1
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Nielsen ME. Vesicle trafficking pathways in defence-related cell wall modifications: papillae and encasements. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:3700-3712. [PMID: 38606692 DOI: 10.1093/jxb/erae155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 04/11/2024] [Indexed: 04/13/2024]
Abstract
Filamentous pathogens that cause plant diseases such as powdery mildew, rust, anthracnose, and late blight continue to represent an enormous challenge for farmers worldwide. Interestingly, these pathogens, although phylogenetically distant, initiate pathogenesis in a very similar way by penetrating the cell wall and establishing a feeding structure inside the plant host cell. To prevent pathogen ingress, the host cell responds by forming defence structures known as papillae and encasements that are thought to mediate pre- and post-invasive immunity, respectively. This form of defence is evolutionarily conserved in land plants and is highly effective and durable against a broad selection of non-adapted filamentous pathogens. As most pathogens have evolved strategies to overcome the defences of only a limited range of host plants, the papilla/encasement response could hold the potential to become an optimal transfer of resistance from one plant species to another. In this review I lay out current knowledge of the involvement of membrane trafficking that forms these important defence structures and highlight some of the questions that still need to be resolved.
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Affiliation(s)
- Mads Eggert Nielsen
- University of Copenhagen, Faculty of Science, CPSC, Department of Plant and Environmental Sciences, 1871 Frederiksberg C, Denmark
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2
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Wiese C, Abele M, Al B, Altmann M, Steiner A, Kalbfuß N, Strohmayr A, Ravikumar R, Park CH, Brunschweiger B, Meng C, Facher E, Ehrhardt DW, Falter-Braun P, Wang ZY, Ludwig C, Assaad FF. Regulation of adaptive growth decisions via phosphorylation of the TRAPPII complex in Arabidopsis. J Cell Biol 2024; 223:e202311125. [PMID: 38558238 PMCID: PMC10983811 DOI: 10.1083/jcb.202311125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/31/2024] [Accepted: 02/15/2024] [Indexed: 04/04/2024] Open
Abstract
Plants often adapt to adverse or stress conditions via differential growth. The trans-Golgi network (TGN) has been implicated in stress responses, but it is not clear in what capacity it mediates adaptive growth decisions. In this study, we assess the role of the TGN in stress responses by exploring the previously identified interactome of the Transport Protein Particle II (TRAPPII) complex required for TGN structure and function. We identified physical and genetic interactions between AtTRAPPII and shaggy-like kinases (GSK3/AtSKs) and provided in vitro and in vivo evidence that the TRAPPII phosphostatus mediates adaptive responses to abiotic cues. AtSKs are multifunctional kinases that integrate a broad range of signals. Similarly, the AtTRAPPII interactome is vast and considerably enriched in signaling components. An AtSK-TRAPPII interaction would integrate all levels of cellular organization and instruct the TGN, a central and highly discriminate cellular hub, as to how to mobilize and allocate resources to optimize growth and survival under limiting or adverse conditions.
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Affiliation(s)
- Christian Wiese
- Biotechnology of Natural Products, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Miriam Abele
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Benjamin Al
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Melina Altmann
- Institute of Network Biology (INET), Molecular Targets and Therapeutics Center (MTTC), Helmholtz Center Munich, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Alexander Steiner
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Nils Kalbfuß
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Alexander Strohmayr
- Biotechnology of Natural Products, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Raksha Ravikumar
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Chan Ho Park
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Barbara Brunschweiger
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Chen Meng
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Eva Facher
- Systematic Botany and Mycology, Faculty of Biology, Ludwig-Maximilians-Universität (LMU) München, Planegg-Martinsried, Germany
| | - David W. Ehrhardt
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Pascal Falter-Braun
- Institute of Network Biology (INET), Molecular Targets and Therapeutics Center (MTTC), Helmholtz Center Munich, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Zhi-Yong Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Christina Ludwig
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Farhah F. Assaad
- Biotechnology of Natural Products, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
- Botany, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
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3
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Li X, Zhu P, Chen YJ, Huang L, Wang D, Newton DT, Hsu CC, Lin G, Tao WA, Staiger CJ, Zhang C. The EXO70 inhibitor Endosidin2 alters plasma membrane protein composition in Arabidopsis roots. FRONTIERS IN PLANT SCIENCE 2023; 14:1171957. [PMID: 37324680 PMCID: PMC10264680 DOI: 10.3389/fpls.2023.1171957] [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: 02/22/2023] [Accepted: 05/15/2023] [Indexed: 06/17/2023]
Abstract
To sustain normal growth and allow rapid responses to environmental cues, plants alter the plasma membrane protein composition under different conditions presumably by regulation of delivery, stability, and internalization. Exocytosis is a conserved cellular process that delivers proteins and lipids to the plasma membrane or extracellular space in eukaryotes. The octameric exocyst complex contributes to exocytosis by tethering secretory vesicles to the correct site for membrane fusion; however, whether the exocyst complex acts universally for all secretory vesicle cargo or just for specialized subsets used during polarized growth and trafficking is currently unknown. In addition to its role in exocytosis, the exocyst complex is also known to participate in membrane recycling and autophagy. Using a previously identified small molecule inhibitor of the plant exocyst complex subunit EXO70A1, Endosidin2 (ES2), combined with a plasma membrane enrichment method and quantitative proteomic analysis, we examined the composition of plasma membrane proteins in the root of Arabidopsis seedlings, after inhibition of the ES2-targetted exocyst complex, and verified our findings by live imaging of GFP-tagged plasma membrane proteins in root epidermal cells. The abundance of 145 plasma membrane proteins was significantly reduced following short-term ES2 treatments and these likely represent candidate cargo proteins of exocyst-mediated trafficking. Gene Ontology analysis showed that these proteins play diverse functions in cell growth, cell wall biosynthesis, hormone signaling, stress response, membrane transport, and nutrient uptake. Additionally, we quantified the effect of ES2 on the spatial distribution of EXO70A1 with live-cell imaging. Our results indicate that the plant exocyst complex mediates constitutive dynamic transport of subsets of plasma membrane proteins during normal root growth.
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Affiliation(s)
- Xiaohui Li
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Peipei Zhu
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Department of Chemistry, Purdue University, West Lafayette, IN, United States
| | - Yen-Ju Chen
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Lei Huang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Diwen Wang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - David T. Newton
- Department of Statistics, Purdue University, West Lafayette, IN, United States
| | - Chuan-Chih Hsu
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Guang Lin
- Department of Mathematics, Purdue University, West Lafayette, IN, United States
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, United States
| | - W. Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Department of Chemistry, Purdue University, West Lafayette, IN, United States
| | - Christopher J. Staiger
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States
| | - Chunhua Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
- Center for Plant Biology, Purdue University, West Lafayette, IN, United States
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4
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Shi Y, Luo C, Xiang Y, Qian D. Rab GTPases, tethers, and SNAREs work together to regulate Arabidopsis cell plate formation. FRONTIERS IN PLANT SCIENCE 2023; 14:1120841. [PMID: 36844074 PMCID: PMC9950755 DOI: 10.3389/fpls.2023.1120841] [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: 12/10/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Cell plates are transient structures formed by the fusion of vesicles at the center of the dividing plane; furthermore, these are precursors to new cell walls and are essential for cytokinesis. Cell plate formation requires a highly coordinated process of cytoskeletal rearrangement, vesicle accumulation and fusion, and membrane maturation. Tethering factors have been shown to interact with the Ras superfamily of small GTP binding proteins (Rab GTPases) and soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), which are essential for cell plate formation during cytokinesis and are fundamental for maintaining normal plant growth and development. In Arabidopsis thaliana, members of the Rab GTPases, tethers, and SNAREs are localized in cell plates, and mutations in the genes encoding these proteins result in typical cytokinesis-defective phenotypes, such as the formation of abnormal cell plates, multinucleated cells, and incomplete cell walls. This review highlights recent findings on vesicle trafficking during cell plate formation mediated by Rab GTPases, tethers, and SNAREs.
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5
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Gao Z, Liang Y, Wang Y, Xiao Y, Chen J, Yang X, Shi T. Genome-wide association study of traits in sacred lotus uncovers MITE-associated variants underlying stamen petaloid and petal number variations. FRONTIERS IN PLANT SCIENCE 2022; 13:973347. [PMID: 36212363 PMCID: PMC9539442 DOI: 10.3389/fpls.2022.973347] [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: 06/20/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
Understanding the genetic variants responsible for floral trait diversity is important for the molecular breeding of ornamental flowers. Widely used in water gardening for thousands of years, the sacred lotus exhibits a wide range of diversity in floral organs. Nevertheless, the genetic variations underlying various morphological characteristics in lotus remain largely unclear. Here, we performed a genome-wide association study of sacred lotus for 12 well-recorded ornamental traits. Given a moderate linkage disequilibrium level of 32.9 kb, we successfully identified 149 candidate genes responsible for seven flower traits and plant size variations, including many pleiotropic genes affecting multiple floral-organ-related traits, such as NnKUP2. Notably, we found a 2.75-kb presence-and-absence genomic fragment significantly associated with stamen petaloid and petal number variations, which was further confirmed by re-examining another independent population dataset with petal number records. Intriguingly, this fragment carries MITE transposons bound by siRNAs and is related to the expression differentiation of a nearby candidate gene between few-petalled and double-petalled lotuses. Overall, these genetic variations and candidate genes responsible for diverse lotus traits revealed by our GWAS highlight the role of transposon variations, particularly MITEs, in shaping floral trait diversity.
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Affiliation(s)
- Zhiyan Gao
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yuting Liang
- Wuhan Institute of Landscape Architecture, Wuhan, China
| | - Yuhan Wang
- Wuhan Institute of Design and Sciences, Wuhan, China
| | - Yingjie Xiao
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China
| | - Jinming Chen
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, China
| | - Xingyu Yang
- Wuhan Institute of Landscape Architecture, Wuhan, China
| | - Tao Shi
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, China
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6
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Žárský V. Exocyst functions in plants - secretion and autophagy. FEBS Lett 2022; 596:2324-2334. [PMID: 35729750 DOI: 10.1002/1873-3468.14430] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/03/2022] [Accepted: 06/03/2022] [Indexed: 11/09/2022]
Abstract
Tethering complexes mediate vesicle-target compartment contact. Octameric complex exocyst initiates vesicle exocytosis at specific cytoplasmic membrane domains. Plant exocyst is possibly stabilized at the membrane by a direct interaction between SEC3 and EXO70A. Land plants evolved three basic membrane-targeting EXO70 subfamilies, the evolution of which resulted in several types of exocyst with distinct functions within the same cell. Surprisingly, some of these EXO70-exocyst versions are implicated in autophagy as is animal exocyst or are involved in host defense, cell-wall fortification and secondary metabolites transport. Interestingly, EXO70Ds act as selective autophagy receptors in the regulation of cytokinin signalling pathway. Secretion of double membrane autophagy-related structures formed with the contribution of EXO70s to the apoplast hints at the possibility of secretory autophagy in plants.
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Affiliation(s)
- Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, Viničná 5, 128 44, Prague, Czech Republic.,Institute of Experimental Botany, v.v.i., Czech Academy of Sciences, Rozvojová 263, 165 02, Prague, Czech Republic
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7
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Sinclair R, Hsu G, Davis D, Chang M, Rosquete M, Iwasa JH, Drakakaki G. Plant cytokinesis and the construction of new cell wall. FEBS Lett 2022; 596:2243-2255. [PMID: 35695093 DOI: 10.1002/1873-3468.14426] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/10/2022]
Abstract
Cytokinesis in plants is fundamentally different from that in animals and fungi. In plant cells, a cell plate forms through the fusion of cytokinetic vesicles and then develops into the new cell wall, partitioning the cytoplasm of the dividing cell. The formation of the cell plate entails multiple stages that involve highly orchestrated vesicle accumulation, fusion, and membrane maturation, which occur concurrently with the timely deposition of polysaccharides such as callose, cellulose, and cross-linking glycans. This review summarizes the major stages in cytokinesis, endomembrane components involved in cell plate assembly and its transition to a new cell wall. An animation that can be widely used for educational purposes further summarizes the process.
