1
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Müller S. Update: on selected ROP cell polarity mechanisms in plant cell morphogenesis. PLANT PHYSIOLOGY 2023; 193:26-41. [PMID: 37070572 DOI: 10.1093/plphys/kiad229] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/20/2023] [Accepted: 04/02/2023] [Indexed: 06/19/2023]
Abstract
The unequal (asymmetric) distribution of cell structures and proteins within a cell is designated as cell polarity. Cell polarity is a crucial prerequisite for morphogenetic processes such as oriented cell division and directed cell expansion. Rho-related GTPase from plants (ROPs) are required for cellular morphogenesis through the reorganization of the cytoskeleton and vesicle transport in various tissues. Here, I review recent advances in ROP-dependent tip growth, vesicle transport, and tip architecture. I report on the regulatory mechanisms of ROP upstream regulators found in different cell types. It appears that these regulators assemble in nanodomains with specific lipid compositions and recruit ROPs for activation in a stimulus-dependent manner. Current models link mechanosensing/mechanotransduction to ROP polarity signaling involved in feedback mechanisms via the cytoskeleton. Finally, I discuss ROP signaling components that are upregulated by tissue-specific transcription factors and exhibit specific localization patterns during cell division, clearly suggesting ROP signaling in division plane alignment.
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Affiliation(s)
- Sabine Müller
- Department of Biology, Friedrich-Alexander University of Erlangen-Nuremberg, 91058 Erlangen, Germany
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2
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Goring DR, Bosch M, Franklin-Tong VE. Contrasting self-recognition rejection systems for self-incompatibility in Brassica and Papaver. Curr Biol 2023; 33:R530-R542. [PMID: 37279687 DOI: 10.1016/j.cub.2023.03.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Self-incompatibility (SI) plays a pivotal role in whether self-pollen is accepted or rejected. Most SI systems employ two tightly linked loci encoding highly polymorphic pollen (male) and pistil (female) S-determinants that control whether self-pollination is successful or not. In recent years our knowledge of the signalling networks and cellular mechanisms involved has improved considerably, providing an important contribution to our understanding of the diverse mechanisms used by plant cells to recognise each other and elicit responses. Here, we compare and contrast two important SI systems employed in the Brassicaceae and Papaveraceae. Both use 'self-recognition' systems, but their genetic control and S-determinants are quite different. We describe the current knowledge about the receptors and ligands, and the downstream signals and responses utilized to prevent self-seed set. What emerges is a common theme involving the initiation of destructive pathways that block the key processes that are required for compatible pollen-pistil interactions.
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Affiliation(s)
- Daphne R Goring
- Department of Cell & Systems Biology, University of Toronto, Toronto M5S 3B2, Canada
| | - Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3EB, Wales, UK
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3
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Weng X, Shen Y, Jiang L, Zhao L, Wang H. Spatiotemporal organization and correlation of tip-focused exocytosis and endocytosis in regulating pollen tube tip growth. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 330:111633. [PMID: 36775070 DOI: 10.1016/j.plantsci.2023.111633] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/09/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Pollen tube polar growth is a key cellular process during plant fertilization and is regulated by tip-focused exocytosis and endocytosis. However, the spatiotemporal dynamics and localizations of apical exocytosis and endocytosis in the tip region are still a matter of debate. Here, we use a refined spinning-disk confocal microscope coupled with fluorescence recovery after photobleaching for sustained live imaging and quantitative analysis of rapid vesicular activities in growing pollen tube tips. We traced and analyzed the occurrence site of exocytic plasma membrane-targeting of Arabidopsis secretory carrier membrane protein 4 and its subsequent endocytosis in tobacco pollen tube tips. We demonstrated that the pollen tube apex is the site for both vesicle polar exocytic fusion and endocytosis to take place. In addition, we disrupted either tip-focused exocytosis or endocytosis and found that their dynamic activities are closely correlated with one another basing on the spatial organization of actin fringe. Collectively, our findings attempt to propose a new exocytosis and endocytosis-coordinated yin-yang working model underlying the apical membrane organization and dynamics during pollen tube tip growth.
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Affiliation(s)
- Xun Weng
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Yifan Shen
- Utahloy International School of Guangzhou, Guangzhou 510642, 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 & Agricultural Biotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Lifeng Zhao
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
| | - Hao Wang
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
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4
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Zhang Z, Li K, Zhang H, Wang Q, Zhao L, Liu J, Chen H. A single silk- and multiple pollen-expressed PMEs at the Ga1 locus modulate maize unilateral cross-incompatibility. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:1344-1355. [PMID: 36621865 DOI: 10.1111/jipb.13445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/06/2023] [Indexed: 05/13/2023]
Abstract
The Gametophyte factor1 (Ga1) locus in maize confers unilateral cross-incompatibility (UCI), and it is controlled by both pollen and silk-specific determinants. Although the Ga1 locus has been reported for more than a century and is widely utilized in maize breeding programs, only the pollen-specific ZmGa1P has been shown to function as a male determinant; thus, the genomic structure of the Ga1 locus and all the determinants that control UCI at this locus have not yet been fully characterized. Here, we used map-based cloning to confirm the determinants of UCI at the Ga1 locus and maize pan-genome sequence data to characterize the genomic structure of the Ga1 locus. The Ga1 locus comprises one silk-expressed pectin methylesterase gene (PME) (ZmGa1F) and eight pollen-expressed PMEs (ZmGa1P and ZmGa1PL1-7). Knockout of ZmGa1F in Ga1/Ga1 lines leads to the complete loss of the female barrier function. The expression of individual ZmGa1PL genes in a ga1/ga1 background endows ga1 pollen with the ability to overcome the female barrier of the Ga1 locus. These findings, combined with genomic data and genetic analyses, indicate that the Ga1 locus is modulated by a single female determinant and multiple male determinants, which are tightly linked. The results of this study provide valuable insights into the genomic structure of the Ga2 and Tcb1 loci and will aid applications of these loci in maize breeding programs.
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Affiliation(s)
- Zhaogui Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China
| | - Kai Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huairen Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China
| | - Qiuxia Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Zhao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China
| | - Juan Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China
| | - Huabang Chen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China
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5
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Fan T, Fan Y, Yang Y, Qian D, Niu Y, An L, Xiang Y. SEC1A and SEC6 synergistically regulate pollen tube polar growth. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023. [PMID: 36951316 DOI: 10.1111/jipb.13486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/21/2023] [Indexed: 06/18/2023]
Abstract
Pollen tube polar growth is a key physiological activity for angiosperms to complete double fertilization, which is highly dependent on the transport of polar substances mediated by secretory vesicles. The exocyst and Sec1/Munc18 (SM) proteins are involved in the regulation of the tethering and fusion of vesicles and plasma membranes, but the molecular mechanism by which they regulate pollen tube polar growth is still unclear. In this study, we found that loss of function of SEC1A, a member of the SM protein family in Arabidopsis thaliana, resulted in reducing pollen tube growth and a significant increase in pollen tube width. SEC1A was diffusely distributed in the pollen tube cytoplasm, and was more concentrated at the tip of the pollen tube. Through co-immunoprecipitation-mass spectrometry screening, protein interaction analysis and in vivo microscopy, we found that SEC1A interacted with the exocyst subunit SEC6, and they mutually affected the distribution and secretion rate at the tip of the pollen tube. Meanwhile, the functional loss of SEC1A and SEC6 significantly affected the distribution of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex member SYP125 at the tip of the pollen tube, and led to the disorder of pollen tube cell wall components. Genetic analysis revealed that the pollen tube-related phenotype of the sec1a sec6 double mutant was significantly enhanced compared with their respective single mutants. Therefore, we speculated that SEC1A and SEC6 cooperatively regulate the fusion of secretory vesicles and plasma membranes in pollen tubes, thereby affecting the length and the width of pollen tubes.
