS DEFECTIVE1) dysfunction influenced pollen development and disrupted pollen germination. Loss of function of OsGCD1 altered the central vacuole dynamics and the generative cell was mispositioned. Nevertheless, twin sperm cells were generated normally, indicating that gametogenesis does not rely on positional information as long as a generative cell is produced. The normal vacuole dynamics seems necessary only for pollen maturation and germination. Our findings also indicate that osgcd1 mutation resulted in rice male sterility in which pollen has full cell viability and generated normal gametes, but lacks the potential to germinate.
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Affiliation(s)
- Xiaorong Huang
- College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Xiongbo Peng
- College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Fei Xie
- College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Wanying Mao
- College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Hong Chen
- College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Meng-Xiang Sun
- College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
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26
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Rotsch AH, Kopka J, Feussner I, Ischebeck T. Central metabolite and sterol profiling divides tobacco male gametophyte development and pollen tube growth into eight metabolic phases. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:129-146. [PMID: 28685881 DOI: 10.1111/tpj.13633] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 06/23/2017] [Accepted: 06/26/2017] [Indexed: 05/23/2023]
Abstract
While changes in the transcriptome and proteome of developing pollen have been investigated in tobacco and other species, the metabolic consequences remain rather unclear. Here, a broad range of metabolites was investigated in close succession of developmental stages. Thirteen stages of tobacco male gametophyte development were collected, ranging from tetrads to pollen tubes. Subsequently, the central metabolome and sterol composition were analyzed by GC-mass spectrometry (MS), monitoring 77 metabolites and 29 non-identified analytes. The overall results showed that development and tube growth could be divided into eight metabolic phases with the phase including mitosis I being most distinct. During maturation, compounds such as sucrose and proline accumulated. These were degraded after rehydration, while γ-aminobutyrate transiently increased, possibly deriving from proline breakdown. Sterol analysis revealed that tetrads harbor similar sterols as leaves, but throughout maturation unusual sterols increased. Lastly, two further sterols exclusively accumulated in pollen tubes. This study allows a deeper look into metabolic changes during the development of a quasi-single cell type. Metabolites accumulating during maturation might accelerate pollen germination and tube growth, protect from desiccation, and feed pollinators. Future studies of the underlying processes orchestrating the changes in metabolite levels might give valuable insights into cellular regulation of plant metabolism.
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Affiliation(s)
- Alexander H Rotsch
- Department of Plant Biochemistry, University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
| | - Joachim Kopka
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
- Department of Plant Biochemistry, University of Goettingen, Goettingen Center for Molecular Biosciences (GZMB), Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
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27
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Feng C, Wang JG, Liu HH, Li S, Zhang Y. Arabidopsis adaptor protein 1G is critical for pollen development. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:594-599. [PMID: 28544342 DOI: 10.1111/jipb.12556] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/22/2017] [Indexed: 06/07/2023]
Abstract
Pollen development is a pre-requisite for sexual reproduction of angiosperms, during which various cellular activities are involved. Pollen development accompanies dynamic remodeling of vacuoles through fission and fusion, disruption of which often compromises pollen viability. We previously reported that the Y subunit of adaptor protein 1 (AP1G) mediates synergid degeneration during pollen tube reception. Here, we demonstrate that AP1G is essential for pollen development. AP1G loss-of-function resulted in male gametophytic lethality due to defective pollen development. By ultrastructural analysis and fluorescence labeling, we demonstrate that AP1G loss-of-function compromised dynamic vacuolar remodeling during pollen development and impaired vacuolar acidification of pollen. Results presented here support a key role of vacuoles in gametophytic pollen development.
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Affiliation(s)
- Chong Feng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Jia-Gang Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Hai-Hong Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Sha Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
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28
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Li DX, Hu HY, Li G, Ru ZG, Tian HQ. Calcium controls the formation of vacuoles from mitochondria to regulate microspore development in wheat. PLANT REPRODUCTION 2017; 30:131-139. [PMID: 28900728 DOI: 10.1007/s00497-017-0309-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 09/06/2017] [Indexed: 06/07/2023]
Abstract
Potassium antimonite was used to investigate the localisation of calcium in developing wheat anthers to examine the relationship between Ca2+ and pollen development. During anther development, calcium precipitate formation increased in anther wall cells prior to microspore mother cell meiosis and appeared in microspores, suggesting the presence of a calcium influx from anther wall cells into the locule. Initially, the precipitates in microspore cytoplasm primarily accumulated in the mitochondria and destroyed their inner membranes (cisterns) to become small vacuoles, which expanded and fused, ultimately becoming a large vacuole during microspore vacuolisation. After microspore division and large vacuole decomposition, many calcium precipitates again accumulated in the small vacuoles, indicating that calcium from the large vacuole moved back into the cytoplasm of bicellular pollen.
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Affiliation(s)
- Dong Xiao Li
- Henan Institute of Science and Technology, Xinxiang, 453003, Henan, China
| | - Hai Yan Hu
- Henan Institute of Science and Technology, Xinxiang, 453003, Henan, China
- Collaborative Innovation Center of Modern Biological Breeding, Xinxiang, 453003, Henan, China
| | - Gan Li
- Henan Institute of Science and Technology, Xinxiang, 453003, Henan, China
- Collaborative Innovation Center of Modern Biological Breeding, Xinxiang, 453003, Henan, China
| | - Zhen Gang Ru
- Henan Institute of Science and Technology, Xinxiang, 453003, Henan, China
- Collaborative Innovation Center of Modern Biological Breeding, Xinxiang, 453003, Henan, China
| | - Hui Qiao Tian
- School of Life Sciences, Xiamen University, Xiamen, 361005, Fujian, China.