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Affiliation(s)
- Rosalie Sinclair
- Department of Plant Sciences University of California Davis, Davis, CA, 95616, USA
| | - Grace Hsu
- Department of Biochemistry University of Utah, School of Medicine, Salt Lake City, UT, 84112, USA
| | - Destiny Davis
- Department of Plant Sciences University of California Davis, Davis, CA, 95616, USA.,Current address: Lawrence Berkeley National Lab, Emeryville, CA, 94608, USA
| | - Mingqin Chang
- Department of Plant Sciences University of California Davis, Davis, CA, 95616, USA
| | - Michel Rosquete
- Department of Plant Sciences University of California Davis, Davis, CA, 95616, USA.,Current address: Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Janet H Iwasa
- Department of Biochemistry University of Utah, School of Medicine, Salt Lake City, UT, 84112, USA
| | - Georgia Drakakaki
- Department of Plant Sciences University of California Davis, Davis, CA, 95616, USA
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8
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Hématy K, De Bellis D, Wang X, Mähönen AP, Geldner N. Analysis of exocyst function in endodermis reveals its widespread contribution and specificity of action. PLANT PHYSIOLOGY 2022; 189:557-566. [PMID: 35099565 PMCID: PMC9157074 DOI: 10.1093/plphys/kiac019] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
The exocyst is the main plasma membrane vesicle-tethering complex in eukaryotes and is composed of eight different subunits. Yet, in plant genomes, many subunits display multiple copies, thought to reflect evolution of complex subtypes with divergent functions. In Arabidopsis thaliana root endodermal cells, the isoform EXO70A1 is required for positioning of CASP1 at the Casparian Strip Domain, but not for its non-targeted secretion to the plasma membrane. Here, we show that exo84b resembles exo70a1 mutants regarding CASP1 mistargeting and secretion of apoplastic proteins, but exo84b additionally affects secretion of other integral plasma membrane proteins. Moreover, conditional, cell-type-specific gene editing of the single-copy core component SEC6 allows visualization of secretion defects in plant cells with a complete lack of exocyst complex function. Our approach opens avenues for deciphering the complexity/diversity of exocyst functions in plant cells and enables analysis of central trafficking components with lethal phenotypes.
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Affiliation(s)
- Kian Hématy
- Department of Plant Molecular Biology, University of Lausanne, Lausanne 1015, Switzerland
- Institut Jean-Pierre Bourgin, INRAe, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Damien De Bellis
- Department of Plant Molecular Biology, University of Lausanne, Lausanne 1015, Switzerland
- Electron Microscopy Facility, University of Lausanne, Lausanne 1015, Switzerland
| | - Xin Wang
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland
- Faculty of Biological and Environmental Sciences and Viikki Plant Science Centre, Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki 00014, Finland
| | - Ari Pekka Mähönen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland
- Faculty of Biological and Environmental Sciences and Viikki Plant Science Centre, Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki 00014, Finland
| | - Niko Geldner
- Department of Plant Molecular Biology, University of Lausanne, Lausanne 1015, Switzerland
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Batystová K, Synek L, Klejchová M, Janková Drdová E, Sabol P, Potocký M, Žárský V, Hála M. Diversification of SEC15a and SEC15b isoforms of an exocyst subunit in seed plants is manifested in their specific roles in Arabidopsis sporophyte and male gametophyte. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:1382-1396. [PMID: 35306706 DOI: 10.1111/tpj.15744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
The exocyst complex is an octameric evolutionarily conserved tethering complex engaged in the regulation of polarized secretion in eukaryotic cells. Here, we focus on the systematic comparison of two isoforms of the SEC15 exocyst subunit, SEC15a and SEC15b. We infer that SEC15 gene duplication and diversification occurred in the common ancestor of seed plants (Spermatophytes). In Arabidopsis, SEC15a represents the main SEC15 isoform in the male gametophyte, and localizes to the pollen tube tip at the plasma membrane. Although pollen tubes of sec15a mutants are impaired, sporophytes show no phenotypic deviations. Conversely, SEC15b is the dominant isoform in the sporophyte and localizes to the plasma membrane in root and leaf cells. Loss-of-function sec15b mutants exhibit retarded elongation of hypocotyls and root hairs, a loss of apical dominance, dwarfed plant stature and reduced seed coat mucilage formation. Surprisingly, the sec15b mutants also exhibit compromised pollen tube elongation in vitro, despite its very low expression in pollen, suggesting a non-redundant role for the SEC15b isoform there. In pollen tubes, SEC15b localizes to distinct cytoplasmic structures. Reciprocally to this, SEC15a also functions in the sporophyte, where it accumulates at plasmodesmata. Importantly, although overexpressed SEC15a could fully complement the sec15b phenotypic deviations in the sporophyte, the pollen-specific overexpression of SEC15b was unable to fully compensate for the loss of SEC15a function in pollen. We conclude that the SEC15a and SEC15b isoforms evolved in seed plants, with SEC15a functioning mostly in pollen and SEC15b functioning mostly in the sporophyte.
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Affiliation(s)
- Klára Batystová
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, Prague, CZ-16502, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Vinicna 5, Charles University, Prague, CZ-12844, Czech Republic
| | - Lukáš Synek
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, Prague, CZ-16502, Czech Republic
| | - Martina Klejchová
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, Prague, CZ-16502, Czech Republic
| | - Edita Janková Drdová
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, Prague, CZ-16502, Czech Republic
| | - Peter Sabol
- Department of Experimental Plant Biology, Faculty of Science, Vinicna 5, Charles University, Prague, CZ-12844, Czech Republic
| | - Martin Potocký
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, Prague, CZ-16502, Czech Republic
| | - Viktor Žárský
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, Prague, CZ-16502, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Vinicna 5, Charles University, Prague, CZ-12844, Czech Republic
| | - Michal Hála
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, Prague, CZ-16502, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Vinicna 5, Charles University, Prague, CZ-12844, Czech Republic
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10
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Dahhan DA, Reynolds GD, Cárdenas JJ, Eeckhout D, Johnson A, Yperman K, Kaufmann WA, Vang N, Yan X, Hwang I, Heese A, De Jaeger G, Friml J, Van Damme D, Pan J, Bednarek SY. Proteomic characterization of isolated Arabidopsis clathrin-coated vesicles reveals evolutionarily conserved and plant-specific components. THE PLANT CELL 2022; 34:2150-2173. [PMID: 35218346 PMCID: PMC9134090 DOI: 10.1093/plcell/koac071] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/22/2022] [Indexed: 05/26/2023]
Abstract
In eukaryotes, clathrin-coated vesicles (CCVs) facilitate the internalization of material from the cell surface as well as the movement of cargo in post-Golgi trafficking pathways. This diversity of functions is partially provided by multiple monomeric and multimeric clathrin adaptor complexes that provide compartment and cargo selectivity. The adaptor-protein assembly polypeptide-1 (AP-1) complex operates as part of the secretory pathway at the trans-Golgi network (TGN), while the AP-2 complex and the TPLATE complex jointly operate at the plasma membrane to execute clathrin-mediated endocytosis. Key to our further understanding of clathrin-mediated trafficking in plants will be the comprehensive identification and characterization of the network of evolutionarily conserved and plant-specific core and accessory machinery involved in the formation and targeting of CCVs. To facilitate these studies, we have analyzed the proteome of enriched TGN/early endosome-derived and endocytic CCVs isolated from dividing and expanding suspension-cultured Arabidopsis (Arabidopsis thaliana) cells. Tandem mass spectrometry analysis results were validated by differential chemical labeling experiments to identify proteins co-enriching with CCVs. Proteins enriched in CCVs included previously characterized CCV components and cargos such as the vacuolar sorting receptors in addition to conserved and plant-specific components whose function in clathrin-mediated trafficking has not been previously defined. Notably, in addition to AP-1 and AP-2, all subunits of the AP-4 complex, but not AP-3 or AP-5, were found to be in high abundance in the CCV proteome. The association of AP-4 with suspension-cultured Arabidopsis CCVs is further supported via additional biochemical data.
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Affiliation(s)
| | | | - Jessica J Cárdenas
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Dominique Eeckhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Alexander Johnson
- Institute of Science and Technology (IST Austria), Klosterneuburg 3400, Austria
| | | | - Walter A Kaufmann
- Institute of Science and Technology (IST Austria), Klosterneuburg 3400, Austria
| | - Nou Vang
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Xu Yan
- College Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science & Technology, Pohang 37673, Korea
| | - Antje Heese
- Division of Biochemistry, Interdisciplinary Plant Group, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Jiří Friml
- Institute of Science and Technology (IST Austria), Klosterneuburg 3400, Austria
| | - Daniël Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Jianwei Pan
- College Life Sciences, Lanzhou University, Lanzhou 730000, China
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11
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Dahhan DA, Reynolds GD, Cárdenas JJ, Eeckhout D, Johnson A, Yperman K, Kaufmann WA, Vang N, Yan X, Hwang I, Heese A, De Jaeger G, Friml J, Van Damme D, Pan J, Bednarek SY. Proteomic characterization of isolated Arabidopsis clathrin-coated vesicles reveals evolutionarily conserved and plant-specific components. THE PLANT CELL 2022; 34:2150-2173. [PMID: 35218346 DOI: 10.1101/2021.09.16.460678] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/22/2022] [Indexed: 05/26/2023]
Abstract
In eukaryotes, clathrin-coated vesicles (CCVs) facilitate the internalization of material from the cell surface as well as the movement of cargo in post-Golgi trafficking pathways. This diversity of functions is partially provided by multiple monomeric and multimeric clathrin adaptor complexes that provide compartment and cargo selectivity. The adaptor-protein assembly polypeptide-1 (AP-1) complex operates as part of the secretory pathway at the trans-Golgi network (TGN), while the AP-2 complex and the TPLATE complex jointly operate at the plasma membrane to execute clathrin-mediated endocytosis. Key to our further understanding of clathrin-mediated trafficking in plants will be the comprehensive identification and characterization of the network of evolutionarily conserved and plant-specific core and accessory machinery involved in the formation and targeting of CCVs. To facilitate these studies, we have analyzed the proteome of enriched TGN/early endosome-derived and endocytic CCVs isolated from dividing and expanding suspension-cultured Arabidopsis (Arabidopsis thaliana) cells. Tandem mass spectrometry analysis results were validated by differential chemical labeling experiments to identify proteins co-enriching with CCVs. Proteins enriched in CCVs included previously characterized CCV components and cargos such as the vacuolar sorting receptors in addition to conserved and plant-specific components whose function in clathrin-mediated trafficking has not been previously defined. Notably, in addition to AP-1 and AP-2, all subunits of the AP-4 complex, but not AP-3 or AP-5, were found to be in high abundance in the CCV proteome. The association of AP-4 with suspension-cultured Arabidopsis CCVs is further supported via additional biochemical data.
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Affiliation(s)
- Dana A Dahhan
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Gregory D Reynolds
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Jessica J Cárdenas
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Dominique Eeckhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Alexander Johnson
- Institute of Science and Technology (IST Austria), Klosterneuburg 3400, Austria
| | - Klaas Yperman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Walter A Kaufmann
- Institute of Science and Technology (IST Austria), Klosterneuburg 3400, Austria
| | - Nou Vang
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Xu Yan
- College Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science & Technology, Pohang 37673, Korea
| | - Antje Heese
- Division of Biochemistry, Interdisciplinary Plant Group, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Jiří Friml
- Institute of Science and Technology (IST Austria), Klosterneuburg 3400, Austria
| | - Daniël Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Jianwei Pan
- College Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Sebastian Y Bednarek
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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12
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Acidic and Alkaline Conditions Affect the Growth of Tree Peony Plants via Altering Photosynthetic Characteristics, Limiting Nutrient Assimilation, and Impairing ROS Balance. Int J Mol Sci 2022; 23:ijms23095094. [PMID: 35563483 PMCID: PMC9099645 DOI: 10.3390/ijms23095094] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/26/2022] [Accepted: 05/02/2022] [Indexed: 12/04/2022] Open
Abstract
Exposure to acidic and alkaline conditions were found to cause the excess accumulation of reactive oxygen species in tree peony, thereby causing damage and inhibiting plant growth and development. The activities of antioxidant enzymes were also found to be significantly up-regulated, especially under alkaline conditions; this explained why tree peony is better adapted to alkaline than to acidic conditions. Through pairwise comparisons, 144 differentially expressed genes (DEGs) associated with plant growth, photosynthesis, and stress were identified. The DEGs related to stress were up-regulated, whereas the remaining DEGs were almost all down-regulated after acid and alkaline treatments. The nutrient assimilation was greatly inhibited. Chlorophyll synthesis genes were suppressed, and chlorophyll content was reduced. The development and structures of stomata and chloroplasts and the transcription of related genes were also influenced. Among photosynthesis-related DEGs, electron transport chains were the most sensitive. The suppressed expression of photosynthesis genes and the reduced light-harvesting capacity, together with the impairment of chloroplasts and stomata, finally led to a sharp decrease in the net photosynthetic rate. Carbohydrate accumulation and plant biomass were also reduced. The present study provides a theoretical basis for the response mechanisms of tree peony to adverse pH conditions and enriches knowledge of plant adaptation to alkaline conditions.