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Affiliation(s)
- Tingting Fan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yuemin Fan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yang Yang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Dong Qian
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yue Niu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Lizhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
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6
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Weng X, Wang H. Apical vesicles: Social networking at the pollen tube tip. REPRODUCTION AND BREEDING 2022. [DOI: 10.1016/j.repbre.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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7
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Kastner C, Wagner VC, Fratini M, Dobritzsch D, Fuszard M, Heilmann M, Heilmann I. The pollen-specific class VIII-myosin ATM2 from Arabidopsis thaliana associates with the plasma membrane through a polybasic region binding anionic phospholipids. Biochimie 2022; 203:65-76. [DOI: 10.1016/j.biochi.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/04/2022] [Accepted: 10/06/2022] [Indexed: 11/02/2022]
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8
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Synthetic growth by self-lubricated photopolymerization and extrusion inspired by plants and fungi. Proc Natl Acad Sci U S A 2022; 119:e2201776119. [PMID: 35943987 PMCID: PMC9388119 DOI: 10.1073/pnas.2201776119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Growth in nature often couples material generation and actuation, offering an intriguing paradigm for the marriage of materials science and robotics. Inspired by the growth of plants and fungi, a new approach for synthetic materials growth was developed based on simultaneous self-lubricated photopolymerization and extrusion. This strategy enables a new continuous method for light-based fabrication of profiled parts not possible with state-of-the-art three-dimensional (3D) printing or other methods. We exploit this materials growth paradigm to produce a soft robot capable of rapid continuous growth, thereby addressing major limitations of growing soft robots that stem from limited extensibility, lack of permanent structure, and inability to negotiate torturous paths, demonstrating the potential of growth to provide new capabilities in manufacturing and soft robotics. Many natural organisms, such as fungal hyphae and plant roots, grow at their tips, enabling the generation of complex bodies composed of natural materials as well as dexterous movement and exploration. Tip growth presents an exemplary process by which materials synthesis and actuation are coupled, providing a blueprint for how growth could be realized in a synthetic system. Herein, we identify three underlying principles essential to tip-based growth of biological organisms: a fluid pressure driving force, localized polymerization for generating structure, and fluid-mediated transport of constituent materials. In this work, these evolved features inspire a synthetic materials growth process called extrusion by self-lubricated interface photopolymerization (E-SLIP), which can continuously fabricate solid profiled polymer parts with tunable mechanical properties from liquid precursors. To demonstrate the utility of E-SLIP, we create a tip-growing soft robot, outline its fundamental governing principles, and highlight its capabilities for growth at speeds up to 12 cm/min and lengths up to 1.5 m. This growing soft robot is capable of executing a range of tasks, including exploration, burrowing, and traversing tortuous paths, which highlight the potential for synthetic growth as a platform for on-demand manufacturing of infrastructure, exploration, and sensing in a variety of environments.
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9
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Yan J, Zhu J, Zhou J, Xing C, Song H, Wu K, Cai M. Using brefeldin A to disrupt cell wall polysaccharide components in rice and nitric oxide to modify cell wall structure to change aluminum tolerance. FRONTIERS IN PLANT SCIENCE 2022; 13:948212. [PMID: 35991413 PMCID: PMC9390061 DOI: 10.3389/fpls.2022.948212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
The components and structure of cell wall are closely correlated with aluminum (Al) toxicity and tolerance for plants. However, the cell wall assembly and function construction in response to Al is not known. Brefeldin A (BFA), a macrolide, is used to disrupt cell wall polysaccharide components, and nitric oxide (NO), a signal molecule, is used to modify the cell wall structure. Pretreatment with BFA accelerated Al accumulation in root tips and Al-induced inhibition of root growth of two rice genotypes of Nipponbare and Zhefu 802, and significantly decreased the cell wall polysaccharide content including pectin, hemicellulose 1, and hemicellulose 2, indicating that BFA inhibits the biosynthesis of components in the cell wall and makes the root cell wall lose the ability to resist Al. The addition of NO donor (SNP) significantly alleviated the toxic effects of Al on root growth, Al accumulation, and oxidative damage, and decreased the content of pectin polysaccharide and functional groups of hydroxyl, carboxyl, and amino in the cell wall via FTIR analysis, while had no significant effect on hemicellulose 1 and hemicellulose 2 content compared with Al treatment. Furthermore, NO didn't change the inhibition effect of BFA-induced cell wall polysaccharide biosynthesis and root growth. Taken together, BFA disrupts the integrity of cell wall and NO modifies partial cell wall composition and their functional groups, which change the Al tolerance in rice.
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Affiliation(s)
- Jianchao Yan
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Jiandong Zhu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Jun Zhou
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Chenghua Xing
- College of Agriculture, Jinhua Polytechnic, Jinhua, China
| | - Hongming Song
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Kun Wu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Miaozhen Cai
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
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10
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Lara-Mondragón CM, Dorchak A, MacAlister CA. O-glycosylation of the extracellular domain of pollen class I formins modulates their plasma membrane mobility. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3929-3945. [PMID: 35383367 PMCID: PMC9232206 DOI: 10.1093/jxb/erac131] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/31/2022] [Indexed: 06/09/2023]
Abstract
In plant cells, linkage between the cytoskeleton, plasma membrane, and cell wall is crucial for maintaining cell shape. In highly polarized pollen tubes, this coordination is especially important to allow rapid tip growth and successful fertilization. Class I formins contain cytoplasmic actin-nucleating formin homology domains as well as a proline-rich extracellular domain and are candidate coordination factors. Here, using Arabidopsis, we investigated the functional significance of the extracellular domain of two pollen-expressed class I formins: AtFH3, which does not have a polar localization, and AtFH5, which is limited to the growing tip region. We show that the extracellular domain of both is necessary for their function, and identify distinct O-glycans attached to these sequences, AtFH5 being hydroxyproline-arabinosylated and AtFH3 carrying arabinogalactan chains. Loss of hydroxyproline arabinosylation altered the plasma membrane localization of AtFH5 and disrupted actin cytoskeleton organization. Moreover, we show that O-glycans differentially affect lateral mobility in the plasma membrane. Together, our results support a model of protein sub-functionalization in which AtFH5 and AtFH3, restricted to specific plasma membrane domains by their extracellular domains and the glycans attached to them, organize distinct subarrays of actin during pollen tube elongation.
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Affiliation(s)
- Cecilia M Lara-Mondragón
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Alexandria Dorchak
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
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11
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Çetinbaş-Genç A, Conti V, Cai G. Let's shape again: the concerted molecular action that builds the pollen tube. PLANT REPRODUCTION 2022; 35:77-103. [PMID: 35041045 DOI: 10.1007/s00497-022-00437-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
The pollen tube is being subjected to control by a complex network of communication that regulates its shape and the misfunction of a single component causes specific deformations. In flowering plants, the pollen tube is a tubular extension of the pollen grain required for successful sexual reproduction. Indeed, maintaining the unique shape of the pollen tube is essential for the pollen tube to approach the embryo sac. Many processes and molecules (such as GTPase activity, phosphoinositides, Ca2+ gradient, distribution of reactive oxygen species and nitric oxide, nonuniform pH values, organization of the cytoskeleton, balance between exocytosis and endocytosis, and cell wall structure) play key and coordinated roles in maintaining the cylindrical shape of pollen tubes. In addition, the above factors must also interact with each other so that the cell shape is maintained while the pollen tube follows chemical signals in the pistil that guide it to the embryo sac. Any intrinsic changes (such as erroneous signals) or extrinsic changes (such as environmental stresses) can affect the above factors and thus fertilization by altering the tube morphology. In this review, the processes and molecules that enable the development and maintenance of the unique shape of pollen tubes in angiosperms are presented emphasizing their interaction with specific tube shape. Thus, the purpose of the review is to investigate whether specific deformations in pollen tubes can help us to better understand the mechanism underlying pollen tube shape.
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Affiliation(s)
- Aslıhan Çetinbaş-Genç
- Department of Biology, Marmara University, Göztepe Campus, 34722, Kadıköy, Istanbul, Turkey.
| | - Veronica Conti
- Department of Life Sciences, University of Siena, via Mattioli 4, 53100, Siena, Italy
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, via Mattioli 4, 53100, Siena, Italy
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12
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Wasąg P, Suwińska A, Lenartowska M, Lenartowski R. RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in Petunia. Int J Mol Sci 2022; 23:ijms23094987. [PMID: 35563382 PMCID: PMC9103332 DOI: 10.3390/ijms23094987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 04/14/2022] [Accepted: 04/26/2022] [Indexed: 02/05/2023] Open
Abstract
Pollen tube growth depends on several complex processes, including exo/endocytosis, cell wall biogenesis, intracellular transport, and cell signaling. Our previous results provided evidence that calreticulin (CRT)—a prominent calcium (Ca2+)-buffering molecular chaperone in the endoplasmic reticulum (ER) lumen—is involved in pollen tube formation and function. We previously cloned and characterized the CRT gene belonging to the CRT1/2 subgroup from Petunia hybrida (PhCRT1/2), and found that post-transcriptional silencing of PhCRT1/2 expression strongly impaired pollen tube growth in vitro. Here, we report cloning of a new PhCRT3a homolog; we identified the full-length cDNA sequence and described its molecular characteristics and phylogenetic relationships to other plant CRT3 genes. Using an RNA interference (RNAi) strategy, we found that knockdown of PhCRT3a gene expression caused numerous defects in the morphology and ultrastructure of cultivated pollen tubes, including disorganization of the actin cytoskeleton and loss of cytoplasmic zonation. Elongation of siPhCRT3a pollen tubes was disrupted, and some of them ruptured. Our present data provide the first evidence that PhCRT3a expression is required for normal pollen tube growth. Thus, we discuss relationships between diverse CRT isoforms in several interdependent processes driving the apical growth of the pollen tube, including actomyosin-dependent cytoplasmic streaming, organelle positioning, vesicle trafficking, and cell wall biogenesis.
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Affiliation(s)
- Piotr Wasąg
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland; (P.W.); (A.S.); (M.L.)