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29
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Pérez Koldenkova V, Hatsugai N. Vacuolar convolution: possible mechanisms and role of phosphatidylinositol 3,5-bisphosphate. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:751-760. [PMID: 32480604 DOI: 10.1071/fp16443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 05/19/2017] [Indexed: 06/11/2023]
Abstract
The central or lytic vacuole is the largest intracellular organelle in plant cells, but we know unacceptably little about the mechanisms regulating its function in vivo. The underlying reasons are related to difficulties in accessing this organelle without disrupting the cellular integrity and to the dynamic morphology of the vacuole, which lacks a defined structure. Among such morphological changes, vacuolar convolution is probably the most commonly observed event, reflected in the (reversible) transformation of a large central vacuole into a structure consisting of interconnected bubbles of a smaller size. Such behaviour is observed in plant cells subjected to hyperosmotic stress but also takes place in physiological conditions (e.g. during stomatal closure). Although vacuolar convolution is a relatively common phenomenon in plants, studies aimed at elucidating its execution mechanisms are rather scarce. In the present review, we analyse the available evidence on the participation of the cellular cytoskeleton and ion transporters in vacuolar morphology dynamics, putting special emphasis on the available evidence of the role played by phosphatidylinositol 3,5-bisphosphate in this process.
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Affiliation(s)
- Vadim Pérez Koldenkova
- Laboratorio Nacional de Microscopía Avanzada, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Av. Cuauhtémoc, 330, Col. Doctores, Del. Cuauhtémoc. 06720, México D.F., Mexico
| | - Noriyuki Hatsugai
- Department of Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota St Paul, MN 55108, USA
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30
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Ugalde JM, Rodriguez-Furlán C, Rycke RD, Norambuena L, Friml J, León G, Tejos R. Phosphatidylinositol 4-phosphate 5-kinases 1 and 2 are involved in the regulation of vacuole morphology during Arabidopsis thaliana pollen development. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 250:10-19. [PMID: 27457979 DOI: 10.1016/j.plantsci.2016.05.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/16/2016] [Accepted: 05/18/2016] [Indexed: 06/06/2023]
Abstract
The pollen grains arise after meiosis of pollen mother cells within the anthers. A series of complex structural changes follows, generating mature pollen grains capable of performing the double fertilization of the female megasporophyte. Several signaling molecules, including hormones and lipids, have been involved in the regulation and appropriate control of pollen development. Phosphatidylinositol 4-phophate 5-kinases (PIP5K), which catalyze the biosynthesis of the phosphoinositide PtdIns(4,5)P2, are important for tip polar growth of root hairs and pollen tubes, embryo development, vegetative plant growth, and responses to the environment. Here, we report a role of PIP5Ks during microgametogenesis. PIP5K1 and PIP5K2 are expressed during early stages of pollen development and their transcriptional activity respond to auxin in pollen grains. Early male gametophytic lethality to certain grade was observed in both pip5k1(-/-) and pip5k2(-/-) single mutants. The number of pip5k mutant alleles is directly related to the frequency of aborted pollen grains suggesting the two genes are involved in the same function. Indeed PIP5K1 and PIP5K2 are functionally redundant since homozygous double mutants did not render viable pollen grains. The loss of function of PIP5K1 and PIP5K2results in defects in vacuole morphology in pollen at the later stages and epidermal root cells. Our results show that PIP5K1, PIP5K2 and phosphoinositide signaling are important cues for early developmental stages and vacuole formation during microgametogenesis.
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Affiliation(s)
- José-Manuel Ugalde
- Laboratorio de Reproducción y Desarrollo de Plantas, Centro de Biotecnología Vegetal, Universidad Andrés Bello, 8370146 Santiago, Chile
| | - Cecilia Rodriguez-Furlán
- Centro de Biologia Molecular Vegetal, Departamento de Biologia, Facultad de Ciencias, Universidad de Chile, 7800003 Santiago, Chile
| | - Riet De Rycke
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria
| | - Lorena Norambuena
- Centro de Biologia Molecular Vegetal, Departamento de Biologia, Facultad de Ciencias, Universidad de Chile, 7800003 Santiago, Chile
| | - Jiří Friml
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria; Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Gabriel León
- Laboratorio de Reproducción y Desarrollo de Plantas, Centro de Biotecnología Vegetal, Universidad Andrés Bello, 8370146 Santiago, Chile
| | - Ricardo Tejos
- Centro de Biologia Molecular Vegetal, Departamento de Biologia, Facultad de Ciencias, Universidad de Chile, 7800003 Santiago, Chile; Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium; Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Santiago, Chile.
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31
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Chaturvedi P, Ghatak A, Weckwerth W. Pollen proteomics: from stress physiology to developmental priming. PLANT REPRODUCTION 2016; 29:119-32. [PMID: 27271282 PMCID: PMC4909805 DOI: 10.1007/s00497-016-0283-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 05/05/2016] [Indexed: 05/19/2023]
Abstract
Pollen development and stress. In angiosperms, pollen or pollen grain (male gametophyte) is a highly reduced two- or three-cell structure which plays a decisive role in plant reproduction. Male gametophyte development takes place in anther locules where diploid sporophytic cells undergo meiotic division followed by two consecutive mitotic processes. A desiccated and metabolically quiescent form of mature pollen is released from the anther which lands on the stigma. Pollen tube growth takes place followed by double fertilization. Apart from its importance in sexual reproduction, pollen is also an interesting model system which integrates fundamental cellular processes like cell division, differentiation, fate determination, polar establishment, cell to cell recognition and communication. Recently, pollen functionality has been studied by multidisciplinary approaches which also include OMICS analyses like transcriptomics, proteomics and metabolomics. Here, we review recent advances in proteomics of pollen development and propose the process of developmental priming playing a key role to guard highly sensitive developmental processes.
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Affiliation(s)
- Palak Chaturvedi
- Department of Ecogenomics and Systems Biology, Faculty of Sciences, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Arindam Ghatak
- Department of Ecogenomics and Systems Biology, Faculty of Sciences, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
- School of Biotechnology and Bioinformatics, D.Y. Patil University, Sector No-15, CBD, Belapur, Navi Mumbai, India
| | - Wolfram Weckwerth
- Department of Ecogenomics and Systems Biology, Faculty of Sciences, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
- Vienna Metabolomics Center (VIME), University of Vienna, Vienna, Austria.