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13
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Wu D, Guo J, Zhang Q, Shi S, Guan W, Zhou C, Chen R, Du B, Zhu L, He G. Necessity of rice resistance to planthoppers for OsEXO70H3 regulating SAMSL excretion and lignin deposition in cell walls. THE NEW PHYTOLOGIST 2022; 234:1031-1046. [PMID: 35119102 PMCID: PMC9306520 DOI: 10.1111/nph.18012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
The planthopper resistance gene Bph6 encodes a protein that interacts with OsEXO70E1. EXO70 forms a family of paralogues in rice. We hypothesized that the EXO70-dependent trafficking pathway affects the excretion of resistance-related proteins, thus impacting plant resistance to planthoppers. Here, we further explored the function of EXO70 members in rice resistance against planthoppers. We used the yeast two-hybrid and co-immunoprecipitation assays to identify proteins that play roles in Bph6-mediated planthopper resistance. The functions of the identified proteins were characterized via gene transformation, plant resistance evaluation, insect performance, cell excretion observation and cell wall component analyses. We discovered that another EXO70 member, OsEXO70H3, interacted with BPH6 and functioned in cell excretion and in Bph6-mediated planthopper resistance. We further found that OsEXO70H3 interacted with an S-adenosylmethionine synthetase-like protein (SAMSL) and increased the delivery of SAMSL outside the cells. The functional impairment of OsEXO70H3 and SAMSL reduced the lignin content and the planthopper resistance level of rice plants. Our results suggest that OsEXO70H3 may recruit SAMSL and help its excretion to the apoplast where it may be involved in lignin deposition in cell walls, thus contributing to rice resistance to planthoppers.
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Affiliation(s)
- Di Wu
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Jianping Guo
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Qian Zhang
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Shaojie Shi
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Wei Guan
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Cong Zhou
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Rongzhi Chen
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Bo Du
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Lili Zhu
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
| | - Guangcun He
- State Key Laboratory of Hybrid RiceCollege of Life SciencesWuhan UniversityWuhan430072China
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14
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Yang G, Chen BX, Chen T, Chen JH, Lin XY, Yue XL, An LZ, Zhang H. BYPASS1-LIKE regulates lateral root initiation via exocytic vesicular trafficking-mediated PIN recycling in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:965-978. [PMID: 35249253 DOI: 10.1111/jipb.13243] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
Auxin and auxin-mediated signaling pathways are known to regulate lateral root development. Although exocytic vesicle trafficking plays an important role in recycling the PIN-FORMED (PIN) auxin efflux carriers and in polar auxin transport during lateral root formation, the mechanistic details of these processes are not well understood. Here, we demonstrate that BYPASS1-LIKE (B1L) regulates lateral root initiation via exocytic vesicular trafficking-mediated PIN recycling in Arabidopsis thaliana. b1l mutants contained significantly more lateral roots than the wild type, primarily due to increased lateral root primordium initiation. Furthermore, the auxin signal was stronger in stage I lateral root primordia of b1l than in those of the wild type. Treatment with exogenous auxin and an auxin transport inhibitor indicated that the lateral root phenotype of b1l could be attributed to higher auxin levels and that B1L regulates auxin efflux. Indeed, compared to the wild type, C-terminally green fluorescent protein-tagged PIN1 and PIN3 accumulated at higher levels in b1l lateral root primordia. B1L interacted with the exocyst, and b1l showed defective PIN exocytosis. These observations indicate that B1L interacts with the exocyst to regulate PIN-mediated polar auxin transport and lateral root initiation in Arabidopsis.
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Affiliation(s)
- Gang Yang
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Bi-Xia Chen
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Tao Chen
- College of Life Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China
| | - Jia-Hui Chen
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xiang-Yu Lin
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xiu-Le Yue
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Li-Zhe An
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
- School of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Hua Zhang
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
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15
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Arabidopsis exocyst subunit SEC6 is involved in cell plate formation during Microgametogenesis. Biochem Biophys Res Commun 2022; 598:100-106. [DOI: 10.1016/j.bbrc.2022.01.092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 11/18/2022]
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16
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Pang L, Ma Z, Zhang X, Huang Y, Li R, Miao Y, Li R. The small GTPase RABA2a recruits SNARE proteins to regulate the secretory pathway in parallel with the exocyst complex in Arabidopsis. MOLECULAR PLANT 2022; 15:398-418. [PMID: 34798312 DOI: 10.1016/j.molp.2021.11.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/24/2021] [Accepted: 11/12/2021] [Indexed: 05/22/2023]
Abstract
Delivery of proteins to the plasma membrane occurs via secretion, which requires tethering, docking, priming, and fusion of vesicles. In yeast and mammalian cells, an evolutionarily conserved RAB GTPase activation cascade functions together with the exocyst and SNARE proteins to coordinate vesicle transport with fusion at the plasma membrane. However, it is unclear whether this is the case in plants. In this study, we show that the small GTPase RABA2a recruits and interacts with the VAMP721/722-SYP121-SNAP33 SNARE ternary complex for membrane fusion. Through immunoprecipitation coupled with mass spectrometry analysis followed by the validatation with a series of biochemical assays, we identified the SNARE proteins VAMP721 and SYP121 as the interactors and downstream effectors of RABA2a. Further expreiments showed that RABA2a interacts with all members of the SNARE complex in its GTP-bound form and modulates the assembly of the VAMP721/722-SYP121-SNAP33 SNARE ternary complex. Intriguingly, we did not observe the interaction of the exocyst subunits with either RABA2a or theSNARE proteins in several different experiments. Neither RABA2a inactivation affects the subcellular localization or assembly of the exocystnor the exocyst subunit mutant exo84b shows the disrupted RABA2a-SNARE association or SNARE assembly, suggesting that the RABA2a-SNARE- and exocyst-mediated secretory pathways are largely independent. Consistently, our live imaging experiments reveal that the two sets of proteins follow non-overlapping trafficking routes, and genetic and cell biologyanalyses indicate that the two pathways select different cargos. Finally, we demonstrate that the plant-specific RABA2a-SNARE pathway is essential for the maintenance of potassium homeostasis in Arabisopsis seedlings. Collectively, our findings imply that higher plants might have generated different endomembrane sorting pathways during evolution and may enable the highly conserved endomembrane proteins to participate in plant-specific trafficking mechanisms for adaptation to the changing environment.
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Affiliation(s)
- Lei Pang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhiming Ma
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Xi Zhang
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Yuanzhi Huang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Ruili Li
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Ruixi Li
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
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17
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Zhou D, Chen C, Jin Z, Chen J, Lin S, Lyu T, Liu D, Xiong X, Cao J, Huang L. Transcript Profiling Analysis and ncRNAs' Identification of Male-Sterile Systems of Brassica campestris Reveal New Insights Into the Mechanism Underlying Anther and Pollen Development. FRONTIERS IN PLANT SCIENCE 2022; 13:806865. [PMID: 35211139 PMCID: PMC8861278 DOI: 10.3389/fpls.2022.806865] [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: 11/01/2021] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
Male-sterile mutants are useful materials to study the anther and pollen development. Here, whole transcriptome sequencing was performed for inflorescences in three sterile lines of Chinese cabbage (Brassica campestris L. ssp. chinensis Makino, syn. B. rapa ssp. chinensis), the genic male-sterile line (A line), the Polima cytoplasmic male-sterile (CMS) line (P line), and the Ogura CMS line (O line) along with their maintainer line (B line). In total, 7,136 differentially expressed genes (DEGs), 361 differentially expressed long non-coding RNAs (lncRNAs) (DELs), 56 differentially expressed microRNAs (miRNAs) (DEMs) were selected out. Specific regulatory networks related to anther cell differentiation, meiosis cytokinesis, pollen wall formation, and tapetum development were constructed based on the abortion characteristics of male-sterile lines. Candidate genes and lncRNAs related to cell differentiation were identified in sporocyteless P line, sixteen of which were common to the DEGs in Arabidopsis spl/nzz mutant. Genes and lncRNAs concerning cell plate formation were selected in A line that is defected in meiosis cytokinesis. Also, the orthologs of pollen wall formation and tapetum development genes in Arabidopsis showed distinct expression patterns in the three different sterile lines. Among 361 DELs, 35 were predicted to interact with miRNAs, including 28 targets, 47 endogenous target mimics, and five precursors for miRNAs. Two lncRNAs were further proved to be functional precursors for bra-miR156 and bra-miR5718, respectively. Overexpression of bra-miR5718HG in B. campestris slowed down the growth of pollen tubes, caused shorter pollen tubes, and ultimately affected the seed set. Our study provides new insights into molecular regulation especially the ncRNA interaction during pollen development in Brassica crops.
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Affiliation(s)
- Dong Zhou
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
| | - Caizhi Chen
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
| | - Zongmin Jin
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
| | - Jingwen Chen
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
| | - Sue Lin
- Institute of Life Sciences, Wenzhou University, Wenzhou, China
| | - Tao Lyu
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
| | - Dandan Liu
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
| | - Xinpeng Xiong
- College of Bioengineering, Jingchu University of Technology, Jingmen, China
| | - Jiashu Cao
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
| | - Li Huang
- Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, China
- Hainan Institute of Zhejiang University, Sanya, China
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18
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Ortmannová J, Sekereš J, Kulich I, Šantrůček J, Dobrev P, Žárský V, Pečenková T. Arabidopsis EXO70B2 exocyst subunit contributes to papillae and encasement formation in antifungal defence. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:742-755. [PMID: 34664667 DOI: 10.1093/jxb/erab457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
In the reaction to non-adapted Blumeria graminis f. sp. hordei (Bgh), Arabidopsis thaliana leaf epidermal cells deposit cell wall reinforcements called papillae or seal fungal haustoria in encasements, both of which involve intensive exocytosis. A plant syntaxin, SYP121/PEN1, has been found to be of key importance for the timely formation of papillae, and the vesicle tethering complex exocyst subunit EXO70B2 has been found to contribute to their morphology. Here, we identify a specific role for the EXO70B2-containing exocyst complex in the papillae membrane domains important for callose deposition and GFP-SYP121 delivery to the focal attack sites, as well as its contribution to encasement formation. The mRuby2-EXO70B2 co-localizes with the exocyst core subunit SEC6 and GFP-SYP121 in the membrane domain of papillae, and EXO70B2 and SYP121 proteins have the capacity to directly interact. The exo70B2/syp121 double mutant produces a reduced number of papillae and haustorial encasements in response to Bgh, indicating an additive role of the exocyst in SYP121-coordinated non-host resistance. In summary, we report cooperation between the plant exocyst and a SNARE protein in penetration resistance against non-adapted fungal pathogens.
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Affiliation(s)
- Jitka Ortmannová
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Juraj Sekereš
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Ivan Kulich
- Laboratory of Cell Morphogenesis, Department of Experimental Plant Biology, Charles University in Prague, Faculty of Science, Viničná 5, 128 44, Prague 2, Czech Republic
| | - Jiří Šantrůček
- Laboratory of Applied Proteomics, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic
| | - Petre Dobrev
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Viktor Žárský
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, 165 02, Prague 6, Czech Republic
- Laboratory of Cell Morphogenesis, Department of Experimental Plant Biology, Charles University in Prague, Faculty of Science, Viničná 5, 128 44, Prague 2, Czech Republic
| | - Tamara Pečenková
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, 165 02, Prague 6, Czech Republic
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19
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Gu Y, Rasmussen CG. Cell biology of primary cell wall synthesis in plants. THE PLANT CELL 2022; 34:103-128. [PMID: 34613413 PMCID: PMC8774047 DOI: 10.1093/plcell/koab249] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/01/2021] [Indexed: 05/07/2023]
Abstract
Building a complex structure such as the cell wall, with many individual parts that need to be assembled correctly from distinct sources within the cell, is a well-orchestrated process. Additional complexity is required to mediate dynamic responses to environmental and developmental cues. Enzymes, sugars, and other cell wall components are constantly and actively transported to and from the plasma membrane during diffuse growth. Cell wall components are transported in vesicles on cytoskeletal tracks composed of microtubules and actin filaments. Many of these components, and additional proteins, vesicles, and lipids are trafficked to and from the cell plate during cytokinesis. In this review, we first discuss how the cytoskeleton is initially organized to add new cell wall material or to build a new cell wall, focusing on similarities during these processes. Next, we discuss how polysaccharides and enzymes that build the cell wall are trafficked to the correct location by motor proteins and through other interactions with the cytoskeleton. Finally, we discuss some of the special features of newly formed cell walls generated during cytokinesis.