- Department of Biochemistry and Cell Biology, Faculty of Biological Sciences, Kazimierz Wielki University, 85-093 Bydgoszcz, Poland
| | - Anna Suwińska
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland; (P.W.); (A.S.); (M.L.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
| | - Marta Lenartowska
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland; (P.W.); (A.S.); (M.L.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
| | - Robert Lenartowski
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland; (P.W.); (A.S.); (M.L.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
- Correspondence:
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13
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Shi C, Wang D, Guan Y, Qu H. Dissection and ultramicroscopic observation of an apical pollen tube of Pyrus. PLANT REPRODUCTION 2022; 35:1-8. [PMID: 34731307 DOI: 10.1007/s00497-021-00433-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
The pollen tube is ideal for studying cell polar growth, and observing the ultrastructure of the pollen tube tip using transmission electron microscopy (TEM) is the primary method for studying pollen tube growth. The preparation of ultrathin sections of the pollen tube tip sample is important for its successful microscopic observation. The direction of pollen tube growth in vitro is irregular, and it is difficult to dissect the tip of the pollen tube during ultrathin sectioning. Here, we used two methods to efficiently obtain an ultrathin section of the pollen tube tip of Pyrus. In the first method, laser micro-cutting was used to obtain the pollen tube tip, followed by ultrathin sectioning. In the other method, the pollen tubes were cultured in the same growth direction, followed by ultrathin sectioning. Ultrathin sections, which were observed via TEM, showed typical characteristics of the pollen tube tip, such as dense vesicles, numerous mitochondria, and secretory vesicles of the Golgi. We concluded that these two methods are effective in pollen tube tip sample preparation for ultrathin sectioning and provide the foundation for observing the ultrastructure of pollen tube tips.
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Affiliation(s)
- Chenxi Shi
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China
| | - Demian Wang
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China
| | - Yaqin Guan
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China
| | - Haiyong Qu
- College of Horticulture, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao City, 266109, Shandong Province, China.
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14
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Scholz P, Pejchar P, Fernkorn M, Škrabálková E, Pleskot R, Blersch K, Munnik T, Potocký M, Ischebeck T. DIACYLGLYCEROL KINASE 5 regulates polar tip growth of tobacco pollen tubes. THE NEW PHYTOLOGIST 2022; 233:2185-2202. [PMID: 34931304 DOI: 10.1111/nph.17930] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Pollen tubes require a tightly regulated pectin secretion machinery to sustain the cell wall plasticity required for polar tip growth. Involved in this regulation at the apical plasma membrane are proteins and signaling molecules, including phosphoinositides and phosphatidic acid (PA). However, the contribution of diacylglycerol kinases (DGKs) is not clear. We transiently expressed tobacco DGKs in pollen tubes to identify a plasma membrane (PM)-localized isoform, and then to study its effect on pollen tube growth, pectin secretion and lipid signaling. In order to potentially downregulate DGK5 function, we overexpressed an inactive variant. Only one of eight DGKs displayed a confined localization at the apical PM. We could demonstrate its enzymatic activity and that a kinase-dead variant was inactive. Overexpression of either variant led to differential perturbations including misregulation of pectin secretion. One mode of regulation could be that DGK5-formed PA regulates phosphatidylinositol 4-phosphate 5-kinases, as overexpression of the inactive DGK5 variant not only led to a reduction of PA but also of phosphatidylinositol 4,5-bisphosphate levels and suppressed related growth phenotypes. We conclude that DGK5 is an additional player of polar tip growth that regulates pectin secretion probably in a common pathway with PI4P 5-kinases.
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Affiliation(s)
- Patricia Scholz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, 37077, Germany
| | - Přemysl Pejchar
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Max Fernkorn
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, 37077, Germany
| | - Eliška Škrabálková
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, 16502, Czech Republic
- Department of Experimental Plant Biology, Charles University, Prague, 12844, Czech Republic
| | - Roman Pleskot
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Katharina Blersch
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, 37077, Germany
- Green Biotechnology, Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Münster, 48143, Germany
| | - Teun Munnik
- Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, 1000 BE, the Netherlands
| | - Martin Potocký
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, 16502, Czech Republic
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, 37077, Germany
- Green Biotechnology, Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Münster, 48143, Germany
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15
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Bibeau JP, Galotto G, Wu M, Tüzel E, Vidali L. Quantitative cell biology of tip growth in moss. PLANT MOLECULAR BIOLOGY 2021; 107:227-244. [PMID: 33825083 PMCID: PMC8492783 DOI: 10.1007/s11103-021-01147-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/25/2021] [Indexed: 05/16/2023]
Abstract
KEY MESSAGE Here we review, from a quantitative point of view, the cell biology of protonemal tip growth in the model moss Physcomitrium patens. We focus on the role of the cytoskeleton, vesicle trafficking, and cell wall mechanics, including reviewing some of the existing mathematical models of tip growth. We provide a primer for existing cell biological tools that can be applied to the future study of tip growth in moss. Polarized cell growth is a ubiquitous process throughout the plant kingdom in which the cell elongates in a self-similar manner. This process is important for nutrient uptake by root hairs, fertilization by pollen, and gametophyte development by the protonemata of bryophytes and ferns. In this review, we will focus on the tip growth of moss cells, emphasizing the role of cytoskeletal organization, cytoplasmic zonation, vesicle trafficking, cell wall composition, and dynamics. We compare some of the existing knowledge on tip growth in protonemata against what is known in pollen tubes and root hairs, which are better-studied tip growing cells. To fully understand how plant cells grow requires that we deepen our knowledge in a variety of forms of plant cell growth. We focus this review on the model plant Physcomitrium patens, which uses tip growth as the dominant form of growth at its protonemal stage. Because mosses and vascular plants shared a common ancestor more than 450 million years ago, we anticipate that both similarities and differences between tip growing plant cells will provide mechanistic information of tip growth as well as of plant cell growth in general. Towards this mechanistic understanding, we will also review some of the existing mathematical models of plant tip growth and their applicability to investigate protonemal morphogenesis. We attempt to integrate the conclusions and data across cell biology and physical modeling to our current state of knowledge of polarized cell growth in P. patens and highlight future directions in the field.
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Affiliation(s)
- Jeffrey P Bibeau
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Giulia Galotto
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Min Wu
- Department of Mathematical Sciences, Worcester Polytechnic Institute, Worcester, MA, USA
- Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Erkan Tüzel
- Bioengineering Department, Temple University, Philadelphia, PA, USA
| | - Luis Vidali
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA.
- Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA, USA.
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16
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Gerganova V, Lamas I, Rutkowski DM, Vještica A, Castro DG, Vincenzetti V, Vavylonis D, Martin SG. Cell patterning by secretion-induced plasma membrane flows. SCIENCE ADVANCES 2021; 7:eabg6718. [PMID: 34533984 PMCID: PMC8448446 DOI: 10.1126/sciadv.abg6718] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/26/2021] [Indexed: 05/20/2023]
Abstract
Cells self-organize using reaction-diffusion and fluid-flow principles. Whether bulk membrane flows contribute to cell patterning has not been established. Here, using mathematical modeling, optogenetics, and synthetic probes, we show that polarized exocytosis causes lateral membrane flows away from regions of membrane insertion. Plasma membrane–associated proteins with sufficiently low diffusion and/or detachment rates couple to the flows and deplete from areas of exocytosis. In rod-shaped fission yeast cells, zones of Cdc42 GTPase activity driving polarized exocytosis are limited by GTPase activating proteins (GAPs). We show that membrane flows pattern the GAP Rga4 distribution and that coupling of a synthetic GAP to membrane flows is sufficient to establish the rod shape. Thus, membrane flows induced by Cdc42-dependent exocytosis form a negative feedback restricting the zone of Cdc42 activity.
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Affiliation(s)
- Veneta Gerganova
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Iker Lamas
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | | | - Aleksandar Vještica
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Daniela Gallo Castro
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Vincent Vincenzetti
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Dimitrios Vavylonis
- Department of Physics, Lehigh University, Bethlehem, PA 18015, USA
- Corresponding author. (S.G.M.); (D.V.)
| | - Sophie G. Martin
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
- Corresponding author. (S.G.M.); (D.V.)