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32
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Heilmann I, Ischebeck T. Male functions and malfunctions: the impact of phosphoinositides on pollen development and pollen tube growth. PLANT REPRODUCTION 2016; 29:3-20. [PMID: 26676144 DOI: 10.1007/s00497-015-0270-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 11/17/2015] [Indexed: 05/12/2023]
Abstract
Phosphoinositides in pollen. In angiosperms, sexual reproduction is a series of complex biological events that facilitate the distribution of male generative cells for double fertilization. Angiosperms have no motile gametes, and the distribution units of generative cells are pollen grains, passively mobile desiccated structures, capable of delivering genetic material to compatible flowers over long distances and in an adverse environment. The development of pollen (male gametogenesis) and the formation of a pollen tube after a pollen grain has reached a compatible flower (pollen tube growth) are important aspects of plant developmental biology. In recent years, a wealth of information has been gathered about the molecular control of cell polarity, membrane trafficking and cytoskeletal dynamics underlying these developmental processes. In particular, it has been found that regulatory membrane phospholipids, such as phosphoinositides (PIs), are critical regulatory players, controlling key steps of trafficking and polarization. Characteristic features of PIs are the inositol phosphate headgroups of the lipids, which protrude from the cytosolic surfaces of membranes, enabling specific binding and recruitment of numerous protein partners containing specific PI-binding domains. Such recruitment is globally an early event in polarization processes of eukaryotic cells and also of key importance to pollen development and tube growth. Additionally, PIs serve as precursors of other signaling factors with importance to male gametogenesis. This review highlights the recent advances about the roles of PIs in pollen development and pollen function.
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Affiliation(s)
- Ingo Heilmann
- Department of Cellular Biochemistry, Institute for Biochemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120, Halle (Saale), Germany.
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany.
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33
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Liu Z, Boachon B, Lugan R, Tavares R, Erhardt M, Mutterer J, Demais V, Pateyron S, Brunaud V, Ohnishi T, Pencik A, Achard P, Gong F, Hedden P, Werck-Reichhart D, Renault H. A Conserved Cytochrome P450 Evolved in Seed Plants Regulates Flower Maturation. MOLECULAR PLANT 2015; 8:1751-1765. [PMID: 26388305 DOI: 10.1016/j.molp.2015.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 08/31/2015] [Accepted: 09/05/2015] [Indexed: 06/05/2023]
Abstract
Global inspection of plant genomes identifies genes maintained in low copies across taxa and under strong purifying selection, which are likely to have essential functions. Based on this rationale, we investigated the function of the low-duplicated CYP715 cytochrome P450 gene family that appeared early in seed plants and evolved under strong negative selection. Arabidopsis CYP715A1 showed a restricted tissue-specific expression in the tapetum of flower buds and in the anther filaments upon anthesis. cyp715a1 insertion lines showed a strong defect in petal development, and transient alteration of pollen intine deposition. Comparative expression analysis revealed the downregulated expression of genes involved in pollen development, cell wall biogenesis, hormone homeostasis, and floral sesquiterpene biosynthesis, especially TPS21 and several key genes regulating floral development such as MYB21, MYB24, and MYC2. Accordingly, floral sesquiterpene emission was suppressed in the cyp715a1 mutants. Flower hormone profiling, in addition, indicated a modification of gibberellin homeostasis and a strong disturbance of the turnover of jasmonic acid derivatives. Petal growth was partially restored by the active gibberellin GA3 or the functional analog of jasmonoyl-isoleucine, coronatine. CYP715 appears to function as a key regulator of flower maturation, synchronizing petal expansion and volatile emission. It is thus expected to be an important determinant of flower-insect interaction.
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Affiliation(s)
- Zhenhua Liu
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France
| | - Benoît Boachon
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France
| | - Raphaël Lugan
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France
| | - Raquel Tavares
- Laboratoire de Biométrie et Biologie Évolutive, Université Lyon 1, CNRS, 69622 Villeurbanne, France
| | - Mathieu Erhardt
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France
| | - Jérôme Mutterer
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France
| | - Valérie Demais
- Plateforme d'Imagerie In Vitro, IFR 37 de Neurosciences, 67084 Strasbourg, France
| | - Stéphanie Pateyron
- Transcriptomic Platform, Unité de Recherche en Génomique Végétale (URGV), INRA, Université d'Evry Val d'Essonne, CNRS, 91057 Evry, France
| | - Véronique Brunaud
- Bioinformatics for Predictive Genomics, URGV, INRA, Université d'Evry Val d'Essonne, CNRS, 91057 Evry, France
| | - Toshiyuki Ohnishi
- Graduate School of Agriculture, Shizuoka University, Shizuoka, 422-8529 Japan
| | - Ales Pencik
- Laboratory of Growth Regulators & Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University & Institute of Experimental Botany AS CR, 771 47 Olomouc, Czech Republic
| | - Patrick Achard
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France
| | - Fan Gong
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Peter Hedden
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Danièle Werck-Reichhart
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France; University of Strasbourg Institute for Advanced Study (USIAS), 67084 Strasbourg, France; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany.