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Affiliation(s)
- Ying Gu
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Carolyn G Rasmussen
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, University of California, Riverside, California 92521
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20
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Automated Time-Lapse Imaging and Manipulation of Cell Divisions in Arabidopsis Roots by Vertical-Stage Confocal Microscopy. Methods Mol Biol 2021. [PMID: 34705235 DOI: 10.1007/978-1-0716-1744-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The analysis of dynamic cellular processes such as plant cytokinesis stands and falls with live-cell time-lapse confocal imaging. Conventional approaches to time-lapse imaging of cell division in Arabidopsis root tips are tedious and have low throughput. Here, we describe a protocol for long-term time-lapse simultaneous imaging of multiple root tips on a vertical-stage confocal microscope with automated root tracking. We also provide modifications of the basic protocol to implement this imaging method in the analysis of genetic, pharmacological or laser ablation wounding-mediated experimental manipulations. Our method dramatically improves the efficiency of cell division time-lapse imaging by increasing the throughput, while reducing the person-hour requirements of such experiments.
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21
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Zhu YQ, Qiu L, Liu LL, Luo L, Han XP, Zhai YH, Wang WJ, Ren MZ, Xing YD. Identification and Comprehensive Structural and Functional Analyses of the EXO70 Gene Family in Cotton. Genes (Basel) 2021; 12:genes12101594. [PMID: 34680988 PMCID: PMC8536163 DOI: 10.3390/genes12101594] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/30/2021] [Accepted: 10/02/2021] [Indexed: 11/24/2022] Open
Abstract
The EXO70 gene is a vital component of the exocytosis complex and participates in biological processes ranging from plant cell division to polar growth. There are many EXO70 genes in plants and their functions are extensive, but little is known about the EXO70 gene family in cotton. Here, we analyzed four cotton sequence databases, identified 165 EXO70 genes, and divided them into eight subgroups (EXO70A–EXO70H) based on their phylogenetic relationships. EXO70A had the most exons (≥11), whereas the other seven each had only one or two exons. Hence, EXO70A may have many important functions. The 84 EXO70 genes in Asian and upland cotton were expressed in the roots, stems, leaves, flowers, fibers, and/or ovules. Full-length GhEXO70A1-A cDNA was homologously cloned from upland cotton (Gossypium hirsutum, G. hirsutum). Subcellular analysis revealed that GhEXO70A1-A protein was localized to the plasma membrane. A yeast two-hybrid assay revealed that GhEXO70A1-A interacted with GhEXO84A, GhEXO84B, and GhEXO84C. GhEXO70A1-A silencing significantly altered over 4000 genes and changed several signaling pathways related to metabolism. Thus, the EXO70 gene plays critical roles in the physiological functions of cotton.
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Affiliation(s)
- Ya-Qian Zhu
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Lu Qiu
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Lu-Lu Liu
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Lei Luo
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Xin-Pei Han
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Yao-Hua Zhai
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Wen-Jing Wang
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
| | - Mao-Zhi Ren
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China
- Correspondence: (M.-Z.R.); (Y.-D.X.)
| | - Ya-Di Xing
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China; (Y.-Q.Z.); (L.Q.); (L.-L.L.); (L.L.); (X.-P.H.); (Y.-H.Z.); (W.-J.W.)
- Correspondence: (M.-Z.R.); (Y.-D.X.)
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22
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Plasma membrane phospholipid signature recruits the plant exocyst complex via the EXO70A1 subunit. Proc Natl Acad Sci U S A 2021; 118:2105287118. [PMID: 34470819 DOI: 10.1073/pnas.2105287118] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Polarized exocytosis is essential for many vital processes in eukaryotic cells, where secretory vesicles are targeted to distinct plasma membrane domains characterized by their specific lipid-protein composition. Heterooctameric protein complex exocyst facilitates the vesicle tethering to a target membrane and is a principal cell polarity regulator in eukaryotes. The architecture and molecular details of plant exocyst and its membrane recruitment have remained elusive. Here, we show that the plant exocyst consists of two modules formed by SEC3-SEC5-SEC6-SEC8 and SEC10-SEC15-EXO70-EXO84 subunits, respectively, documenting the evolutionarily conserved architecture within eukaryotes. In contrast to yeast and mammals, the two modules are linked by a plant-specific SEC3-EXO70 interaction, and plant EXO70 functionally dominates over SEC3 in the exocyst recruitment to the plasma membrane. Using an interdisciplinary approach, we found that the C-terminal part of EXO70A1, the canonical EXO70 isoform in Arabidopsis, is critical for this process. In contrast to yeast and animal cells, the EXO70A1 interaction with the plasma membrane is mediated by multiple anionic phospholipids uniquely contributing to the plant plasma membrane identity. We identified several evolutionary conserved EXO70 lysine residues and experimentally proved their importance for the EXO70A1-phospholipid interactions. Collectively, our work has uncovered plant-specific features of the exocyst complex and emphasized the importance of the specific protein-lipid code for the recruitment of peripheral membrane proteins.
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23
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Zhang W, Huang L, Zhang C, Staiger CJ. Arabidopsis myosin XIK interacts with the exocyst complex to facilitate vesicle tethering during exocytosis. THE PLANT CELL 2021; 33:2454-2478. [PMID: 33871640 PMCID: PMC8364239 DOI: 10.1093/plcell/koab116] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 04/13/2021] [Indexed: 05/17/2023]
Abstract
Myosin motors are essential players in secretory vesicle trafficking and exocytosis in yeast and mammalian cells; however, similar roles in plants remain a matter for debate, at least for diffusely growing cells. Here, we demonstrate that Arabidopsis (Arabidopsis thaliana) myosin XIK, via its globular tail domain (GTD), participates in the vesicle tethering step of exocytosis through direct interactions with the exocyst complex. Specifically, myosin XIK GTD bound directly to several exocyst subunits in vitro and functional fluorescently tagged XIK colocalized with multiple exocyst subunits at plasma membrane (PM)-associated stationary foci. Moreover, genetic and pharmacological inhibition of myosin XI activity reduced the rate of appearance and lifetime of stationary exocyst complexes at the PM. By tracking single exocytosis events of cellulose synthase (CESA) complexes with high spatiotemporal resolution imaging and pair-wise colocalization of myosin XIK, exocyst subunits, and CESA6, we demonstrated that XIK associates with secretory vesicles earlier than exocyst and is required for the efficient localization and normal dynamic behavior of exocyst complex at the PM tethering site. This study reveals an important functional role for myosin XI in secretion and provides insights about the dynamic regulation of exocytosis in plants.
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Affiliation(s)
- Weiwei Zhang
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
| | - Lei Huang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Chunhua Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
- Center for Plant Biology, College of Agriculture, Purdue University, West Lafayette, Indiana 47907, USA
| | - Christopher J. Staiger
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
- Center for Plant Biology, College of Agriculture, Purdue University, West Lafayette, Indiana 47907, USA
- Author for correspondence:
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24
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Marković V, Kulich I, Žárský V. Functional Specialization within the EXO70 Gene Family in Arabidopsis. Int J Mol Sci 2021; 22:7595. [PMID: 34299214 PMCID: PMC8303320 DOI: 10.3390/ijms22147595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 01/20/2023] Open
Abstract
Localized delivery of plasma-membrane and cell-wall components is a crucial process for plant cell growth. One of the regulators of secretory-vesicle targeting is the exocyst tethering complex. The exocyst mediates first interaction between transport vesicles and the target membrane before their fusion is performed by SNARE proteins. In land plants, genes encoding the EXO70 exocyst subunit underwent an extreme proliferation with 23 paralogs present in the Arabidopsis (Arabidopsis thaliana) genome. These paralogs often acquired specialized functions during evolution. Here, we analyzed functional divergence of selected EXO70 paralogs in Arabidopsis. Performing a systematic cross-complementation analysis of exo70a1 and exo70b1 mutants, we found that EXO70A1 was functionally substituted only by its closest paralog, EXO70A2. In contrast, none of the EXO70 isoforms tested were able to substitute EXO70B1, including its closest relative, EXO70B2, pointing to a unique function of this isoform. The presented results document a high degree of functional specialization within the EXO70 gene family in land plants.
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Affiliation(s)
- Vedrana Marković
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 12844 Prague, Czech Republic; (V.M.); (V.Ž.)
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, 16502 Prague, Czech Republic
| | - Ivan Kulich
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 12844 Prague, Czech Republic; (V.M.); (V.Ž.)
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 12844 Prague, Czech Republic; (V.M.); (V.Ž.)
- Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, 16502 Prague, Czech Republic
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25
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Zhao J, Zhang H, Zhang X, Wang Z, Niu Y, Chen Y, Sun L, Wang H, Wang X, Xiao J. The Exocyst Complex Subunit EXO70E1-V From Haynaldia villosa Interacts With Wheat Powdery Mildew Resistance Gene CMPG1-V. FRONTIERS IN PLANT SCIENCE 2021; 12:652337. [PMID: 34305961 PMCID: PMC8295898 DOI: 10.3389/fpls.2021.652337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 06/08/2021] [Indexed: 06/03/2023]
Abstract
EXO70 belongs to the exocyst complex subunit that plays a critical role in regulating plant cell polarity establishment and defense response. A previous study proved that the E3 ligase CMPG1-V from Haynaldia villosa, a diploid wheat relative, positively regulates the resistance to wheat powdery mildew (Pm), caused by fungus Blumeria graminis f.sp tritici (Bgt). In this study, a member of EXO70 superfamily named EXO70E1-V was isolated from H. villosa, and EXO70E1-V interacted with CMPG1-V were shown by yeast two-hybrid (Y2H), pull-down assay, bimolecular fluorescence complementation (BiFC) assay, and luciferase complementation imaging (LCI) assay. It is localized in various subcellular organs, i.e., plasma membrane (PM) and endoplasmic reticulum. Co-expression of EXO70E1-V and CMPG1-V showed dot-like structure fluorescence signals that were mainly in PM and nucleus. Expression of EXO70E1-V was relatively higher in leaf and was significantly induced by Bgt infection and exogenous application of hormones such as salicylic acid. Transient or stable overexpression of EXO70E1-V could not enhance/decrease the Pm resistance level, suggesting overexpression of EXO70E1-V alone has no impact on Pm resistance in wheat.
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Affiliation(s)
- Jia Zhao
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
- The Laboratory of Seed Science and Technology, Guangdong Key Laboratory of Plant Molecular Breeding, Guangdong Laboratory of Lingnan Modern Agriculture, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
| | - Heng Zhang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xu Zhang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Zongkuan Wang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Ying Niu
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Yiming Chen
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Li Sun
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Haiyan Wang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Xiue Wang
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Jin Xiao
- State Key Lab of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
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26
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Lin Y, Zeng Y, Zhu Y, Shen J, Ye H, Jiang L. Plant Rho GTPase signaling promotes autophagy. MOLECULAR PLANT 2021; 14:905-920. [PMID: 33794369 DOI: 10.1016/j.molp.2021.03.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/27/2021] [Accepted: 03/25/2021] [Indexed: 05/06/2023]
Abstract
The roles of Rho family guanosine triphosphatases (GTPases) of plants (ROPs) in modulating plant growth and development have been well characterized. However, little is known about the roles of ROP signaling pathways in regulating plant autophagy and autophagosome formation. In this study, we identify a unique ROP signaling mechanism, which mediates developmental to autophagic transition under stress conditions in the model plant Arabidopsis. Loss-of-function mutants of ROP8 showed stress-induced hypersensitive phenotypes and compromised autophagic flux. Similar to other ROPs in the ROP/RAC family, ROP8 exhibits both plasma membrane and cytosolic punctate localization patterns. Upon autophagic induction, active ROP8 puncta colocalize with autophagosomal markers and are degraded inside the vacuole. In human cells, RalB, an RAS subfamily GTPase, engages its effector Exo84 for autophagosome assembly. However, a RalB counterpart is missing in the plant lineage. Intriguingly, we discovered that plant ROP8 promotes autophagy via its downstream effector Sec5. Live-cell super-resolution imaging showed that ROP8 and Sec5 reside on phagophores for autophagosome formation. Taken together, our findings highlight a previously unappreciated role of an ROP8-Sec5 signaling axis in autophagy promotion, providing new insights into how plants utilize versatile ROP signaling networks to coordinate developmental and autophagic responses depending on environmental changes.