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17
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Billey E, Hafidh S, Cruz-Gallardo I, Litholdo CG, Jean V, Carpentier MC, Picart C, Kumar V, Kulichova K, Maréchal E, Honys D, Conte MR, Deragon JM, Bousquet-Antonelli C. LARP6C orchestrates posttranscriptional reprogramming of gene expression during hydration to promote pollen tube guidance. THE PLANT CELL 2021; 33:2637-2661. [PMID: 34124761 DOI: 10.1101/2020.11.27.401307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/06/2021] [Indexed: 05/19/2023]
Abstract
Increasing evidence suggests that posttranscriptional regulation is a key player in the transition between mature pollen and the progamic phase (from pollination to fertilization). Nonetheless, the actors in this messenger RNA (mRNA)-based gene expression reprogramming are poorly understood. We demonstrate that the evolutionarily conserved RNA-binding protein LARP6C is necessary for the transition from dry pollen to pollen tubes and the guided growth of pollen tubes towards the ovule in Arabidopsis thaliana. In dry pollen, LARP6C binds to transcripts encoding proteins that function in lipid synthesis and homeostasis, vesicular trafficking, and polarized cell growth. LARP6C also forms cytoplasmic granules that contain the poly(A) binding protein and possibly represent storage sites for translationally silent mRNAs. In pollen tubes, the loss of LARP6C negatively affects the quantities and distribution of storage lipids, as well as vesicular trafficking. In Nicotiana benthamiana leaf cells and in planta, analysis of reporter mRNAs designed from the LARP6C target MGD2 provided evidence that LARP6C can shift from a repressor to an activator of translation when the pollen grain enters the progamic phase. We propose that LARP6C orchestrates the timely posttranscriptional regulation of a subset of mRNAs in pollen during the transition from the quiescent to active state and along the progamic phase to promote male fertilization in plants.
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Affiliation(s)
- Elodie Billey
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Isabel Cruz-Gallardo
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Celso G Litholdo
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Viviane Jean
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Claire Picart
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Vinod Kumar
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Katarina Kulichova
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, 38054 Grenoble, France
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Maria R Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Jean-Marc Deragon
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Institut Universitaire de France, 75231 Paris Cedex 5, France
| | - Cécile Bousquet-Antonelli
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
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18
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Billey E, Hafidh S, Cruz-Gallardo I, Litholdo CG, Jean V, Carpentier MC, Picart C, Kumar V, Kulichova K, Maréchal E, Honys D, Conte MR, Deragon JM, Bousquet-Antonelli C. LARP6C orchestrates posttranscriptional reprogramming of gene expression during hydration to promote pollen tube guidance. THE PLANT CELL 2021; 33:2637-2661. [PMID: 34124761 PMCID: PMC8408461 DOI: 10.1093/plcell/koab131] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/06/2021] [Indexed: 05/15/2023]
Abstract
Increasing evidence suggests that posttranscriptional regulation is a key player in the transition between mature pollen and the progamic phase (from pollination to fertilization). Nonetheless, the actors in this messenger RNA (mRNA)-based gene expression reprogramming are poorly understood. We demonstrate that the evolutionarily conserved RNA-binding protein LARP6C is necessary for the transition from dry pollen to pollen tubes and the guided growth of pollen tubes towards the ovule in Arabidopsis thaliana. In dry pollen, LARP6C binds to transcripts encoding proteins that function in lipid synthesis and homeostasis, vesicular trafficking, and polarized cell growth. LARP6C also forms cytoplasmic granules that contain the poly(A) binding protein and possibly represent storage sites for translationally silent mRNAs. In pollen tubes, the loss of LARP6C negatively affects the quantities and distribution of storage lipids, as well as vesicular trafficking. In Nicotiana benthamiana leaf cells and in planta, analysis of reporter mRNAs designed from the LARP6C target MGD2 provided evidence that LARP6C can shift from a repressor to an activator of translation when the pollen grain enters the progamic phase. We propose that LARP6C orchestrates the timely posttranscriptional regulation of a subset of mRNAs in pollen during the transition from the quiescent to active state and along the progamic phase to promote male fertilization in plants.
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Affiliation(s)
- Elodie Billey
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Isabel Cruz-Gallardo
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Celso G. Litholdo
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Viviane Jean
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Claire Picart
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Vinod Kumar
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Katarina Kulichova
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, 38054 Grenoble, France
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague 6, Czech Republic
| | - Maria R. Conte
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Jean-Marc Deragon
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Institut Universitaire de France, 75231 Paris Cedex 5, France
| | - Cécile Bousquet-Antonelli
- Laboratoire Génome et Développement des Plantes, UMR5096, CNRS, 66860 Perpignan, France
- Laboratoire Génome et Développement des Plantes, UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
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19
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Abstract
Pollen-pistil interactions serve as important prezygotic reproductive barriers that play a critical role in mate selection in plants. Here, we highlight recent progress toward understanding the molecular basis of pollen-pistil interactions as reproductive isolating barriers. These barriers can be active systems of pollen rejection, or they can result from a mismatch of required male and female factors. In some cases, the barriers are mechanistically linked to self-incompatibility systems, while others represent completely independent processes. Pollen-pistil reproductive barriers can act as soon as pollen is deposited on a stigma, where penetration of heterospecific pollen tubes is blocked by the stigma papillae. As pollen tubes extend, the female transmitting tissue can selectively limit growth by producing cell wall-modifying enzymes and cytotoxins that interact with the growing pollen tube. At ovules, differential pollen tube attraction and inhibition of sperm cell release can act as barriers to heterospecific pollen tubes.
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Affiliation(s)
- Amanda K Broz
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523-1878, USA; ,
| | - Patricia A Bedinger
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523-1878, USA; ,
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20
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Fratini M, Krishnamoorthy P, Stenzel I, Riechmann M, Matzner M, Bacia K, Heilmann M, Heilmann I. Plasma membrane nano-organization specifies phosphoinositide effects on Rho-GTPases and actin dynamics in tobacco pollen tubes. THE PLANT CELL 2021; 33:642-670. [PMID: 33955493 PMCID: PMC8136918 DOI: 10.1093/plcell/koaa035] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/23/2020] [Indexed: 05/04/2023]
Abstract
Pollen tube growth requires coordination of cytoskeletal dynamics and apical secretion. The regulatory phospholipid phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) is enriched in the subapical plasma membrane of pollen tubes of Arabidopsis thaliana and tobacco (Nicotiana tabacum) and can influence both actin dynamics and secretion. How alternative PtdIns(4,5)P2 effects are specified is unclear. In tobacco pollen tubes, spinning disc microscopy (SD) reveals dual distribution of a fluorescent PtdIns(4,5)P2-reporter in dynamic plasma membrane nanodomains vs. apparent diffuse membrane labeling, consistent with spatially distinct coexisting pools of PtdIns(4,5)P2. Several PI4P 5-kinases (PIP5Ks) can generate PtdIns(4,5)P2 in pollen tubes. Despite localizing to one membrane region, the PIP5Ks AtPIP5K2-EYFP and NtPIP5K6-EYFP display distinctive overexpression effects on cell morphologies, respectively related to altered actin dynamics or membrane trafficking. When analyzed by SD, AtPIP5K2-EYFP associated with nanodomains, whereas NtPIP5K6-EYFP localized diffusely. Chimeric AtPIP5K2-EYFP and NtPIP5K6-EYFP variants with reciprocally swapped membrane-associating domains evoked reciprocally shifted effects on cell morphology upon overexpression. Overall, active PI4P 5-kinase variants stabilized actin when targeted to nanodomains, suggesting a role of nanodomain-associated PtdIns(4,5)P2 in actin regulation. This notion is further supported by interaction and proximity of nanodomain-associated AtPIP5K2 with the Rho-GTPase NtRac5, and by its functional interplay with elements of Rho of plants signaling. Plasma membrane nano-organization may thus aid the specification of PtdIns(4,5)P2 functions to coordinate cytoskeletal dynamics and secretion.
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Affiliation(s)
- Marta Fratini
- Department of Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Praveen Krishnamoorthy
- Department of Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Irene Stenzel
- Department of Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Mara Riechmann
- Department of Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Monique Matzner
- Department of Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Kirsten Bacia
- Department of Biophysical Chemistry, Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Mareike Heilmann
- Department of Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Ingo Heilmann
- Department of Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
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21
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Duan X, Chen X, Wang K, Chen L, Glomb O, Johnsson N, Feng L, Zhou XQ, Bi E. Essential role of the endocytic site-associated protein Ecm25 in stress-induced cell elongation. Cell Rep 2021; 35:109122. [PMID: 34010635 PMCID: PMC8202958 DOI: 10.1016/j.celrep.2021.109122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 02/16/2021] [Accepted: 04/22/2021] [Indexed: 11/27/2022] Open
Abstract
How cells adopt a different morphology to cope with stress is not well understood. Here, we show that budding yeast Ecm25 associates with polarized endocytic sites and interacts with the polarity regulator Cdc42 and several late-stage endocytic proteins via distinct regions, including an actin filament-binding motif. Deletion of ECM25 does not affect Cdc42 activity or cause any strong defects in fluid-phase and clathrin-mediated endocytosis but completely abolishes hydroxyurea-induced cell elongation. This phenotype is accompanied by depolarization of the spatiotemporally coupled exo-endocytosis in the bud cortex while maintaining the overall mother-bud polarity. These data suggest that Ecm25 provides an essential link between the polarization signal and the endocytic machinery to enable adaptive morphogenesis under stress conditions. How cells adopt a different morphology to cope with stress is not well understood. Duan et al. report that the budding yeast protein Ecm25 plays an essential role in stress-induced cell elongation by linking the polarity regulator Cdc42 to the late-stage endocytic machinery.