| | - Hugues Renault
- Institute of Plant Molecular Biology, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, 67084 Strasbourg, France; University of Strasbourg Institute for Advanced Study (USIAS), 67084 Strasbourg, France; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany
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Mayer ES, Ben-Michael T, Kimhi S, Forer I, Rabinowitch HD, Kamenetsky R. Effects of different temperature regimes on flower development, microsporogenesis and fertility in bolting garlic (Allium sativum). FUNCTIONAL PLANT BIOLOGY : FPB 2015; 42:514-526. [PMID: 32480697 DOI: 10.1071/fp14262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 01/20/2015] [Indexed: 06/11/2023]
Abstract
Garlic (Allium sativum L.) cultivars do not develop fertile flowers and seeds. Therefore, garlic production and improvement depend exclusively on vegetative propagation. Recent advances in garlic research have enabled fertility restoration and the discovery of fertile and male-sterile genotypes; however, the environmental regulation of the reproductive process is still not clear. Garlic seeds are successfully produced in the Mediterrenean region, where the photoperiod is relatively short, whereas spring and summer temperatures are high. We hypothesise that, in bolting garlic, various stages of florogenesis are differentially regulated by temperature and that high temperatures might obstruct pollen production. The effects of eight combinations of controlled growth temperatures on fertile and male-sterile garlic clones were studied. In both genotypes, a gradual temperature increase before and during anthesis favoured intact flower development. Surprisingly, continuous exposure to moderate temperatures during the entire growth period resulted in poor flowering, anther abortion and reduced pollen production. In the male-sterile genotype, no growth regime improved pollen production, which is controlled by genetic mechanisms. In the male-fertile genotype, gradual temperature increase supported pollen production but a sharp transition to high temperatures resulted in rapid flower senescence and pollen abortion, thus supporting our research hypothesis. In both fertile and male-sterile plants, the most vulnerable phase of microsporogenesis is the unicellular microspore stage. Tapetal malformation is the major cause for malnutrition of the microspores, with consequent production of nonviable pollen grains.
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Affiliation(s)
- Einat Shemesh Mayer
- The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Tomer Ben-Michael
- The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Sagie Kimhi
- The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Itzhak Forer
- Institute of Plant Science, Agricultural Research Organisation, The Volcani Center, Bet Dagan 50250, Israel
| | - Haim D Rabinowitch
- The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Rina Kamenetsky
- Institute of Plant Science, Agricultural Research Organisation, The Volcani Center, Bet Dagan 50250, Israel
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Flores-Tornero M, Anoman AD, Rosa-Téllez S, Ros R. Lack of phosphoserine phosphatase activity alters pollen and tapetum development in Arabidopsis thaliana. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 235:81-8. [PMID: 25900568 DOI: 10.1016/j.plantsci.2015.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/25/2015] [Accepted: 03/02/2015] [Indexed: 05/06/2023]
Abstract
Formation of mature pollen grain, an essential process for the reproduction of higher plants, is affected in lines that are deficient in the enzymes of the phosphorylated pathway of serine biosynthesis (PPSB). Mutants of phosphoserine phosphatase (PSP), the enzyme that catalyses the last step of PPSB, are embryo-lethal. When they are complemented with a construct carrying PSP1 cDNA under the control of the 35S promoter (psp1.1 35S:PSP1), which is poorly expressed in anther tissues, plants display a wild-type phenotype, but are male-sterile. The pollen from the psp1.1 35S:PSP1 lines are shrunken and unviable. Here we report the morphological alterations that appear in the psp1.1 35S:PSP1 lines during microspore development. We show that the pollen wall from these lines presents a normal exine layer, but a shrunken and collapsed shape. Lack of PSP activity also affects oil bodies formation in the tapetosomes of tapetal cells which, in turn, may influence microspore pollen coat formation. All these results highlight the important role of the PPSB in the normal development of microspores in Arabidopsis thaliana.
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Affiliation(s)
- M Flores-Tornero
- ERI de Biotecnologia i Biomedicina, Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València, 46100 Burjassot (Valencia), Spain.
| | - A D Anoman
- ERI de Biotecnologia i Biomedicina, Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València, 46100 Burjassot (Valencia), Spain.
| | - S Rosa-Téllez
- ERI de Biotecnologia i Biomedicina, Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València, 46100 Burjassot (Valencia), Spain.
| | - R Ros
- ERI de Biotecnologia i Biomedicina, Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València, 46100 Burjassot (Valencia), Spain.
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Liu L. Ultramicroscopic examination of mature massulae of Habenaria arinaria (Orchidaceae). Micron 2015; 74:1-7. [PMID: 25910428 DOI: 10.1016/j.micron.2015.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/02/2015] [Accepted: 04/02/2015] [Indexed: 12/01/2022]
Abstract
The mature massula of H. arinaria was examined by means of transmission electron microscopy, with the aim to understand the nature of cohesion between grains, the accumulation of pollen storage reserves, and the behavior of the nucleus of the vegetative cell in this composite type of pollen. The massula was a union of a large number of polygonal pollen grains that were tightly linked together. The exine within the massula were highly simplified, consisting of a single layer of nexine-2, lacking tectum, bacula, and nexine-1, while all the four layers comprised the exine on the massula surface. The two layers of nexine-2 of adjacent grains fused into a seamless whole. Undoubtedly the fusion of the nexine-2 was the mechanism by which the grains of the massula were linked together. No starch grains, lipid bodies, or storage proteins were present in the mature massula, and so the composite pollen of this species belonged to a novel type with regard to storage reserves. The vegetative nucleus was not lobed and revealed a huge amount of highly condensed chromatin, indicating a quiescent status. The condensed status of the vegetative nuclei in this composite type of pollen system is in striking contrast to the highly decondensed status reported in the free type of pollen grains.
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Affiliation(s)
- Lin Liu
- School of Pharmacy, Linyi University, Linyi 276000, China.
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37
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Kim JS, Park YS, Nam HG, Park JW. Imaging a specific mRNA in pollen with atomic force microscopy. RSC Adv 2015. [DOI: 10.1039/c5ra00199d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Distribution of ammonium transporter mRNA in a sectioned pollen is studied at the higher resolution, and localization of the mRNA in the nucleus of the sperm cells is observed.