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Affiliation(s)
- Youshun Lin
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
| | - Yonglun Zeng
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Ying Zhu
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Jinbo Shen
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Hao Ye
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; Institute of Plant Molecular Biology and Agricultural Biotechnology, CUHK, Hong Kong, China; CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, N.T., Shenzhen, Hong Kong, 518057, China.
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27
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Belteton SA, Li W, Yanagisawa M, Hatam FA, Quinn MI, Szymanski MK, Marley MW, Turner JA, Szymanski DB. Real-time conversion of tissue-scale mechanical forces into an interdigitated growth pattern. NATURE PLANTS 2021; 7:826-841. [PMID: 34112988 DOI: 10.1038/s41477-021-00931-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
The leaf epidermis is a dynamic biomechanical shell that integrates growth across spatial scales to influence organ morphology. Pavement cells, the fundamental unit of this tissue, morph irreversibly into highly lobed cells that drive planar leaf expansion. Here, we define how tissue-scale cell wall tensile forces and the microtubule-cellulose synthase systems dictate the patterns of interdigitated growth in real time. A morphologically potent subset of cortical microtubules span the periclinal and anticlinal cell faces to pattern cellulose fibres that generate a patch of anisotropic wall. The subsequent local polarized growth is mechanically coupled to the adjacent cell via a pectin-rich middle lamella, and this drives lobe formation. Finite element pavement cell models revealed cell wall tensile stress as an upstream patterning element that links cell- and tissue-scale biomechanical parameters to interdigitated growth. Cell lobing in leaves is evolutionarily conserved, occurs in multiple cell types and is associated with important agronomic traits. Our general mechanistic models of lobe formation provide a foundation to analyse the cellular basis of leaf morphology and function.
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Affiliation(s)
- Samuel A Belteton
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Wenlong Li
- Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | | | - Faezeh A Hatam
- Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Madeline I Quinn
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Margaret K Szymanski
- Department of Biochemistry, Indiana University Bloomington, Bloomington, IN, USA
| | - Matthew W Marley
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Joseph A Turner
- Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Daniel B Szymanski
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA.
- Biological Sciences, Purdue University, West Lafayette, IN, USA.
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28
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Brejšková L, Hála M, Rawat A, Soukupová H, Cvrčková F, Charlot F, Nogué F, Haluška S, Žárský V. SEC6 exocyst subunit contributes to multiple steps of growth and development of Physcomitrella (Physcomitrium patens). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:831-843. [PMID: 33599020 DOI: 10.1111/tpj.15205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 12/18/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Spatially directed cell division and expansion is important for plant growth and morphogenesis and relies on cooperation between the cytoskeleton and the secretory pathway. The phylogenetically conserved octameric complex exocyst mediates exocytotic vesicle tethering at the plasma membrane. Unlike other exocyst subunits of land plants, the core exocyst subunit SEC6 exists as a single paralog in Physcomitrium patens and Arabidopsis thaliana genomes. Arabidopsis SEC6 (AtSEC6) loss-of-function (LOF) mutation causes male gametophytic lethality. Our attempts to inactivate the P. patens SEC6 gene, PpSEC6, using targeted gene replacement produced two independent partial LOF ('weak allele') mutants via perturbation of the PpSEC6 gene locus. These mutants exhibited the same pleiotropic developmental defects: protonema with dominant chloronema stage; diminished caulonemal filament elongation rate; and failure in post-initiation gametophore development. Mutant gametophore buds, mostly initiated from chloronema cells, exhibited disordered cell file organization and cross-wall perforations, resulting in arrested development at the eight- to 10-cell stage. Complementation of both sec6 moss mutant lines by both PpSEC6 and AtSEC6 cDNA rescued gametophore development, including sexual organ differentiation. However, regular sporophyte formation and viable spore production were recovered only by the expression of PpSEC6, whereas the AtSEC6 complementants were only rarely fertile, indicating moss-specific SEC6 functions.
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Affiliation(s)
- Lucie Brejšková
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 165 02, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Prague 2, Czech Republic
| | - Michal Hála
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 165 02, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Prague 2, Czech Republic
| | - Anamika Rawat
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 165 02, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Prague 2, Czech Republic
| | - Hana Soukupová
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 165 02, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Prague 2, Czech Republic
| | - Florence Charlot
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, 78000, France
| | - Fabien Nogué
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, 78000, France
| | - Samuel Haluška
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 165 02, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Prague 2, Czech Republic
| | - Viktor Žárský
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, Prague 6, 165 02, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Prague 2, Czech Republic
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29
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Xing Y, Wang N, Zhang T, Zhang Q, Du D, Chen X, Lu X, Zhang Y, Zhu M, Liu M, Sang X, Li Y, Ling Y, He G. SHORT-ROOT 1 is critical to cell division and tracheary element development in rice roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1179-1191. [PMID: 33231904 DOI: 10.1111/tpj.15095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 06/11/2023]
Abstract
The exocyst is a key factor in vesicle transport and is involved in cell secretion, cell growth, cell division and other cytological processes in eukaryotes. EXO70 is the key exocyst subunit. We obtained a gene, SHORT-ROOT 1 (SR1), through map-based cloning and genetic complementation. SR1 is a conserved protein with an EXO70 domain in plants. SR1 mutation affected the whole root-development process: producing shorter radicles, adventitious roots and lateral roots, and demonstrating abnormal xylem development, resulting in dwarfing and reduced water potential and moisture content. SR1 was largely expressed in the roots, but only in developing root meristems and tracheary elements. The shortness of the sr1 mutant roots was caused by the presence of fewer meristem cells. The in situ histone H4 expression patterns confirmed that cell proliferation during root development was impaired. Tracheary element dysplasia was caused by marked decreases in the inner diameters of and distances between the perforations of adjacent tracheary elements. The membrane transport of sr1 mutants was blocked, affecting cell division in the root apical region and the development of root tracheary elements. The study of SR1 will deepen our understanding of the function of EXO70 genes in Oryza sativa (rice) and guide future studies on the molecular mechanisms involved in plant root development.
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Affiliation(s)
- Yadi Xing
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
- Agricultural College, Zhengzhou University, Zhengzhou, 450001, China
| | - Nan Wang
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Tianquan Zhang
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Qiuli Zhang
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Dan Du
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Xinlong Chen
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Xin Lu
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Yingying Zhang
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Maodi Zhu
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Mingming Liu
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Xianchun Sang
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Yunfeng Li
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Yinghua Ling
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Guanghua He
- Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
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30
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Orr RG, Furt F, Warner EL, Agar EM, Garbarino JM, Cabral SE, Dubuke ML, Butt AM, Munson M, Vidali L. Rab-E and its interaction with myosin XI are essential for polarised cell growth. THE NEW PHYTOLOGIST 2021; 229:1924-1936. [PMID: 33098085 PMCID: PMC8168425 DOI: 10.1111/nph.17023] [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: 05/02/2020] [Accepted: 10/12/2020] [Indexed: 05/07/2023]
Abstract
The fundamental process of polarised exocytosis requires the interconnected activity of molecular motors trafficking vesicular cargo within a dynamic cytoskeletal network. In plants, few mechanistic details are known about how molecular motors, such as myosin XI, associate with their secretory cargo to support the ubiquitous processes of polarised growth and cell division. Live-cell imaging coupled with targeted gene knockouts and a high-throughput RNAi assay enabled the first characterisation of the loss of Rab-E function. Yeast two-hybrid and subsequent in silico structural prediction uncovered a specific interaction between Rab-E and myosin XI that is conserved between P. patens and A. thaliana. Rab-E co-localises with myosin XI at sites of active exocytosis, and at the growing tip both proteins are spatiotemporally coupled. Rab-E is required for normal plant growth in P. patens and the rab-E and myosin XI phenotypes are rescued by A. thaliana's Rab-E1c and myosin XI-K/E, respectively. Both PpMyoXI and AtMyoXI-K interact with PpRabE14, and the interaction is specifically mediated by PpMyoXI residue V1422. This interaction is required for polarised growth. Our results suggest that the interaction of Rab-E and myosin XI is a conserved feature of polarised growth in plants.
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Affiliation(s)
- Robert G Orr
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Fabienne Furt
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Erin L Warner
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Erin M Agar
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Jennifer M Garbarino
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Sarah E Cabral
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Michelle L Dubuke
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Allison M Butt
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - Mary Munson
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Luis Vidali
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
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31
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Saccomanno A, Potocký M, Pejchar P, Hála M, Shikata H, Schwechheimer C, Žárský V. Regulation of Exocyst Function in Pollen Tube Growth by Phosphorylation of Exocyst Subunit EXO70C2. FRONTIERS IN PLANT SCIENCE 2021; 11:609600. [PMID: 33519861 PMCID: PMC7840542 DOI: 10.3389/fpls.2020.609600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/22/2020] [Indexed: 06/12/2023]
Abstract
Exocyst is a heterooctameric protein complex crucial for the tethering of secretory vesicles to the plasma membrane during exocytosis. Compared to other eukaryotes, exocyst subunit EXO70 is represented by many isoforms in land plants whose cell biological and biological roles, as well as modes of regulation remain largely unknown. Here, we present data on the phospho-regulation of exocyst isoform EXO70C2, which we previously identified as a putative negative regulator of exocyst function in pollen tube growth. A comprehensive phosphoproteomic analysis revealed phosphorylation of EXO70C2 at multiple sites. We have now performed localization and functional studies of phospho-dead and phospho-mimetic variants of Arabidopsis EXO70C2 in transiently transformed tobacco pollen tubes and stably transformed Arabidopsis wild type and exo70C2 mutant plants. Our data reveal a dose-dependent effect of AtEXO70C2 overexpression on pollen tube growth rate and cellular architecture. We show that changes of the AtEXO70C2 phosphorylation status lead to distinct outcomes in wild type and exo70c2 mutant cells, suggesting a complex regulatory pattern. On the other side, phosphorylation does not affect the cytoplasmic localization of AtEXO70C2 or its interaction with putative secretion inhibitor ROH1 in the yeast two-hybrid system.
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Affiliation(s)
- Antonietta Saccomanno
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Martin Potocký
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Přemysl Pejchar
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Michal Hála
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Hiromasa Shikata
- Plant Systems Biology, Technische Universität München, Freising, Germany
| | | | - Viktor Žárský
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
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32
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Marković V, Cvrčková F, Potocký M, Kulich I, Pejchar P, Kollárová E, Synek L, Žárský V. EXO70A2 Is Critical for Exocyst Complex Function in Pollen Development. PLANT PHYSIOLOGY 2020; 184:1823-1839. [PMID: 33051268 PMCID: PMC7723085 DOI: 10.1104/pp.19.01340] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 10/01/2020] [Indexed: 05/15/2023]
Abstract
Pollen development, pollen grain germination, and pollen tube elongation are crucial biological processes in angiosperm plants that need precise regulation to deliver sperm cells to ovules for fertilization. Highly polarized secretion at a growing pollen tube tip requires the exocyst tethering complex responsible for specific targeting of secretory vesicles to the plasma membrane. Here, we demonstrate that Arabidopsis (Arabidopsis thaliana) EXO70A2 (At5g52340) is the main exocyst EXO70 isoform in the male gametophyte, governing the conventional secretory function of the exocyst, analogous to EXO70A1 (At5g03540) in the sporophyte. Our analysis of a CRISPR-generated exo70a2 mutant revealed that EXO70A2 is essential for efficient pollen maturation, pollen grain germination, and pollen tube growth. GFP:EXO70A2 was localized to the nucleus and cytoplasm in developing pollen grains and later to the apical domain in growing pollen tube tips characterized by intensive exocytosis. Moreover, EXO70A2 could substitute for EXO70A1 function in the sporophyte, but not vice versa, indicating partial functional redundancy of these two closely related isoforms and higher specificity of EXO70A2 for pollen development-related processes. Phylogenetic analysis revealed that the ancient duplication of EXO70A, one of which is always highly expressed in pollen, occurred independently in monocots and dicots. In summary, EXO70A2 is a crucial component of the exocyst complex in Arabidopsis pollen that is required for efficient plant sexual reproduction.