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Affiliation(s)
- Xudong Duan
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA; Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130 Sichuan, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Xi Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Kangji Wang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Li Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Oliver Glomb
- Institut für Molekulare Genetik und Zellbiologie, Universität Ulm, 89081 Ulm, Germany
| | - Nils Johnsson
- Institut für Molekulare Genetik und Zellbiologie, Universität Ulm, 89081 Ulm, Germany
| | - Lin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130 Sichuan, China
| | - Xiao-Qiu Zhou
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130 Sichuan, China.
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA.
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22
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Overdijk EJR, Putker V, Smits J, Tang H, Bouwmeester K, Govers F, Ketelaar T. Phytophthora infestans RXLR effector AVR1 disturbs the growth of Physcomitrium patens without affecting Sec5 localization. PLoS One 2021; 16:e0249637. [PMID: 33831039 PMCID: PMC8031463 DOI: 10.1371/journal.pone.0249637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 03/22/2021] [Indexed: 11/19/2022] Open
Abstract
Plant pathogens often exploit a whole range of effectors to facilitate infection. The RXLR effector AVR1 produced by the oomycete plant pathogen Phytophthora infestans suppresses host defense by targeting Sec5. Sec5 is a subunit of the exocyst, a protein complex that is important for mediating polarized exocytosis during plant development and defense against pathogens. The mechanism by which AVR1 manipulates Sec5 functioning is unknown. In this study, we analyzed the effect of AVR1 on Sec5 localization and functioning in the moss Physcomitrium patens. P. patens has four Sec5 homologs. Two (PpSec5b and PpSec5d) were found to interact with AVR1 in yeast-two-hybrid assays while none of the four showed a positive interaction with AVR1ΔT, a truncated version of AVR1. In P. patens lines carrying β-estradiol inducible AVR1 or AVR1ΔT transgenes, expression of AVR1 or AVR1ΔT caused defects in the development of caulonemal protonema cells and abnormal morphology of chloronema cells. Similar phenotypes were observed in Sec5- or Sec6-silenced P. patens lines, suggesting that both AVR1 and AVR1ΔT affect exocyst functioning in P. patens. With respect to Sec5 localization we found no differences between β-estradiol-treated and untreated transgenic AVR1 lines. Sec5 localizes at the plasma membrane in growing caulonema cells, also during pathogen attack, and its subcellular localization is the same, with or without AVR1 in the vicinity.
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Affiliation(s)
- Elysa J. R. Overdijk
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, The Netherlands
| | - Vera Putker
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
| | - Joep Smits
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
| | - Han Tang
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
| | - Klaas Bouwmeester
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, The Netherlands
- Biosystematics Group, Wageningen University & Research, Wageningen, The Netherlands
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, The Netherlands
- * E-mail:
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
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23
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Liu Z, Gao J, Cui Y, Klumpe S, Xiang Y, Erdmann PS, Jiang L. Membrane imaging in the plant endomembrane system. PLANT PHYSIOLOGY 2021; 185:562-576. [PMID: 33793889 PMCID: PMC8133680 DOI: 10.1093/plphys/kiaa040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/11/2020] [Indexed: 05/10/2023]
Abstract
Recent studies on membrane imaging in the plant endomembrane system by 2-D/3-D CLSM and TEM provide future perspectives of whole-cell ET and cryo-FIB-aided cryo-ET analysis.
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Affiliation(s)
- Zhiqi Liu
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Jiayang Gao
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yong Cui
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Sven Klumpe
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Philipp S Erdmann
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
- Author for communication: (L.J.)
| | - Liwen Jiang
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China
- Author for communication: (L.J.)
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Scali M, Moscatelli A, Bini L, Onelli E, Vignani R, Wang W. Protein Analysis of Pollen Tubes after the Treatments of Membrane Trafficking Inhibitors Gains Insights on Molecular Mechanism Underlying Pollen Tube Polar Growth. Protein J 2021; 40:205-222. [PMID: 33751342 PMCID: PMC8019430 DOI: 10.1007/s10930-021-09972-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2021] [Indexed: 12/03/2022]
Abstract
Pollen tube elongation is characterized by a highly-polarized tip growth process dependent on an efficient vesicular transport system and largely mobilized by actin cytoskeleton. Pollen tubes are an ideal model system to study exocytosis, endocytosis, membrane recycling, and signaling network coordinating cellular processes, structural organization and vesicular trafficking activities required for tip growth. Proteomic analysis was applied to identify Nicotiana tabacum Differentially Abundant Proteins (DAPs) after in vitro pollen tube treatment with membrane trafficking inhibitors Brefeldin A, Ikarugamycin and Wortmannin. Among roughly 360 proteins separated in two-dimensional gel electrophoresis, a total of 40 spots visibly changing between treated and control samples were identified by MALDI-TOF MS and LC-ESI-MS/MS analysis. The identified proteins were classified according to biological processes, and most proteins were related to pollen tube energy metabolism, including ammino acid synthesis and lipid metabolism, structural features of pollen tube growth as well modification and actin cytoskeleton organization, stress response, and protein degradation. In-depth analysis of proteins corresponding to energy-related pathways revealed the male gametophyte to be a reliable model of energy reservoir and dynamics.
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Affiliation(s)
- Monica Scali
- Department of Life Sciences, University of Siena, Siena, Italy.
| | | | - Luca Bini
- Department of Life Sciences, University of Siena, Siena, Italy
| | | | - Rita Vignani
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Wei Wang
- College of Life Sciences, Henan Agricultural University, Zhengzhou, China
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25
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Okada H, MacTaggart B, Ohya Y, Bi E. The kinetic landscape and interplay of protein networks in cytokinesis. iScience 2021; 24:101917. [PMID: 33392480 PMCID: PMC7773586 DOI: 10.1016/j.isci.2020.101917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/08/2022] Open
Abstract
Cytokinesis is executed by protein networks organized into functional modules. Individual proteins within each module have been characterized to various degrees. However, the collective behavior and interplay of the modules remain poorly understood. In this study, we conducted quantitative time-lapse imaging to analyze the accumulation kinetics of more than 20 proteins from different modules of cytokinesis in budding yeast. This analysis has led to a comprehensive picture of the kinetic landscape of cytokinesis, from actomyosin ring (AMR) assembly to cell separation. It revealed that the AMR undergoes biphasic constriction and that the switch between the constriction phases is likely triggered by AMR maturation and primary septum formation. This analysis also provided further insights into the functions of actin filaments and the transglutaminase-like protein Cyk3 in cytokinesis and, in addition, defined Kre6 as the likely enzyme that catalyzes β-1,6-glucan synthesis to drive cell wall maturation during cell growth and division. Cytokinesis is executed by protein modules each with a unique kinetic signature Actomyosin ring constricts in a biphasic manner that is elaborately regulated The transglutaminase-like domain in Cyk3 plays a dual role in cytokinesis Kre6 catalyzes β-1,6-glucan synthesis at the cell surface during growth and division
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Affiliation(s)
- Hiroki Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Brittany MacTaggart
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Yoshikazu Ohya
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
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26
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Kollárová E, Baquero Forero A, Cvrčková F. The Arabidopsis thaliana Class II Formin FH13 Modulates Pollen Tube Growth. FRONTIERS IN PLANT SCIENCE 2021; 12:599961. [PMID: 33679824 PMCID: PMC7929981 DOI: 10.3389/fpls.2021.599961] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 01/29/2021] [Indexed: 05/10/2023]
Abstract
Formins are a large, evolutionarily conserved family of actin-nucleating proteins with additional roles in regulating microfilament, microtubule, and membrane dynamics. Angiosperm formins, expressed in both sporophytic and gametophytic tissues, can be divided into two subfamilies, Class I and Class II, each often exhibiting characteristic domain organization. Gametophytically expressed Class I formins have been documented to mediate plasma membrane-based actin assembly in pollen grains and pollen tubes, contributing to proper pollen germination and pollen tube tip growth, and a rice Class II formin, FH5/RMD, has been proposed to act as a positive regulator of pollen tube growth based on mutant phenotype and overexpression data. Here we report functional characterization of the Arabidopsis thaliana pollen-expressed typical Class II formin FH13 (At5g58160). Consistent with published transcriptome data, live-cell imaging in transgenic plants expressing fluorescent protein-tagged FH13 under the control of the FH13 promoter revealed expression in pollen and pollen tubes with non-homogeneous signal distribution in pollen tube cytoplasm, suggesting that this formin functions in the male gametophyte. Surprisingly, fh13 loss of function mutations do not affect plant fertility but result in stimulation of in vitro pollen tube growth, while tagged FH13 overexpression inhibits pollen tube elongation. Pollen tubes of mutants expressing a fluorescent actin marker exhibited possible minor alterations of actin organization. Our results thus indicate that FH13 controls or limits pollen tube growth, or, more generally, that typical Class II formins should be understood as modulators of pollen tube elongation rather than merely components of the molecular apparatus executing tip growth.