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Affiliation(s)
- Jung Sook Kim
- Department of Chemistry
- Pohang University of Science and Technology
- Pohang 790–784
- Republic of Korea
| | - Yu Shin Park
- Center for Core Research Facilities
- DGIST
- Daegu 711–873
- Republic of Korea
| | - Hong Gil Nam
- Center for Plant Aging Research
- Institute for Basic Science (IBS)
- Daegu 711–873
- Republic of Korea
- Department of New Biology
| | - Joon Won Park
- Department of Chemistry
- Pohang University of Science and Technology
- Pohang 790–784
- Republic of Korea
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38
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Martin MV, Distéfano AM, Bellido A, Córdoba JP, Soto D, Pagnussat GC, Zabaleta E. Role of mitochondria during female gametophyte development and fertilization in A. thaliana. Mitochondrion 2014; 19 Pt B:350-6. [DOI: 10.1016/j.mito.2014.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/27/2014] [Accepted: 01/31/2014] [Indexed: 10/25/2022]
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Zhu J, Wu X, Yuan S, Qian D, Nan Q, An L, Xiang Y. Annexin5 plays a vital role in Arabidopsis pollen development via Ca2+-dependent membrane trafficking. PLoS One 2014; 9:e102407. [PMID: 25019283 PMCID: PMC4097066 DOI: 10.1371/journal.pone.0102407] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 06/18/2014] [Indexed: 12/22/2022] Open
Abstract
The regulation of pollen development and pollen tube growth is a complicated biological process that is crucial for sexual reproduction in flowering plants. Annexins are widely distributed from protists to higher eukaryotes and play multiple roles in numerous cellular events by acting as a putative "linker" between Ca2+ signaling, the actin cytoskeleton and the membrane, which are required for pollen development and pollen tube growth. Our recent report suggested that downregulation of the function of Arabidopsis annexin 5 (Ann5) in transgenic Ann5-RNAi lines caused severely sterile pollen grains. However, little is known about the underlying mechanisms of the function of Ann5 in pollen. This study demonstrated that Ann5 associates with phospholipid membrane and this association is stimulated by Ca2+ in vitro. Brefeldin A (BFA) interferes with endomembrane trafficking and inhibits pollen germination and pollen tube growth. Both pollen germination and pollen tube growth of Ann5-overexpressing plants showed increased resistance to BFA treatment, and this effect was regulated by calcium. Overexpression of Ann5 promoted Ca2+-dependent cytoplasmic streaming in pollen tubes in vivo in response to BFA. Lactrunculin (LatB) significantly prohibited pollen germination and tube growth by binding with high affinity to monomeric actin and preferentially targeting dynamic actin filament arrays and preventing actin polymerization. Overexpression of Ann5 did not affect pollen germination or pollen tube growth in response to LatB compared with wild-type, although Ann5 interacts with actin filaments in a manner similar to some animal annexins. In addition, the sterile pollen phenotype could be only partially rescued by Ann5 mutants at Ca2+-binding sites when compared to the complete recovery by wild-type Ann5. These data demonstrated that Ann5 is involved in pollen development, germination and pollen tube growth through the promotion of endomembrane trafficking modulated by calcium. Our results provide reliable molecular mechanisms that underlie the function of Ann5 in pollen.
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Affiliation(s)
- Jingen Zhu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Xiaorong Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Shunjie Yuan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Dong Qian
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Qiong Nan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Lizhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
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Autophagy-related direct membrane import from ER/cytoplasm into the vacuole or apoplast: a hidden gateway also for secondary metabolites and phytohormones? Int J Mol Sci 2014; 15:7462-74. [PMID: 24786101 PMCID: PMC4057683 DOI: 10.3390/ijms15057462] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 03/18/2014] [Accepted: 03/18/2014] [Indexed: 02/06/2023] Open
Abstract
Transportation of low molecular weight cargoes into the plant vacuole represents an essential plant cell function. Several lines of evidence indicate that autophagy-related direct endoplasmic reticulum (ER) to vacuole (and also, apoplast) transport plays here a more general role than expected. This route is regulated by autophagy proteins, including recently discovered involvement of the exocyst subcomplex. Traffic from ER into the vacuole bypassing Golgi apparatus (GA) acts not only in stress-related cytoplasm recycling or detoxification, but also in developmentally-regulated biopolymer and secondary metabolite import into the vacuole (or apoplast), exemplified by storage proteins and anthocyanins. We propose that this pathway is relevant also for some phytohormones’ (e.g., auxin, abscisic acid (ABA) and salicylic acid (SA)) degradation. We hypothesize that SA is not only an autophagy inducer, but also a cargo for autophagy-related ER to vacuole membrane container delivery and catabolism. ER membrane localized enzymes will potentially enhance the area of biosynthetic reactive surfaces, and also, abundant ER localized membrane importers (e.g., ABC transporters) will internalize specific molecular species into the autophagosome biogenesis domain of ER. Such active ER domains may create tubular invaginations of tonoplast into the vacuoles as import intermediates. Packaging of cargos into the ER-derived autophagosome-like containers might be an important mechanism of vacuole and exosome biogenesis and cytoplasm protection against toxic metabolites. A new perspective on metabolic transformations intimately linked to membrane trafficking in plants is emerging.