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Affiliation(s)
- Vedrana Marković
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12844 Prague 2, Czech Republic
- Institute of Experimental Botany, Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12844 Prague 2, Czech Republic
| | - Martin Potocký
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12844 Prague 2, Czech Republic
- Institute of Experimental Botany, Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Ivan Kulich
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12844 Prague 2, Czech Republic
| | - Přemysl Pejchar
- Institute of Experimental Botany, Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Eva Kollárová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12844 Prague 2, Czech Republic
| | - Lukáš Synek
- Institute of Experimental Botany, Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12844 Prague 2, Czech Republic
- Institute of Experimental Botany, Czech Academy of Sciences, 16502 Prague 6, Czech Republic
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33
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Acheampong AK, Shanks C, Cheng CY, Schaller GE, Dagdas Y, Kieber JJ. EXO70D isoforms mediate selective autophagic degradation of type-A ARR proteins to regulate cytokinin sensitivity. Proc Natl Acad Sci U S A 2020; 117:27034-27043. [PMID: 33051300 PMCID: PMC7604425 DOI: 10.1073/pnas.2013161117] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The phytohormone cytokinin influences many aspects of plant growth and development, several of which also involve the cellular process of autophagy, including leaf senescence, nutrient remobilization, and developmental transitions. The Arabidopsis type-A response regulators (type-A ARR) are negative regulators of cytokinin signaling that are transcriptionally induced in response to cytokinin. Here, we describe a mechanistic link between cytokinin signaling and autophagy, demonstrating that plants modulate cytokinin sensitivity through autophagic regulation of type-A ARR proteins. Type-A ARR proteins were degraded by autophagy in an AUTOPHAGY-RELATED (ATG)5-dependent manner, and this degradation is promoted by phosphorylation on a conserved aspartate in the receiver domain of the type-A ARRs. EXO70D family members interacted with type-A ARR proteins, likely in a phosphorylation-dependent manner, and recruited them to autophagosomes via interaction of the EXO70D AIM with the core autophagy protein, ATG8. Consistently, loss-of-function exo70D1,2,3 mutants exhibited compromised targeting of type-A ARRs to autophagic vesicles, have elevated levels of type-A ARR proteins, and are hyposensitive to cytokinin. Disruption of both type-A ARRs and EXO70D1,2,3 compromised survival in carbon-deficient conditions, suggesting interaction between autophagy and cytokinin responsiveness in response to stress. These results indicate that the EXO70D proteins act as selective autophagy receptors to target type-A ARR cargos for autophagic degradation, demonstrating modulation of cytokinin signaling by selective autophagy.
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Affiliation(s)
| | - Carly Shanks
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Chia-Yi Cheng
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - G Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
| | - Yasin Dagdas
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Joseph J Kieber
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599;
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34
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Larson ER, Ortmannová J, Donald NA, Alvim J, Blatt MR, Žárský V. Synergy among Exocyst and SNARE Interactions Identifies a Functional Hierarchy in Secretion during Vegetative Growth. THE PLANT CELL 2020; 32:2951-2963. [PMID: 32699172 PMCID: PMC7474273 DOI: 10.1105/tpc.20.00280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/23/2020] [Accepted: 07/20/2020] [Indexed: 05/28/2023]
Abstract
Vesicle exocytosis underpins signaling and development in plants and is vital for cell expansion. Vesicle tethering and fusion are thought to occur sequentially, with tethering mediated by the exocyst and fusion driven by assembly of soluble NSF attachment protein receptor (SNARE) proteins from the vesicle membrane (R-SNAREs or vesicle-associated membrane proteins [VAMPs]) and the target membrane (Q-SNAREs). Interactions between exocyst and SNARE protein complexes are known, but their functional consequences remain largely unexplored. We now identify a hierarchy of interactions leading to secretion in Arabidopsis (Arabidopsis thaliana). Mating-based split-ubiquitin screens and in vivo Förster resonance energy transfer analyses showed that exocyst EXO70 subunits bind preferentially to cognate plasma membrane SNAREs, notably SYP121 and VAMP721. The exo70A1 mutant affected SNARE distribution and suppressed vesicle traffic similarly to the dominant-negative truncated protein SYP121ΔC, which blocks secretion at the plasma membrane. These phenotypes are consistent with the epistasis of exo70A1 in the exo70A1 syp121 double mutant, which shows decreased growth similar to exo70A1 single mutants. However, the exo70A1 vamp721 mutant showed a strong, synergy, suppressing growth and cell expansion beyond the phenotypic sum of the two single mutants. These data are best explained by a hierarchy of SNARE recruitment to the exocyst at the plasma membrane, dominated by the R-SNARE and plausibly with the VAMP721 longin domain as a nexus for binding.
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Affiliation(s)
- Emily R Larson
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Jitka Ortmannová
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, 165 02 Prague 6, Czech Republic
| | - Naomi A Donald
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Jonas Alvim
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Viktor Žárský
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, 165 02 Prague 6, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 128 44 Prague 2, Czech Republic
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35
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Scholz P, Anstatt J, Krawczyk HE, Ischebeck T. Signalling Pinpointed to the Tip: The Complex Regulatory Network That Allows Pollen Tube Growth. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1098. [PMID: 32859043 PMCID: PMC7569787 DOI: 10.3390/plants9091098] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/18/2020] [Accepted: 08/23/2020] [Indexed: 12/13/2022]
Abstract
Plants display a complex life cycle, alternating between haploid and diploid generations. During fertilisation, the haploid sperm cells are delivered to the female gametophyte by pollen tubes, specialised structures elongating by tip growth, which is based on an equilibrium between cell wall-reinforcing processes and turgor-driven expansion. One important factor of this equilibrium is the rate of pectin secretion mediated and regulated by factors including the exocyst complex and small G proteins. Critically important are also non-proteinaceous molecules comprising protons, calcium ions, reactive oxygen species (ROS), and signalling lipids. Among the latter, phosphatidylinositol 4,5-bisphosphate and the kinases involved in its formation have been assigned important functions. The negatively charged headgroup of this lipid serves as an interaction point at the apical plasma membrane for partners such as the exocyst complex, thereby polarising the cell and its secretion processes. Another important signalling lipid is phosphatidic acid (PA), that can either be formed by the combination of phospholipases C and diacylglycerol kinases or by phospholipases D. It further fine-tunes pollen tube growth, for example by regulating ROS formation. How the individual signalling cues are intertwined or how external guidance cues are integrated to facilitate directional growth remain open questions.
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Affiliation(s)
- Patricia Scholz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Justus-von-Liebig Weg 11, D-37077 Goettingen, Germany; (J.A.); (H.E.K.)
| | | | | | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Justus-von-Liebig Weg 11, D-37077 Goettingen, Germany; (J.A.); (H.E.K.)
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36
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Pečenková T, Potocká A, Potocký M, Ortmannová J, Drs M, Janková Drdová E, Pejchar P, Synek L, Soukupová H, Žárský V, Cvrčková F. Redundant and Diversified Roles Among Selected Arabidopsis thaliana EXO70 Paralogs During Biotic Stress Responses. FRONTIERS IN PLANT SCIENCE 2020; 11:960. [PMID: 32676093 PMCID: PMC7333677 DOI: 10.3389/fpls.2020.00960] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 06/11/2020] [Indexed: 05/28/2023]
Abstract
The heterooctameric vesicle-tethering complex exocyst is important for plant development, growth, and immunity. Multiple paralogs exist for most subunits of this complex; especially the membrane-interacting subunit EXO70 underwent extensive amplification in land plants, suggesting functional specialization. Despite this specialization, most Arabidopsis exo70 mutants are viable and free of developmental defects, probably as a consequence of redundancy among isoforms. Our in silico data-mining and modeling analysis, corroborated by transcriptomic experiments, pinpointed several EXO70 paralogs to be involved in plant biotic interactions. We therefore tested corresponding single and selected double mutant combinations (for paralogs EXO70A1, B1, B2, H1, E1, and F1) in their two biologically distinct responses to Pseudomonas syringae, root hair growth stimulation and general plant susceptibility. A shift in defense responses toward either increased or decreased sensitivity was found in several double mutants compared to wild type plants or corresponding single mutants, strongly indicating both additive and compensatory effects of exo70 mutations. In addition, our experiments confirm the lipid-binding capacity of selected EXO70s, however, without the clear relatedness to predicted C-terminal lipid-binding motifs. Our analysis uncovers that there is less of functional redundancy among isoforms than we could suppose from whole sequence phylogeny and that even paralogs with overlapping expression pattern and similar membrane-binding capacity appear to have exclusive roles in plant development and biotic interactions.
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Affiliation(s)
- Tamara Pečenková
- Institute of Experimental Botany, CAS, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | | | - Martin Potocký
- Institute of Experimental Botany, CAS, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | | | - Matěj Drs
- Institute of Experimental Botany, CAS, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Edita Janková Drdová
- Institute of Experimental Botany, CAS, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Přemysl Pejchar
- Institute of Experimental Botany, CAS, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Lukáš Synek
- Institute of Experimental Botany, CAS, Prague, Czechia
| | | | - Viktor Žárský
- Institute of Experimental Botany, CAS, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
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37
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Žárský V, Sekereš J, Kubátová Z, Pečenková T, Cvrčková F. Three subfamilies of exocyst EXO70 family subunits in land plants: early divergence and ongoing functional specialization. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:49-62. [PMID: 31647563 DOI: 10.1093/jxb/erz423] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 10/10/2019] [Indexed: 05/27/2023]
Abstract
Localized delivery of plasma membrane and cell wall components is an essential process in all plant cells. The vesicle-tethering complex, the exocyst, an ancient eukaryotic hetero-octameric protein cellular module, assists in targeted delivery of exocytosis vesicles to specific plasma membrane domains. Analyses of Arabidopsis and later other land plant genomes led to the surprising prediction of multiple putative EXO70 exocyst subunit paralogues. All land plant EXO70 exocyst subunits (including those of Bryophytes) form three distinct subfamilies-EXO70.1, EXO70.2, and EXO70.3. Interestingly, while the basal well-conserved EXO70.1 subfamily consists of multiexon genes, the remaining two subfamilies contain mostly single exon genes. Published analyses as well as public transcriptomic and proteomic data clearly indicate that most cell types in plants express and also use several different EXO70 isoforms. Here we sum up recent advances in the characterization of the members of the family of plant EXO70 exocyst subunits and present evidence that members of the EXO70.2 subfamily are often recruited to non-canonical functions in plant membrane trafficking pathways. Engagement of the most evolutionarily dynamic EXO70.2 subfamily of EXO70s in biotic interactions and defence correlates well with massive proliferation and conservation of new protein variants in this subfamily.
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Affiliation(s)
- Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
- Institute of Experimental Botany, v.v.i., Czech Academy of Sciences, Rozvojová, Prague, Czech Republic
| | - Juraj Sekereš
- Institute of Experimental Botany, v.v.i., Czech Academy of Sciences, Rozvojová, Prague, Czech Republic
| | - Zdeňka Kubátová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
| | - Tamara Pečenková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
- Institute of Experimental Botany, v.v.i., Czech Academy of Sciences, Rozvojová, Prague, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
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38
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Huang L, Li X, Li Y, Yin X, Li Y, Wu B, Mo H, Liao CJ, Mengiste T, Guo W, Dai M, Zhang C. Endosidin2-14 Targets the Exocyst Complex in Plants and Fungal Pathogens to Inhibit Exocytosis. PLANT PHYSIOLOGY 2019; 180:1756-1770. [PMID: 31072814 PMCID: PMC6752926 DOI: 10.1104/pp.18.01457] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 04/29/2019] [Indexed: 05/29/2023]
Abstract
The evolutionarily conserved octameric exocyst complex tethers secretory vesicles to the site of membrane fusion during exocytosis. The plant exocyst complex functions in cell wall biosynthesis, polarized growth, stress responses, and hormone signaling. In fungal pathogens, the exocyst complex is required for growth, development, and pathogenesis. Endosidin2 (ES2) is known to inhibit exocytosis in plant and mammalian cells by targeting the EXO70 subunit of the exocyst complex. Here we show that an analog of ES2, ES2-14, targets plant and two fungal EXO70s. A lower dosage of ES2-14 than of ES2 is required to inhibit plant growth, plant exocytic trafficking, and fungal growth. ES2-14 treatments inhibit appressorium formation and reduce lesion sizes caused by Magnaporthe oryzae Inhibition of EXO70 by ES2-14 in Botrytis cinerea also reduces its virulence in Arabidopsis (Arabidopsis thaliana). Interestingly, ES2-14 did not affect EXO70 localization or transferrin recycling in mammalian cells. Overall, our results indicate that a minor change in ES2 affects its specificity in targeting EXO70s in different organisms and they demonstrate the potential of using ES2-14 to study the mechanisms of plant and fungal exocytosis and the roles of exocytosis in fungus-plant interactions.