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Liu HK, Li YJ, Wang SJ, Yuan TL, Huang WJ, Dong X, Pei JQ, Zhang D, McCormick S, Tang WH. Kinase Partner Protein Plays a Key Role in Controlling the Speed and Shape of Pollen Tube Growth in Tomato. PLANT PHYSIOLOGY 2020; 184:1853-1869. [PMID: 33020251 PMCID: PMC7723124 DOI: 10.1104/pp.20.01081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 09/23/2020] [Indexed: 05/10/2023]
Abstract
The rapid and responsive growth of a pollen tube requires delicate coordination of membrane receptor signaling, Rho-of-Plants (ROP) GTPase activity switching, and actin cytoskeleton assembly. The tomato (Solanum lycopersicum) kinase partner protein (KPP), is a ROP guanine nucleotide exchange factor (GEF) that activates ROP GTPases and interacts with the tomato pollen receptor kinases LePRK1 and LePRK2. It remains unclear how KPP relays signals from plasma membrane-localized LePRKs to ROP switches and other cellular machineries to modulate pollen tube growth. Here, we biochemically verified KPP's activity on ROP4 and showed that KPP RNA interference transgenic pollen tubes grew slower while KPP-overexpressing pollen tubes grew faster, suggesting that KPP functions as a rheostat for speed control in LePRK2-mediated pollen tube growth. The N terminus of KPP is required for self-inhibition of its ROPGEF activity, and expression of truncated KPP lacking the N terminus caused pollen tube tip enlargement. The C-terminus of KPP is required for its interaction with LePRK1 and LePRK2, and the expression of a truncated KPP lacking the C-terminus triggered pollen tube bifurcation. Furthermore, coexpression assays showed that self-associated KPP recruited actin-nucleating Actin-Related Protein2/3 (ARP2/3) complexes to the tip membrane. Interfering with ARP2/3 activity reduced the pollen tube abnormalities caused by overexpressing KPP fragments. In conclusion, KPP plays a key role in pollen tube speed and shape control by recruiting the branched actin nucleator ARP2/3 complex and an actin bundler to the membrane-localized receptors LePRK1 and LePRK2.
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Affiliation(s)
- Hai-Kuan Liu
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu-Jie Li
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shu-Jie Wang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ting-Lu Yuan
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Jie Huang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Dong
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jia-Qi Pei
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Sheila McCormick
- Plant Gene Expression Center, United States Department of Agriculture/Agricultural Research Service, and Department of Plant and Microbial Biology, University of California at Berkeley, Albany, California 94710
| | - Wei-Hua Tang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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Adhikari PB, Liu X, Kasahara RD. Mechanics of Pollen Tube Elongation: A Perspective. FRONTIERS IN PLANT SCIENCE 2020; 11:589712. [PMID: 33193543 PMCID: PMC7606272 DOI: 10.3389/fpls.2020.589712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/30/2020] [Indexed: 05/13/2023]
Abstract
Pollen tube (PT) serves as a vehicle that delivers male gametes (sperm cells) to a female gametophyte during double fertilization, which eventually leads to the seed formation. It is one of the fastest elongating structures in plants. Normally, PTs traverse through the extracellular matrix at the transmitting tract after penetrating the stigma. While the endeavor may appear simple, the molecular processes and mechanics of the PT elongation is yet to be fully resolved. Although it is the most studied "tip-growing" structure in plants, several features of the structure (e.g., Membrane dynamics, growth behavior, mechanosensing etc.) are only partially understood. In many aspects, PTs are still considered as a tissue rather than a "unique cell." In this review, we have attempted to discuss mainly on the mechanics behind PT-elongation and briefly on the molecular players involved in the process. Four aspects of PTs are particularly discussed: the PT as a cell, its membrane dynamics, mechanics of its elongation, and the potential mechanosensors involved in its elongation based on relevant findings in both plant and non-plant models.
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Affiliation(s)
- Prakash Babu Adhikari
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Horticultural Plant Biology and Metabolomics Center (HBMC), Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaoyan Liu
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Horticultural Plant Biology and Metabolomics Center (HBMC), Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ryushiro D. Kasahara
- School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Horticultural Plant Biology and Metabolomics Center (HBMC), Fujian Agriculture and Forestry University, Fuzhou, China
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29
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Longin R-SNARE is retrieved from the plasma membrane by ANTH domain-containing proteins in Arabidopsis. Proc Natl Acad Sci U S A 2020; 117:25150-25158. [PMID: 32968023 PMCID: PMC7547277 DOI: 10.1073/pnas.2011152117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The plasma membrane (PM) acts as the interface between intra- and extracellular environments and is thus important for intercellular communication and extracellular signal perception. The composition and amounts of PM proteins are tightly regulated, by molecular mechanisms that remain largely unknown in plant cells. We identified a pair of ANTH domain-containing proteins functioning as adaptors for the retrieval of VAMP72 members, which are components of the membrane fusion machinery, during clathrin-mediated endocytosis. Our results further indicate that the recycling mechanisms of homologous VAMP7 proteins are different in plants and animals, suggesting a divergence of the endocytosis mechanism between these two kingdoms. The plasma membrane (PM) acts as the interface between intra- and extracellular environments and exhibits a tightly regulated molecular composition. The composition and amount of PM proteins are regulated by balancing endocytic and exocytic trafficking in a cargo-specific manner, according to the demands of specific cellular states and developmental processes. In plant cells, retrieval of membrane proteins from the PM depends largely on clathrin-mediated endocytosis (CME). However, the mechanisms for sorting PM proteins during CME remain ambiguous. In this study, we identified a homologous pair of ANTH domain-containing proteins, PICALM1a and PICALM1b, as adaptor proteins for CME of the secretory vesicle-associated longin-type R-SNARE VAMP72 group. PICALM1 interacted with the SNARE domain of VAMP72 and clathrin at the PM. The loss of function of PICALM1 resulted in faulty retrieval of VAMP72, whereas general endocytosis was not considerably affected by this mutation. The double mutant of PICALM1 exhibited impaired vegetative development, indicating the requirement of VAMP72 recycling for normal plant growth. In the mammalian system, VAMP7, which is homologous to plant VAMP72, is retrieved from the PM via the interaction with a clathrin adaptor HIV Rev-binding protein in the longin domain during CME, which is not functional in the plant system, whereas retrieval of brevin-type R-SNARE members is dependent on a PICALM1 homolog. These results indicate that ANTH domain-containing proteins have evolved to be recruited distinctly for recycling R-SNARE proteins and are critical to eukaryote physiology.
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30
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Zhou Y, Yang Y, Niu Y, Fan T, Qian D, Luo C, Shi Y, Li S, An L, Xiang Y. The Tip-Localized Phosphatidylserine Established by Arabidopsis ALA3 Is Crucial for Rab GTPase-Mediated Vesicle Trafficking and Pollen Tube Growth. THE PLANT CELL 2020; 32:3170-3187. [PMID: 32817253 PMCID: PMC7534478 DOI: 10.1105/tpc.19.00844] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 07/17/2020] [Accepted: 08/17/2020] [Indexed: 05/20/2023]
Abstract
RabA4 subfamily proteins, the key regulators of intracellular transport, are vital for tip growth of plant polar cells, but their unique distribution in the apical zone and role in vesicle targeting and trafficking in the tips remain poorly understood. Here, we found that loss of Arabidopsis (Arabidopsis thaliana) AMINOPHOSPHOLIPID ATPASE 3 (ALA3) function resulted in a marked decrease in YFP-RabA4b/ RFP-RabA4d- and FM4-64-labeled vesicles from the inverted-cone zone of the pollen tube tip, misdistribution of certain intramembrane compartment markers, and an obvious increase in pollen tube width. Additionally, we revealed that phosphatidylserine (PS) was abundant in the inverted-cone zone of the apical pollen tube in wild-type Arabidopsis and was mainly colocalized with the trans-Golgi network/early endosome, certain post-Golgi compartments, and the plasma membrane. Loss of ALA3 function resulted in loss of polar localization of apical PS and significantly decreased PS distribution, suggesting that ALA3 is a key regulator for establishing and maintaining the polar localization of apical PS in pollen tubes. We further demonstrated that certain Rab GTPases colocalized with PS in vivo and bound to PS in vitro. Moreover, ALA3 and RabA4d collectively regulated pollen tube growth genetically. Thus, we propose that the tip-localized PS established by ALA3 is crucial for Rab GTPase-mediated vesicle targeting/trafficking and polar growth of pollen tubes in Arabidopsis.