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Zhu J, Yuan S, Wei G, Qian D, Wu X, Jia H, Gui M, Liu W, An L, Xiang Y. Annexin5 is essential for pollen development in Arabidopsis. MOLECULAR PLANT 2014; 7:751-4. [PMID: 24362755 DOI: 10.1093/mp/sst171] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Affiliation(s)
- Jingen Zhu
- a MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
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42
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Wudick MM, Luu DT, Tournaire-Roux C, Sakamoto W, Maurel C. Vegetative and sperm cell-specific aquaporins of Arabidopsis highlight the vacuolar equipment of pollen and contribute to plant reproduction. PLANT PHYSIOLOGY 2014; 164:1697-706. [PMID: 24492334 PMCID: PMC3982734 DOI: 10.1104/pp.113.228700] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The water and nutrient status of pollen is crucial to plant reproduction. Pollen grains of Arabidopsis (Arabidopsis thaliana) contain a large vegetative cell and two smaller sperm cells. Pollen grains express AtTIP1;3 and AtTIP5;1, two members of the Tonoplast Intrinsic Protein subfamily of aquaporins. To address the spatial and temporal expression pattern of the two homologs, C-terminal fusions of AtTIP1;3 and AtTIP5;1 with green fluorescent protein and mCherry, respectively, were expressed in transgenic Arabidopsis under the control of their native promoter. Confocal laser scanning microscopy revealed that AtTIP1;3 and AtTIP5;1 are specific for the vacuoles of the vegetative and sperm cells, respectively. The tonoplast localization of AtTIP5;1 was established by reference to fluorescent protein markers for the mitochondria and vacuoles of sperm and vegetative cells and is at variance with the claim that AtTIP5;1 is localized in vegetative cell mitochondria. AtTIP1;3-green fluorescent protein and AtTIP5;1-mCherry showed concomitant expression, from first pollen mitosis up to pollen tube penetration in the ovule, thereby revealing the dynamics of vacuole morphology in maturating and germinating pollen. Transfer DNA insertion mutants for either AtTIP1;3 or AtTIP5;1 showed no apparent growth phenotype and had no significant defect in male transmission of the mutated alleles. By contrast, a double knockout displayed an abnormal rate of barren siliques, this phenotype being more pronounced under limited water or nutrient supply. The overall data indicate that vacuoles of vegetative and sperm cells functionally interact and contribute to male fertility in adverse environmental conditions.
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Tanaka Y, Nishimura K, Kawamukai M, Oshima A, Nakagawa T. Redundant function of two Arabidopsis COPII components, AtSec24B and AtSec24C, is essential for male and female gametogenesis. PLANTA 2013; 238:561-75. [PMID: 23779001 DOI: 10.1007/s00425-013-1913-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 06/05/2013] [Indexed: 05/08/2023]
Abstract
Anterograde vesicle transport from the endoplasmic reticulum to the Golgi apparatus is the start of protein transport through the secretory pathway, in which the transport is mediated by coat protein complex II (COPII)-coated vesicles. Therefore, most proteins synthesized on the endoplasmic reticulum are loaded as cargo into COPII vesicles. The COPII is composed of the small GTPase Sar1 and two types of protein complexes (Sec23/24 and Sec13/31). Of these five COPII components, Sec24 is thought to recognize cargo that is incorporated into COPII vesicles by directly interacting with the cargo. The Arabidopsis genome encodes three types of Sec24 homologs (AtSec24A, AtSec24B, and AtSec24C). The subcellular dynamics and function of AtSec24A have been characterized. The intracellular distributions and functions of other AtSec24 proteins are not known, and the functional differences among the three AtSec24s remain unclear. Here, we found that all three AtSec24s were expressed in similar parts of the plant body and showed the same subcellular localization pattern. AtSec24B knockout plant, but not AtSec24C knockdown plant, showed mild male sterility with reduction of pollen germination. Significant decrease of AtSec24B and AtSec24C expression affected male and female gametogenesis in Arabidopsis thaliana. Our results suggested that the redundant function of AtSec24B and AtSec24C is crucial for the development of plant reproductive cells. We propose that the COPII transport is involved in male and female gametogenesis in planta.
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Affiliation(s)
- Yuji Tanaka
- Department of Molecular and Functional Genomics, Center for Integrated Research in Science, Shimane University, Nishikawatsu 1060, Matsue, 690-8504, Japan
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44
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Ensuring Reproduction at High Temperatures: The Heat Stress Response during Anther and Pollen Development. PLANTS 2013; 2:489-506. [PMID: 27137389 PMCID: PMC4844380 DOI: 10.3390/plants2030489] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 06/28/2013] [Accepted: 07/03/2013] [Indexed: 01/01/2023]
Abstract
Sexual reproduction in flowering plants is very sensitive to environmental stresses, particularly to thermal insults which frequently occur when plants grow in field conditions in the warm season. Although abnormalities in both male and female reproductive organs due to high temperatures have been described in several crops, the failure to set fruits has mainly been attributed to the high sensitivity of developing anthers and pollen grains, particularly at certain developmental stages. A global view of the molecular mechanisms involved in the response to high temperatures in the male reproductive organs will be presented in this review. In addition, transcriptome and proteomic data, currently available, will be discussed in the light of physiological and metabolic changes occurring during anther and pollen development. A deep understanding of the molecular mechanisms involved in the stress response to high temperatures in flowers and, particularly, in the male reproductive organs will be a major step towards development of effective breeding strategies for high and stable production in crop plants.
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Chaturvedi P, Ischebeck T, Egelhofer V, Lichtscheidl I, Weckwerth W. Cell-specific analysis of the tomato pollen proteome from pollen mother cell to mature pollen provides evidence for developmental priming. J Proteome Res 2013; 12:4892-903. [PMID: 23731163 DOI: 10.1021/pr400197p] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Tomato is a globally important crop grown and consumed worldwide. Its reproductive activity is highly sensitive to environmental fluctuations, for instance temperature and drought. Here, pollen development is one of the most decisive processes. The present study aims for the identification of cell-specific proteins during pollen developmental stages of tomato. We have setup a protocol for stage-specific pollen isolation including microsporocytes (pollen mother cells), tetrads, microspores, polarized microspores, and mature pollen. Proteins were extracted using phenol and prefractionated using SDS-PAGE followed by protein digestion, peptide extraction, and desalting. Identification and quantification of proteins were performed using nanoHPLC coupled to LTQ-Orbitrap-MS. In total, 1821 proteins were identified. Most of these proteins were classified based on their homology and designated functions of orthologs. Cluster and principal components analysis revealed stage-specific proteins and demonstrated that pollen development of tomato is a highly controlled sequential process at the proteome level. Intermediate stages such as tetrad and polarized microspore are clearly distinguished by different functionality compared to other stages. From the predicted functions, energy-related proteins are increased during the later stages of development, which indicates that pollen germination depends upon presynthesized proteins in mature pollen. In contrast, heat stress-related proteins are highly abundant in very early developmental stages, suggesting a dominant role in stress protection. Taken together, the data provide a first cell-specific protein reference set for tomato pollen development from pollen mother cells to the mature pollen and give evidence for developmentally controlled processes that might help to prepare the cells for specific developmental programs and environmental stresses.