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Affiliation(s)
- Lei Huang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, Purdue University, West Lafayette, Indiana 47907
| | - Xiaohui Li
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, Purdue University, West Lafayette, Indiana 47907
| | - Yang Li
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Xianglin Yin
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Yong Li
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Bin Wu
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Huaping Mo
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Chao-Jan Liao
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Tesfaye Mengiste
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Wei Guo
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Mingji Dai
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Chunhua Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
- Purdue Center for Plant Biology, Purdue University, West Lafayette, Indiana 47907
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39
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Shimada TL, Betsuyaku S, Inada N, Ebine K, Fujimoto M, Uemura T, Takano Y, Fukuda H, Nakano A, Ueda T. Enrichment of Phosphatidylinositol 4,5-Bisphosphate in the Extra-Invasive Hyphal Membrane Promotes Colletotrichum Infection of Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2019; 60:1514-1524. [PMID: 30989198 DOI: 10.1093/pcp/pcz058] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 04/01/2019] [Indexed: 06/09/2023]
Abstract
Pathogenic fungi from the genus Colletotrichum form invasive hyphae; the hyphae are surrounded by an extra-invasive hyphal membrane (EIHM), which is continuous with the plant plasma membrane. Although the EIHM plays a crucial role as the interface between plant and fungal cells, its precise function during Colletotrichum infection remains elusive. Here, we show that enrichment of phosphoinositides (PIs) has a crucial role in Colletotrichum infection. We observed the localization of PIs in Arabidopsis thaliana cells infected by A. thaliana-adapted Colletotrichum higginsianum (Ch), and found that phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] was extremely enriched in the EIHM during Ch infection. We also found that phosphatidylinositol 4-phosphate-5 kinase (PIP5K), which catalyzes production of PI(4,5)P2, also accumulated at the EIHM. The overexpression of PIP5K3 in A. thaliana increased hyphal invasion by Ch. An exocytic factor, EXO84b, was targeted to the EIHM during Ch infection, although endocytic factors such as CLATHRIN LIGHT CHAIN 2 and FLOTILLIN 1 did not. Intriguingly, the interfacial membranes between A. thaliana and powdery mildew- or downy mildew-causing pathogens did not accumulate PI(4,5)P2. These results suggest that Ch could modify the PI(4,5)P2 levels in the EIHM to increase the exocytic membrane/protein supply of the EIHM for successful infection. Our results also suggest that PI(4,5)P2 biosynthesis is a promising target for improved defense against Colletotrichum infection.
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Affiliation(s)
- Takashi L Shimada
- Division of Cellular Dynamics, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi, Japan
- Department of Applied Biological Chemistry, Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba, Japan
| | - Shigeyuki Betsuyaku
- Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho Kawaguchi, Saitama, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
- Present address: Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan
| | - Noriko Inada
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka, Japan
| | - Kazuo Ebine
- Division of Cellular Dynamics, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi, Japan
- Department of Basic Biology, SOKENDAI (Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Masaru Fujimoto
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Tomohiro Uemura
- Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo-ku, Tokyo, Japan
| | - Yoshitaka Takano
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, Japan
| | - Hiroo Fukuda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Akihiko Nakano
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
- Live Cell Super-resolution Live Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama, Japan
| | - Takashi Ueda
- Division of Cellular Dynamics, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi, Japan
- Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho Kawaguchi, Saitama, Japan
- Department of Basic Biology, SOKENDAI (Graduate University for Advanced Studies), Okazaki, Aichi, Japan
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40
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Rui Y, Chen Y, Yi H, Purzycki T, Puri VM, Anderson CT. Synergistic Pectin Degradation and Guard Cell Pressurization Underlie Stomatal Pore Formation. PLANT PHYSIOLOGY 2019; 180:66-77. [PMID: 30804009 PMCID: PMC6501081 DOI: 10.1104/pp.19.00135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 02/12/2019] [Indexed: 05/05/2023]
Abstract
Stomatal pores are vital for the diffusion of gasses into and out of land plants and are, therefore, gatekeepers for photosynthesis and transpiration. Although much published literature has described the intercellular signaling and transcriptional regulators involved in early stomatal development, little is known about the cellular details of the local separation between sister guard cells that give rise to the stomatal pore or how formation of this pore is achieved. Using three-dimensional (3D) time-lapse imaging, we found that stomatal pore formation in Arabidopsis (Arabidopsis thaliana) is a highly dynamic process involving pore initiation and enlargement and traverses a set of morphological milestones in 3D. Confocal imaging data revealed an enrichment of exocytic machinery, de-methyl-esterified pectic homogalacturonan (HG), and an HG-degrading enzyme at future pore sites, suggesting that both localized HG deposition and degradation might function in pore formation. By manipulating HG modification via enzymatic, chemical, and genetic perturbations in seedling cotyledons, we found that augmenting HG modification promotes pore formation, whereas preventing HG de-methyl-esterification delays pore initiation and inhibits pore enlargement. Through mechanical modeling and experimentation, we tested whether pore formation is an outcome of sister guard cells being pulled away from each other upon turgor increase. Osmotic treatment to reduce turgor pressure did not prevent pore initiation but did lessen pore enlargement. Together, these data provide evidence that HG delivery and modification, and guard cell pressurization, make functional contributions to stomatal pore initiation and enlargement.
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Affiliation(s)
- Yue Rui
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802
- Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Yintong Chen
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802
- Intercollege Graduate Degree Program in Molecular Cellular and Integrative Biosciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Hojae Yi
- Department of Agricultural and Biological Engineering, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Taylor Purzycki
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Virendra M Puri
- Department of Agricultural and Biological Engineering, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Charles T Anderson
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802
- Intercollege Graduate Degree Program in Plant Biology, Pennsylvania State University, University Park, Pennsylvania 16802
- Intercollege Graduate Degree Program in Molecular Cellular and Integrative Biosciences, Pennsylvania State University, University Park, Pennsylvania 16802
- Center for Lignocellulose Structure and Formation, Pennsylvania State University, University Park, Pennsylvania 16802
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41
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Zhang W, Cai C, Staiger CJ. Myosins XI Are Involved in Exocytosis of Cellulose Synthase Complexes. PLANT PHYSIOLOGY 2019; 179:1537-1555. [PMID: 30705068 PMCID: PMC6446754 DOI: 10.1104/pp.19.00018] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 01/20/2019] [Indexed: 05/18/2023]
Abstract
In plants, cellulose is synthesized at the cell surface by plasma membrane (PM)-localized cellulose synthase (CESA) complexes (CSCs). The molecular and cellular mechanisms that underpin delivery of CSCs to the PM, however, are poorly understood. Cortical microtubules have been shown to interact with CESA-containing compartments and mark the site for CSC delivery, but are not required for the delivery itself. Here, we demonstrate that myosin XI and the actin cytoskeleton mediate CSC delivery to the PM by coordinating the exocytosis of CESA-containing compartments. Measurement of cellulose content indicated that cellulose biosynthesis was significantly reduced in a myosin xik xi1 xi2 triple-knockout mutant. By combining genetic and pharmacological disruption of myosin activity with quantitative live-cell imaging, we observed decreased abundance of PM-localized CSCs and reduced delivery rate of CSCs in myosin-deficient cells. These phenotypes correlated with a significant increase in failed vesicle secretion events at the PM as well as an abnormal accumulation of CESA-containing compartments at the cell cortex. Through high-resolution spatiotemporal assays of cortical vesicle behavior, we identified defects in CSC vesicle tethering and fusion at the PM. Furthermore, disruption of myosin activity reduced the delivery of several other secretory markers to the PM and reduced constitutive and receptor-mediated endocytosis. These findings reveal a previously undescribed role for myosin in vesicle secretion and cellulose production at the cytoskeleton-PM-cell wall nexus.
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Affiliation(s)
- Weiwei Zhang
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-2064
| | - Chao Cai
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-2064
| | - Christopher J Staiger
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-2064
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
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42
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Zhou H, Duan H, Liu Y, Sun X, Zhao J, Lin H. Patellin protein family functions in plant development and stress response. JOURNAL OF PLANT PHYSIOLOGY 2019; 234-235:94-97. [PMID: 30690193 DOI: 10.1016/j.jplph.2019.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 05/24/2023]
Abstract
The plant patellin (PATL) proteins are yeast Sec14 protein (Sec14p)-like phosphatidylinositol transfer proteins (PITPs), which are widely distributed across the plant kingdom. The model plant Arabidopsis has six PATL members (designated as PATL1-PATL6). Accumulated evidence has indicated the involvement of Arabidopsis PATLs in various biological processes. This mini-review briefly summarizes our current knowledge on individual PATLs regarding their roles in plant development and stress tolerance regulation. The elucidation of PATLs' biological function in plants will provide new insights on plant membrane trafficking and its regulatory roles in either plant growth or environmental stress response signaling networks.
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Affiliation(s)
- Huapeng Zhou
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Hongqin Duan
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
| | - Yunhong Liu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
| | - Xia Sun
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
| | - Jinfeng Zhao
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Honghui Lin
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China.
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Janková Drdová E, Klejchová M, Janko K, Hála M, Soukupová H, Cvrčková F, Žárský V. Developmental plasticity of Arabidopsis hypocotyl is dependent on exocyst complex function. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1255-1265. [PMID: 30649396 PMCID: PMC6382343 DOI: 10.1093/jxb/erz005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 11/15/2018] [Accepted: 12/21/2018] [Indexed: 05/08/2023]
Abstract
The collet (root-hypocotyl junction) region is an important plant transition zone between soil and atmospheric environments. Despite its crucial importance for plant development, little is known about how this transition zone is specified. Here we document the involvement of the exocyst complex in this process. The exocyst, an octameric tethering complex, participates in secretion and membrane recycling and is central to numerous cellular and developmental processes, such as growth of root hairs, cell expansion, recycling of PIN auxin efflux carriers and many others. We show that dark-grown Arabidopsis mutants deficient in exocyst subunits can form a hair-bearing ectopic collet-like structure above the true collet, morphologically resembling the true collet but also retaining some characteristics of the hypocotyl. The penetrance of this phenotypic defect is significantly influenced by cultivation temperature and carbon source, and is related to a defect in auxin regulation. These observations provide new insights into the regulation of collet region formation and developmental plasticity of the hypocotyl.
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Affiliation(s)
- Edita Janková Drdová
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague 6, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague 2, Czech Republic
- Correspondence:
| | - Martina Klejchová
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague 6, Czech Republic
| | - Karel Janko
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Liběchov, Czech Republic
| | - Michal Hála
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague 6, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague 2, Czech Republic
| | - Hana Soukupová
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague 6, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague 2, Czech Republic
| | - Viktor Žárský
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague 6, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague 2, Czech Republic
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Tang H, de Keijzer J, Overdijk EJR, Sweep E, Steentjes M, Vermeer JEM, Janson ME, Ketelaar T. Exocyst subunit Sec6 is positioned by microtubule overlaps in the moss phragmoplast prior to cell plate membrane arrival. J Cell Sci 2019; 132:jcs222430. [PMID: 30635445 DOI: 10.1242/jcs.222430] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 01/02/2019] [Indexed: 12/21/2022] Open
Abstract
During plant cytokinesis a radially expanding membrane-enclosed cell plate is formed from fusing vesicles that compartmentalizes the cell in two. How fusion is spatially restricted to the site of cell plate formation is unknown. Aggregation of cell-plate membrane starts near regions of microtubule overlap within the bipolar phragmoplast apparatus of the moss Physcomitrella patens Since vesicle fusion generally requires coordination of vesicle tethering and subsequent fusion activity, we analyzed the subcellular localization of several subunits of the exocyst, a tethering complex active during plant cytokinesis. We found that the exocyst complex subunit Sec6 but not the Sec3 or Sec5 subunits localized to microtubule overlap regions in advance of cell plate construction in moss. Moreover, Sec6 exhibited a conserved physical interaction with an ortholog of the Sec1/Munc18 protein KEULE, an important regulator for cell-plate membrane vesicle fusion in Arabidopsis Recruitment of the P. patens protein KEULE and vesicles to the early cell plate was delayed upon Sec6 gene silencing. Our findings, thus, suggest that vesicle-vesicle fusion is, in part, enabled by a pool of exocyst subunits at microtubule overlaps, which is recruited independently of vesicle delivery.