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Affiliation(s)
- Yuelong Zhou
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yang Yang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yue Niu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - TingTing Fan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Dong Qian
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Changxin Luo
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yumei Shi
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Shanwei Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Lizhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
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31
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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: 11] [Impact Index Per Article: 2.8] [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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32
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Grebnev G, Cvitkovic M, Fritz C, Cai G, Smith AS, Kost B. Quantitative Structural Organization of Bulk Apical Membrane Traffic in Pollen Tubes. PLANT PHYSIOLOGY 2020; 183:1559-1585. [PMID: 32482906 PMCID: PMC7401101 DOI: 10.1104/pp.20.00380] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/15/2020] [Indexed: 05/13/2023]
Abstract
Pollen tube tip growth depends on balancing secretion of cell wall material with endocytic recycling of excess material incorporated into the plasma membrane (PM). The classical model of tip growth, which predicts bulk secretion, occurs apically, and is compensated by subapical endocytosis, has been challenged in recent years. Many signaling proteins and lipids with important functions in the regulation of membrane traffic underlying tip growth associate with distinct regions of the pollen tube PM, and understanding the mechanisms responsible for the targeting of these regulatory factors to specific PM domains requires quantitative information concerning the sites of bulk secretion and endocytosis. Here, we quantitatively characterized the spatial organization of membrane traffic during tip growth by analyzing steady-state distributions and dynamics of FM4-64-labeled lipids and YFP-tagged transmembrane (TM) proteins in tobacco (Nicotiana tabacum) pollen tubes growing normally or treated with Brefeldin A to block secretion. We established that (1) secretion delivers TM proteins and recycled membrane lipids to the same apical PM domain, and (2) FM4-64-labeled lipids, but not the analyzed TM proteins, undergo endocytic recycling within a clearly defined subapical region. We mathematically modeled the steady-state PM distributions of all analyzed markers to better understand differences between them and to support the experimental data. Finally, we mapped subapical F-actin fringe and trans-Golgi network positioning relative to sites of bulk secretion and endocytosis to further characterize functions of these structures in apical membrane traffic. Our results support and further define the classical model of apical membrane traffic at the tip of elongating pollen tubes.
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Affiliation(s)
- Gleb Grebnev
- Cell Biology, Department of Biology, Friedrich-Alexander-University Erlangen Nuremberg, 91058 Erlangen, Germany
| | - Mislav Cvitkovic
- PULS Group, Department of Physics, Friedrich-Alexander-University Erlangen Nuremberg, 91058 Erlangen, Germany
- Group for Computational Life Sciences, Division of Physical Chemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Carolin Fritz
- Cell Biology, Department of Biology, Friedrich-Alexander-University Erlangen Nuremberg, 91058 Erlangen, Germany
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Ana-Suncana Smith
- PULS Group, Department of Physics, Friedrich-Alexander-University Erlangen Nuremberg, 91058 Erlangen, Germany
- Group for Computational Life Sciences, Division of Physical Chemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Benedikt Kost
- Cell Biology, Department of Biology, Friedrich-Alexander-University Erlangen Nuremberg, 91058 Erlangen, Germany
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33
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Kim YJ, Jeong HY, Kang SY, Silva J, Kim EJ, Park SK, Jung KH, Lee C. Physiological Importance of Pectin Modifying Genes During Rice Pollen Development. Int J Mol Sci 2020; 21:E4840. [PMID: 32650624 PMCID: PMC7402328 DOI: 10.3390/ijms21144840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 06/30/2020] [Accepted: 07/07/2020] [Indexed: 01/02/2023] Open
Abstract
Although cell wall dynamics, particularly modification of homogalacturonan (HGA, a major component of pectin) during pollen tube growth, have been extensively studied in dicot plants, little is known about how modification of the pollen tube cell wall regulates growth in monocot plants. In this study, we assessed the role of HGA modification during elongation of the rice pollen tube by adding a pectin methylesterase (PME) enzyme or a PME-inhibiting catechin extract (Polyphenon 60) to in vitro germination medium. Both treatments led to a severe decrease in the pollen germination rate and elongation. Furthermore, using monoclonal antibodies toward methyl-esterified and de-esterified HGA epitopes, it was found that exogenous treatment of PME and Polyphenon 60 resulted in the disruption of the distribution patterns of low- and high-methylesterified pectins upon pollen germination and during pollen tube elongation. Eleven PMEs and 13 PME inhibitors (PMEIs) were identified by publicly available transcriptome datasets and their specific expression was validated by qRT-PCR. Enzyme activity assays and subcellular localization using a heterologous expression system in tobacco leaves demonstrated that some of the pollen-specific PMEs and PMEIs possessed distinct enzymatic activities and targeted either the cell wall or other compartments. Taken together, our findings are the first line of evidence showing the essentiality of HGA methyl-esterification status during the germination and elongation of pollen tubes in rice, which is primarily governed by the fine-tuning of PME and PMEI activities.
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Affiliation(s)
- Yu-Jin Kim
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea; (Y.-J.K.); (S.-Y.K.); (J.S.); (E.-J.K.)
| | - Ho Young Jeong
- Department of Plant & Environmental New Resources, College of Life Sciences, Kyung Hee University, Yongin 17104, Korea;
| | - Seung-Yeon Kang
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea; (Y.-J.K.); (S.-Y.K.); (J.S.); (E.-J.K.)
| | - Jeniffer Silva
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea; (Y.-J.K.); (S.-Y.K.); (J.S.); (E.-J.K.)
| | - Eui-Jung Kim
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea; (Y.-J.K.); (S.-Y.K.); (J.S.); (E.-J.K.)
| | - Soon Ki Park
- School of Applied Biosciences, Kyungpook National University, Daegu 41566, Korea;
| | - Ki-Hong Jung
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea; (Y.-J.K.); (S.-Y.K.); (J.S.); (E.-J.K.)
| | - Chanhui Lee
- Department of Plant & Environmental New Resources, College of Life Sciences, Kyung Hee University, Yongin 17104, Korea;
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34
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Pejchar P, Sekereš J, Novotný O, Žárský V, Potocký M. Functional analysis of phospholipase Dδ family in tobacco pollen tubes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:212-226. [PMID: 32064689 DOI: 10.1111/tpj.14720] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/17/2020] [Accepted: 02/04/2020] [Indexed: 06/10/2023]
Abstract
Phosphatidic acid (PA), an important signalling and metabolic phospholipid, is predominantly localized in the subapical plasma membrane (PM) of growing pollen tubes. PA can be produced from structural phospholipids by phospholipase D (PLD), but the isoforms responsible for production of PM PA were not identified yet and their functional roles remain unknown. Following genome-wide bioinformatic analysis of the PLD family in tobacco, we focused on the pollen-overrepresented PLDδ class. Combining live-cell imaging, gene overexpression, lipid-binding and structural bioinformatics, we characterized five NtPLDδ isoforms. Distinct PLDδ isoforms preferentially localize to the cytoplasm or subapical PM. Using fluorescence recovery after photobleaching, domain deletion and swapping analyses we show that membrane-bound PLDδs are tightly bound to PM, primarily via the central catalytic domain. Overexpression analyses suggested isoform PLDδ3 as the most important member of the PLDδ subfamily active in pollen tubes. Moreover, only PLDδ3 shows significant constitutive PLD activity in vivo and, in turn, PA promotes binding of PLDδ3 to the PM. This forms a positive feedback loop leading to PA accumulation and the formation of massive PM invaginations. Tightly controlled production of PA generated by PLDδ3 at the PM is important for maintaining the balance between various membrane trafficking processes that are crucial for plant cell tip growth.
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Affiliation(s)
- Přemysl Pejchar
- Institute of Experimental Botany of the Czech Academy of Sciences, 16502, Prague 6, Czech Republic
| | - Juraj Sekereš
- Institute of Experimental Botany of the Czech Academy of Sciences, 16502, Prague 6, Czech Republic
| | - Ondřej Novotný
- Institute of Experimental Botany of the Czech Academy of Sciences, 16502, Prague 6, Czech Republic
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, 16628, Prague 6, Czech Republic
| | - Viktor Žárský
- Institute of Experimental Botany of the Czech Academy of Sciences, 16502, Prague 6, Czech Republic
- Department of Experimental Plant Biology, Charles University, 128 44, Prague 2, Czech Republic
| | - Martin Potocký
- Institute of Experimental Botany of the Czech Academy of Sciences, 16502, Prague 6, Czech Republic
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35
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Testing Pollen Tube Proteins for In Vivo Binding to Phosphatidic Acid by n-Butanol Treatment and Confocal Microscopy. Methods Mol Biol 2020. [PMID: 32529446 DOI: 10.1007/978-1-0716-0672-8_22] [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 general role of cellular membranes is to provide a barrier and to generate separate reaction spaces. However, additional functions of membrane domains enriched in certain classes of lipids have been discovered, which represent an important area of ongoing research. Such membrane domains can be found in cells at different size scales (e.g., nanodomains, microdomains), represent membrane regions with special physical properties and play important roles in the direct or indirect propagation of signaling processes. Domain formation within the plasma membrane (PM) does not only involve the accumulation of specific lipids, but also the recruitment of specific transmembrane or PM-associated peripheral proteins. Phosphatidic acid (PA) is increasingly recognized as an important signaling lipid and component of PM domains. This lipid is involved in the regulation not only of biotic or abiotic stress responses, but also of pollen tube tip growth and of other forms of polar cell expansion. Although many PA-binding proteins have been characterized, a conserved PA interaction motif could not be identified in these proteins. Consequently, protein binding to PA cannot be predicted based on sequence analysis, but has to be biochemically tested using lipid strip or liposome assays. Although these assays are often informative, they are generally based on the use of artificial model membranes, which compared to natural membranes contain fewer lipid types often at non-physiological concentrations. In this chapter, we describe an alternative in vivo assay that can be employed to analyze protein binding to PA at the PM of normally elongating tobacco pollen tubes. This assay is based on the use of n-butanol (n-ButOH), which inhibits phospholipase D (PLD) and thereby blocks a major biosynthetic pathway that generates PA within the PM from substrates like phosphatidylcholine (PC) or phosphatidylethanolamine (PE). PLD inhibition reduces the PA content of the PM and consequently the level of PM association of PA-binding proteins, which can be analyzed using fluorescence microscopy. Methods enabling n-ButOH treatment of cultured tobacco pollen tubes expressing YFP-tagged PA-binding proteins as well as the quantitative determination of the PM association of these proteins are described.