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Affiliation(s)
- Palak Chaturvedi
- Department of Molecular Systems Biology, Faculty of Sciences, University of Vienna , Althanstrasse 14, A-1090, Vienna, Austria
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46
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Missbach S, Weis BL, Martin R, Simm S, Bohnsack MT, Schleiff E. 40S ribosome biogenesis co-factors are essential for gametophyte and embryo development. PLoS One 2013; 8:e54084. [PMID: 23382868 PMCID: PMC3559688 DOI: 10.1371/journal.pone.0054084] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 12/05/2012] [Indexed: 12/13/2022] Open
Abstract
Ribosome biogenesis is well described in Saccharomyces cerevisiae. In contrast only very little information is available on this pathway in plants. This study presents the characterization of five putative protein co-factors of ribosome biogenesis in Arabidopsis thaliana, namely Rrp5, Pwp2, Nob1, Enp1 and Noc4. The characterization of the proteins in respect to localization, enzymatic activity and association with pre-ribosomal complexes is shown. Additionally, analyses of T-DNA insertion mutants aimed to reveal an involvement of the plant co-factors in ribosome biogenesis. The investigated proteins localize mainly to the nucleolus or the nucleus, and atEnp1 and atNob1 co-migrate with 40S pre-ribosomal complexes. The analysis of T-DNA insertion lines revealed that all proteins are essential in Arabidopsis thaliana and mutant plants show alterations of rRNA intermediate abundance already in the heterozygous state. The most significant alteration was observed in the NOB1 T-DNA insertion line where the P-A3 fragment, a 23S-like rRNA precursor, accumulated. The transmission of the T-DNA through the male and female gametophyte was strongly inhibited indicating a high importance of ribosome co-factor genes in the haploid stages of plant development. Additionally impaired embryogenesis was observed in some mutant plant lines. All results support an involvement of the analyzed proteins in ribosome biogenesis but differences in rRNA processing, gametophyte and embryo development suggested an alternative regulation in plants.
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Affiliation(s)
- Sandra Missbach
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Benjamin L. Weis
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Roman Martin
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Stefan Simm
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Markus T. Bohnsack
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
- Cluster of Excellence Frankfurt; Goethe University, Frankfurt/Main, Germany
| | - Enrico Schleiff
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
- Cluster of Excellence Frankfurt; Goethe University, Frankfurt/Main, Germany
- Center of Membrane Proteomics, Goethe University, Frankfurt/Main, Germany
- * E-mail:
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47
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Roschzttardtz H, Conéjéro G, Divol F, Alcon C, Verdeil JL, Curie C, Mari S. New insights into Fe localization in plant tissues. FRONTIERS IN PLANT SCIENCE 2013; 4:350. [PMID: 24046774 PMCID: PMC3764369 DOI: 10.3389/fpls.2013.00350] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 08/20/2013] [Indexed: 05/02/2023]
Abstract
Deciphering cellular iron (Fe) homeostasis requires having access to both quantitative and qualitative information on the subcellular pools of Fe in tissues and their dynamics within the cells. We have taken advantage of the Perls/DAB Fe staining procedure to perform a systematic analysis of Fe distribution in roots, leaves and reproductive organs of the model plant Arabidopsis thaliana, using wild-type and mutant genotypes affected in iron transport and storage. Roots of soil-grown plants accumulate iron in the apoplast of the central cylinder, a pattern that is strongly intensified when the citrate effluxer FRD3 is not functional, thus stressing the importance of citrate in the apoplastic movement of Fe. In leaves, Fe level is low and only detected in and around vascular tissues. In contrast, Fe staining in leaves of iron-treated plants extends in the surrounding mesophyll cells where Fe deposits, likely corresponding to Fe-ferritin complexes, accumulate in the chloroplasts. The loss of ferritins in the fer1,3,4 triple mutant provoked a massive accumulation of Fe in the apoplastic space, suggesting that in the absence of iron buffering in the chloroplast, cells activate iron efflux and/or repress iron influx to limit the amount of iron in the cell. In flowers, Perls/DAB staining has revealed a major sink for Fe in the anthers. In particular, developing pollen grains accumulate detectable amounts of Fe in small-size intracellular bodies that aggregate around the vegetative nucleus at the binuclear stage and that were identified as amyloplasts. In conclusion, using the Perls/DAB procedure combined to selected mutant genotypes, this study has established a reliable atlas of Fe distribution in the main Arabidopsis organs, proving and refining long-assumed intracellular locations and uncovering new ones. This "iron map" of Arabidopsis will serve as a basis for future studies of possible actors of iron movement in plant tissues and cell compartments.