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Affiliation(s)
- Han Tang
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Jeroen de Keijzer
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Elysa J R Overdijk
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Els Sweep
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Maikel Steentjes
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Joop E M Vermeer
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| | - Marcel E Janson
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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45
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Identification and Characterization of the EXO70 Gene Family in Polyploid Wheat and Related Species. Int J Mol Sci 2018; 20:ijms20010060. [PMID: 30586859 PMCID: PMC6337732 DOI: 10.3390/ijms20010060] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 12/13/2018] [Accepted: 12/21/2018] [Indexed: 12/24/2022] Open
Abstract
The EXO70 gene family is involved in different biological processes in plants, ranging from plant polar growth to plant immunity. To date, analysis of the EXO70 gene family has been limited in Triticeae species, e.g., hexaploidy Triticum aestivum and its ancestral/related species. By in silico analysis of multiple Triticeae sequence databases, a total of 200 EXO70 members were identified. By homologue cloning approaches, 15 full-length cDNA of EXO70s were cloned from diploid Haynaldia villosa. Phylogenetic relationship analysis of 215 EXO70 members classified them into three groups (EXO70.1, EXO70.2, and EXO70.3) and nine subgroups (EXO70A to EXO70I). The distribution of most EXO70 genes among different species/sub-genomes were collinear, implying their orthologous relationship. The EXO70A subgroup has the most introns (at least five introns), while the remaining seven subgroups have only one intron on average. The expression profiling of EXO70 genes from wheat revealed that 40 wheat EXO70 genes were expressed in at least one tissue (leaf, stem, or root), of which 25 wheat EXO70 genes were in response to at least one biotic stress (stripe rust or powdery mildew) or abiotic stress (drought or heat). Subcellular localization analysis showed that ten EXO70-V proteins had distinct plasma membrane localization, EXO70I1-V showed a distinctive spotted pattern on the membrane. The 15 EXO70-V genes were differentially expressed in three tissue. Apart from EXO70D2-V, the remaining EXO70-V genes were in response to at least one stress (flg22, chitin, powdery mildew, drought, NaCl, heat, or cold) or phytohormones (salicylic acid, methyl jasmonate, ethephon, or abscisic acid) and hydrogen peroxide treatments. This research provides a genome-wide glimpse of the Triticeae EXO70 gene family and those up- or downregulated genes require further validation of their biological roles in response to biotic/abiotic stresses.
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46
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Smertenko A. Phragmoplast expansion: the four-stroke engine that powers plant cytokinesis. CURRENT OPINION IN PLANT BIOLOGY 2018; 46:130-137. [PMID: 30072118 DOI: 10.1016/j.pbi.2018.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/28/2018] [Accepted: 07/13/2018] [Indexed: 05/21/2023]
Abstract
The phragmoplast is a plant-specific secretory module that partitions daughter cells during cytokinesis by constructing a cell plate from membranes and oligosaccharides. The cell plate is typically a long structure, which requires the phragmoplast to expand to complete cytokinesis. The phragmoplast expands by coordinating microtubule dynamics with membrane trafficking. Each step in phragmoplast expansion involves the establishment of anti-parallel microtubule overlaps that are enriched with the protein MAP65, which recruits cytokinetic vesicles through interaction with the tethering factor, TRAPPII. Cell plate assembly triggers dissolution of the anti-parallel overlaps and stabilization of microtubule plus ends through association with the cell plate assembly machinery. This opinion article discusses processes that drive phragmoplast expansion as well as highlights key questions that remain for better understanding its role in plant cell division.
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Affiliation(s)
- Andrei Smertenko
- Institute of Biological Chemistry, College of Human, Agricultural, and Natural Resource Sciences, Washington State University, Pullman, WA 99164, USA.
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47
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Ravikumar R, Kalbfuß N, Gendre D, Steiner A, Altmann M, Altmann S, Rybak K, Edelmann H, Stephan F, Lampe M, Facher E, Wanner G, Falter-Braun P, Bhalerao RP, Assaad FF. Independent yet overlapping pathways ensure the robustness and responsiveness of trans-Golgi network functions in Arabidopsis. Development 2018; 145:145/21/dev169201. [DOI: 10.1242/dev.169201] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/02/2018] [Indexed: 01/21/2023]
Abstract
ABSTRACT
The trans-Golgi-network (TGN) has essential housekeeping functions in secretion, endocytosis and protein sorting, but also more specialized functions in plant development. How the robustness of basal TGN function is ensured while specialized functions are differentially regulated is poorly understood. Here, we investigate two key regulators of TGN structure and function, ECHIDNA and the Transport Protein Particle II (TRAPPII) tethering complex. An analysis of physical, network and genetic interactions suggests that two network communities are implicated in TGN function and that ECHIDNA and TRAPPII belong to distinct yet overlapping pathways. Whereas ECHIDNA and TRAPPII colocalized at the TGN in interphase cells, their localization diverged in dividing cells. Moreover, ECHIDNA and TRAPPII localization patterns were mutually independent. TGN structure, endocytosis and sorting decisions were differentially impacted in echidna and trappii mutants. Our analyses point to a partitioning of specialized TGN functions, with ECHIDNA being required for cell elongation and TRAPPII for cytokinesis. Two independent pathways able to compensate for each other might contribute to the robustness of TGN housekeeping functions and to the responsiveness and fine tuning of its specialized functions.
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Affiliation(s)
- Raksha Ravikumar
- Plant Science Department, Botany, Technische Universität München, 85354 Freising, Germany
| | - Nils Kalbfuß
- Plant Science Department, Botany, Technische Universität München, 85354 Freising, Germany
| | - Delphine Gendre
- Umeå Plant Science Centre, Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden
| | - Alexander Steiner
- Plant Science Department, Botany, Technische Universität München, 85354 Freising, Germany
| | - Melina Altmann
- Institute of Network Biology (INET), Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), 85764 Neuherberg, Germany
| | - Stefan Altmann
- Institute of Network Biology (INET), Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), 85764 Neuherberg, Germany
| | - Katarzyna Rybak
- Plant Science Department, Botany, Technische Universität München, 85354 Freising, Germany
| | - Holger Edelmann
- Plant Science Department, Botany, Technische Universität München, 85354 Freising, Germany
| | - Friederike Stephan
- Plant Science Department, Botany, Technische Universität München, 85354 Freising, Germany
| | - Marko Lampe
- Advanced Light Microscopy Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Eva Facher
- Systematic Botany and Mycology, Faculty of Biology, Dept. I Ludwig-Maximilians-Universität, 80638 Munich, Germany
| | - Gerhard Wanner
- Faculty of Biology, Dept. I, Ludwig-Maximillians Universität, 82152 Planegg-Martinsried, Germany
| | - Pascal Falter-Braun
- Institute of Network Biology (INET), Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), 85764 Neuherberg, Germany
- Faculty of Biology, Microbe-Host-Interactions, Ludwig-Maximilians-Universität (LMU) München, 82152 Planegg-Martinsried, Germany
| | - Rishikesh P. Bhalerao
- Umeå Plant Science Centre, Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden
| | - Farhah F. Assaad
- Plant Science Department, Botany, Technische Universität München, 85354 Freising, Germany
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48
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Chen HW, Persson S, Grebe M, McFarlane HE. Cellulose synthesis during cell plate assembly. PHYSIOLOGIA PLANTARUM 2018; 164:17-26. [PMID: 29418000 DOI: 10.1111/ppl.12703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/12/2018] [Accepted: 02/04/2018] [Indexed: 05/07/2023]
Abstract
The plant cell wall surrounds and protects the cells. To divide, plant cells must synthesize a new cell wall to separate the two daughter cells. The cell plate is a transient polysaccharide-based compartment that grows between daughter cells and gives rise to the new cell wall. Cellulose constitutes a key component of the cell wall, and mutants with defects in cellulose synthesis commonly share phenotypes with cytokinesis-defective mutants. However, despite the importance of cellulose in the cell plate and the daughter cell wall, many open questions remain regarding the timing and regulation of cellulose synthesis during cell division. These questions represent a critical gap in our knowledge of cell plate assembly, cell division and growth. Here, we review what is known about cellulose synthesis at the cell plate and in the newly formed cross-wall and pose key questions about the molecular mechanisms that govern these processes. We further provide an outlook discussing outstanding questions and possible future directions for this field of research.
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Affiliation(s)
- Hsiang-Wen Chen
- School of Biosciences, University of Melbourne, Melbourne, Victoria 3010, Australia
- Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, Potsdam D-14476, Germany
| | - Staffan Persson
- School of Biosciences, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Markus Grebe
- Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, Potsdam D-14476, Germany
| | - Heather E McFarlane
- School of Biosciences, University of Melbourne, Melbourne, Victoria 3010, Australia
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Cole RA, Peremyslov VV, Van Why S, Moussaoui I, Ketter A, Cool R, Moreno MA, Vejlupkova Z, Dolja VV, Fowler JE. A broadly conserved NERD genetically interacts with the exocyst to affect root growth and cell expansion. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3625-3637. [PMID: 29722827 PMCID: PMC6022600 DOI: 10.1093/jxb/ery162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 04/24/2018] [Indexed: 05/10/2023]
Abstract
The exocyst, a conserved, octameric protein complex, helps mediate secretion at the plasma membrane, facilitating specific developmental processes that include control of root meristem size, cell elongation, and tip growth. A genetic screen for second-site enhancers in Arabidopsis identified NEW ENHANCER of ROOT DWARFISM1 (NERD1) as an exocyst interactor. Mutations in NERD1 combined with weak exocyst mutations in SEC8 and EXO70A1 result in a synergistic reduction in root growth. Alone, nerd1 alleles modestly reduce primary root growth, both by shortening the root meristem and by reducing cell elongation, but also result in a slight increase in root hair length, bulging, and rupture. NERD1 was identified molecularly as At3g51050, which encodes a transmembrane protein of unknown function that is broadly conserved throughout the Archaeplastida. A functional NERD1-GFP fusion localizes to the Golgi, in a pattern distinct from the plasma membrane-localized exocyst, arguing against a direct NERD1-exocyst interaction. Structural modeling suggests the majority of the protein is positioned in the lumen, in a β-propeller-like structure that has some similarity to proteins that bind polysaccharides. We suggest that NERD1 interacts with the exocyst indirectly, possibly affecting polysaccharides destined for the cell wall, and influencing cell wall characteristics in a developmentally distinct manner.
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Affiliation(s)
- Rex A Cole
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Valera V Peremyslov
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Savannah Van Why
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Ibrahim Moussaoui
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Ann Ketter
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Renee Cool
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Matthew Andres Moreno
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Zuzana Vejlupkova
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Valerian V Dolja
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - John E Fowler
- Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
- Correspondence:
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50
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Functional diversification of Arabidopsis SEC1-related SM proteins in cytokinetic and secretory membrane fusion. Proc Natl Acad Sci U S A 2018; 115:6309-6314. [PMID: 29844177 DOI: 10.1073/pnas.1722611115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sec1/Munc18 (SM) proteins contribute to membrane fusion by interacting with Qa-SNAREs or nascent trans-SNARE complexes. Gymnosperms and the basal angiosperm Amborella have only a single SEC1 gene related to the KEULE gene in Arabidopsis However, the genomes of most angiosperms including Arabidopsis encode three SEC1-related SM proteins of which only KEULE has been functionally characterized as interacting with the cytokinesis-specific Qa-SNARE KNOLLE during cell-plate formation. Here we analyze the closest paralog of KEULE named SEC1B. In contrast to the cytokinesis defects of keule mutants, sec1b mutants are homozygous viable. However, the keule sec1b double mutant was nearly gametophytically lethal, displaying collapsed pollen grains, which suggests substantial overlap between SEC1B and KEULE functions in secretion-dependent growth. SEC1B had a strong preference for interaction with the evolutionarily ancient Qa-SNARE SYP132 involved in secretion and cytokinesis, whereas KEULE interacted with both KNOLLE and SYP132. This differential interaction with Qa-SNAREs is likely conferred by domains 1 and 2a of the two SM proteins. Comparative analysis of all four possible combinations of the relevant SEC1 Qa-SNARE double mutants revealed that in cytokinesis, the interaction of SEC1B with KNOLLE plays no role, whereas the interaction of KEULE with KNOLLE is prevalent and functionally as important as the interactions of both SEC1B and KEU with SYP132 together. Our results suggest that functional diversification of the two SEC1-related SM proteins during angiosperm evolution resulted in enhanced interaction of SEC1B with Qa-SNARE SYP132, and thus a predominant role of SEC1B in secretion.
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