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Affiliation(s)
| | | | | | | | | | | | - Stéphane Mari
- *Correspondence: Stéphane Mari, Institut National pour le Recherche Agronomique, Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, INRA/SupAgro, place Viala, bâtiment 7, Montpellier, F-34060, France e-mail:
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48
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Roschzttardtz H, Conéjéro G, Divol F, Alcon C, Verdeil JL, Curie C, Mari S. New insights into Fe localization in plant tissues. FRONTIERS IN PLANT SCIENCE 2013; 4:350. [PMID: 24046774 DOI: 10.3389/fpls201300350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 08/20/2013] [Indexed: 05/22/2023]
Abstract
Deciphering cellular iron (Fe) homeostasis requires having access to both quantitative and qualitative information on the subcellular pools of Fe in tissues and their dynamics within the cells. We have taken advantage of the Perls/DAB Fe staining procedure to perform a systematic analysis of Fe distribution in roots, leaves and reproductive organs of the model plant Arabidopsis thaliana, using wild-type and mutant genotypes affected in iron transport and storage. Roots of soil-grown plants accumulate iron in the apoplast of the central cylinder, a pattern that is strongly intensified when the citrate effluxer FRD3 is not functional, thus stressing the importance of citrate in the apoplastic movement of Fe. In leaves, Fe level is low and only detected in and around vascular tissues. In contrast, Fe staining in leaves of iron-treated plants extends in the surrounding mesophyll cells where Fe deposits, likely corresponding to Fe-ferritin complexes, accumulate in the chloroplasts. The loss of ferritins in the fer1,3,4 triple mutant provoked a massive accumulation of Fe in the apoplastic space, suggesting that in the absence of iron buffering in the chloroplast, cells activate iron efflux and/or repress iron influx to limit the amount of iron in the cell. In flowers, Perls/DAB staining has revealed a major sink for Fe in the anthers. In particular, developing pollen grains accumulate detectable amounts of Fe in small-size intracellular bodies that aggregate around the vegetative nucleus at the binuclear stage and that were identified as amyloplasts. In conclusion, using the Perls/DAB procedure combined to selected mutant genotypes, this study has established a reliable atlas of Fe distribution in the main Arabidopsis organs, proving and refining long-assumed intracellular locations and uncovering new ones. This "iron map" of Arabidopsis will serve as a basis for future studies of possible actors of iron movement in plant tissues and cell compartments.
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Affiliation(s)
- Hannetz Roschzttardtz
- Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National pour la Recherche Agronomique, Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, INRA/SupAgro,Université Montpellier 2 Montpellier, France
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49
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Dal Bosco C, Dovzhenko A, Liu X, Woerner N, Rensch T, Eismann M, Eimer S, Hegermann J, Paponov IA, Ruperti B, Heberle-Bors E, Touraev A, Cohen JD, Palme K. The endoplasmic reticulum localized PIN8 is a pollen-specific auxin carrier involved in intracellular auxin homeostasis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 71:860-70. [PMID: 22540348 DOI: 10.1111/j.1365-313x.2012.05037.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The plant hormone auxin is a mobile signal which affects nuclear transcription by regulating the stability of auxin/indole-3-acetic acid (IAA) repressor proteins. Auxin is transported polarly from cell to cell by auxin efflux proteins of the PIN family, but it is not as yet clear how auxin levels are regulated within cells and how access of auxin to the nucleus may be controlled. The Arabidopsis genome contains eight PINs, encoding proteins with a similar membrane topology. While five of the PINs are typically targeted polarly to the plasma membranes, the smallest members of the family, PIN5 and PIN8, seem to be located not at the plasma membrane but in endomembranes. Here we demonstrate by electron microscopy analysis that PIN8, which is specifically expressed in pollen, resides in the endoplasmic reticulum and that it remains internally localized during pollen tube growth. Transgenic Arabidopsis and tobacco plants were generated overexpressing or ectopically expressing functional PIN8, and its role in control of auxin homeostasis was studied. PIN8 ectopic expression resulted in strong auxin-related phenotypes. The severity of phenotypes depended on PIN8 protein levels, suggesting a rate-limiting activity for PIN8. The observed phenotypes correlated with elevated levels of free IAA and ester-conjugated IAA. Activation of the auxin-regulated synthetic DR5 promoter and of auxin response genes was strongly repressed in seedlings overexpressing PIN8 when exposed to 1-naphthalene acetic acid. Thus, our data show a functional role for endoplasmic reticulum-localized PIN8 and suggest a mechanism whereby PIN8 controls auxin thresholds and access of auxin to the nucleus, thereby regulating auxin-dependent transcriptional activity.
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Affiliation(s)
- Cristina Dal Bosco
- Institute of Biology II/Molecular Plant Physiology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany.
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50
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Lucca N, León G. Arabidopsis ACA7, encoding a putative auto-regulated Ca(2+)-ATPase, is required for normal pollen development. PLANT CELL REPORTS 2012; 31:651-9. [PMID: 22044965 DOI: 10.1007/s00299-011-1182-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 10/14/2011] [Accepted: 10/17/2011] [Indexed: 05/31/2023]
Abstract
Microgametogenesis is a complex process that involves numerous well-coordinated cell activities, ending with the production of pollen grains. Pollen development has been studied at the cytological level in Arabidopsis and other plant species, where its temporal time course has been defined. However, the molecular mechanism underlying this process is still unclear, since a relative small number of genes and/or processes have been identified as essential for pollen development. We have designed a methodology to select candidate genes for functional analysis, based on transcriptomic data obtained from different stages of pollen development. From our analyses, we selected At2g22950 as a candidate gene; this gene encodes a protein belonging to the auto-regulated Ca(2+)-ATPase family, ACA7. Microarray data indicate that ACA7 is expressed exclusively in developing pollen grains, with the highest level of mRNA at the time of the second pollen mitosis. Our RT-PCR experiments showed that ACA7 mRNA is detected exclusively in developing flowers. Confocal microscopy experiments showed a plasma membrane localization for the recombinant GFP:ACA7 protein. We identified two different insertional mutant lines, aca7-1 and aca7-2; plants from both mutant lines displayed a normal vegetative development but showed large amounts of dead pollen grains in mature flowers assayed by Alexander's staining. Histological analysis indicated that abnormalities are detected after the first pollen mitosis and we found a strong correlation between ACA7 mRNA accumulation and the severity of the phenotype. Our results indicate that ACA7 is a plasma membrane protein that has an important role during pollen development, possibly through regulation of Ca(2+) homeostasis.
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Affiliation(s)
- Noel Lucca
- Laboratorio de Reproducción y Desarrollo de Plantas, Centro de Biotecnología Vegetal, Universidad Andres Bello, República 217, Santiago, Chile
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