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36
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Domozych DS, Sun L, Palacio-Lopez K, Reed R, Jeon S, Li M, Jiao C, Sørensen I, Fei Z, Rose JKC. Endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte, Penium margaritaceum. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3323-3339. [PMID: 31974570 PMCID: PMC7289721 DOI: 10.1093/jxb/eraa039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/21/2020] [Indexed: 05/02/2023]
Abstract
The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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Affiliation(s)
- David S Domozych
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
- Correspondence:
| | - Li Sun
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | | | - Reagan Reed
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Susan Jeon
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Mingjia Li
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Chen Jiao
- Boyce Thompson Institute, Ithaca, NY, USA
| | - Iben Sørensen
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Zhangjun Fei
- Boyce Thompson Institute, Ithaca, NY, USA
- U.S. Department of Agriculture-Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY, USA
| | - Jocelyn K C Rose
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
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Larson ER. Pollen Tubes Use Matrix Rigidity to Direct Growth. PLANT PHYSIOLOGY 2020; 183:423-424. [PMID: 32493800 PMCID: PMC7271801 DOI: 10.1104/pp.20.00481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Emily R Larson
- School of Biological Science, University of Bristol, Bristol, BS8 1TQ United Kingdom
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38
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Reimann R, Kah D, Mark C, Dettmer J, Reimann TM, Gerum RC, Geitmann A, Fabry B, Dietrich P, Kost B. Durotropic Growth of Pollen Tubes. PLANT PHYSIOLOGY 2020; 183:558-569. [PMID: 32241878 PMCID: PMC7271775 DOI: 10.1104/pp.19.01505] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/23/2020] [Indexed: 05/06/2023]
Abstract
To reach the female gametophyte, growing pollen tubes must penetrate different tissues within the pistil, the female reproductive organ of a flower. Past research has identified various chemotropic cues that guide pollen tubes through the transmitting tract of the pistil, which represents the longest segment of its growth path. In addition, physical mechanisms also play a role in pollen tube guidance; however, these processes remain poorly understood. Here we show that pollen tubes from plants with solid transmitting tracts actively respond to the stiffness of the environment. We found that pollen tubes from Nicotiana tabacum and other plant species with a solid or semisolid transmitting tract increase their growth rate in response to an increasing matrix stiffness. By contrast, pollen tubes from Lilium longiflorum and other plant species with a hollow transmitting tract decrease their growth rate with increasing matrix stiffness, even though the forces needed to maintain a constant growth rate remain far below the maximum penetration force these pollen tubes are able to generate. Moreover, when confronted with a transition from a softer to a stiffer matrix, pollen tubes from N. tabacum display a greater ability to penetrate into a stiffer matrix compared with pollen tubes from L. longiflorum, even though the maximum force generated by pollen tubes from N. tabacum (11 µN) is smaller than the maximum force generated by pollen tubes from L. longiflorum (36 µN). These findings demonstrate a mechano-sensitive growth behavior, termed here durotropic growth, that is only expressed in pollen tubes from plants with a solid or semisolid transmitting tract and thus may contribute to an effective pollen tube guidance within the pistil.
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Affiliation(s)
- Ronny Reimann
- Cell Biology, Department of Biology, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
- Molecular Plant Physiology, Department of Biology, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Delf Kah
- Biophysics, Department of Physics, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Christoph Mark
- Biophysics, Department of Physics, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Jan Dettmer
- Cell Biology, Department of Biology, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Theresa M Reimann
- Cell Biology, Department of Biology, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Richard C Gerum
- Biophysics, Department of Physics, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Anja Geitmann
- Department of Plant Science, McGill University, Macdonald Campus, Ste-Anne-de-Bellevue, Québec H9X 3V9, Canada
| | - Ben Fabry
- Biophysics, Department of Physics, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Petra Dietrich
- Molecular Plant Physiology, Department of Biology, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Benedikt Kost
- Cell Biology, Department of Biology, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
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39
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Guo J, Yang Z. Exocytosis and endocytosis: coordinating and fine-tuning the polar tip growth domain in pollen tubes. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2428-2438. [PMID: 32173729 PMCID: PMC7178420 DOI: 10.1093/jxb/eraa134] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 03/11/2020] [Indexed: 05/06/2023]
Abstract
Pollen tubes rapidly elongate, penetrate, and navigate through multiple female tissues to reach ovules for sperm delivery by utilizing a specialized form of polar growth known as tip growth. This process requires a battery of cellular activities differentially occurring at the apical growing region of the plasma membrane (PM), such as the differential cellular signaling involving calcium (Ca2+), phospholipids, and ROP-type Rho GTPases, fluctuation of ions and pH, exocytosis and endocytosis, and cell wall construction and remodeling. There is an emerging understanding of how at least some of these activities are coordinated and/or interconnected. The apical active ROP modulates exocytosis to the cell apex for PM and cell wall expansion differentially occurring at the tip. The differentiation of the cell wall involves at least the preferential distribution of deformable pectin polymers to the apex and non-deformable pectin polymers to the shank of pollen tubes, facilitating the apical cell expansion driven by high internal turgor pressure. Recent studies have generated inroads into how the ROP GTPase-based intracellular signaling is coordinated spatiotemporally with the external wall mechanics to maintain the tubular cell shape and how the apical cell wall mechanics are regulated to allow rapid tip growth while maintaining the cell wall integrity under the turgor pressure. Evidence suggests that exocytosis and endocytosis play crucial but distinct roles in this spatiotemporal coordination. In this review, we summarize recent advances in the regulation and coordination of the differential pectin distribution and the apical domain of active ROP by exocytosis and endocytosis in pollen tubes.
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Affiliation(s)
- Jingzhe Guo
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Department of Botany and Plant Sciences and Institute for Integrative Genome Biology, University of California, Riverside, CA, USA
| | - Zhenbiao Yang
- Department of Botany and Plant Sciences and Institute for Integrative Genome Biology, University of California, Riverside, CA, USA
- Correspondence:
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40
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Wang L, Triviño M, Lin Z, Carli J, Eaves DJ, Van Damme D, Nowack MK, Franklin-Tong VE, Bosch M. New opportunities and insights into Papaver self-incompatibility by imaging engineered Arabidopsis pollen. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2451-2463. [PMID: 32100005 PMCID: PMC7178406 DOI: 10.1093/jxb/eraa092] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 02/25/2020] [Indexed: 05/05/2023]
Abstract
Pollen tube growth is essential for plant reproduction. Their rapid extension using polarized tip growth provides an exciting system for studying this specialized type of growth. Self-incompatibility (SI) is a genetically controlled mechanism to prevent self-fertilization. Mechanistically, one of the best-studied SI systems is that of Papaver rhoeas (poppy). This utilizes two S-determinants: stigma-expressed PrsS and pollen-expressed PrpS. Interaction of cognate PrpS-PrsS triggers a signalling network, causing rapid growth arrest and programmed cell death (PCD) in incompatible pollen. We previously demonstrated that transgenic Arabidopsis thaliana pollen expressing PrpS-green fluorescent protein (GFP) can respond to Papaver PrsS with remarkably similar responses to those observed in incompatible Papaver pollen. Here we describe recent advances using these transgenic plants combined with genetically encoded fluorescent probes to monitor SI-induced cellular alterations, including cytosolic calcium, pH, the actin cytoskeleton, clathrin-mediated endocytosis (CME), and the vacuole. This approach has allowed us to study the SI response in depth, using multiparameter live-cell imaging approaches that were not possible in Papaver. This lays the foundations for new opportunities to elucidate key mechanisms involved in SI. Here we establish that CME is disrupted in self-incompatible pollen. Moreover, we reveal new detailed information about F-actin remodelling in pollen tubes after SI.
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Affiliation(s)
- Ludi Wang
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth, UK
| | - Marina Triviño
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth, UK
- Department of Plant Biotechnology and Genetics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Zongcheng Lin
- Department of Plant Biotechnology and Genetics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - José Carli
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth, UK
| | - Deborah J Eaves
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Daniёl Van Damme
- Department of Plant Biotechnology and Genetics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Moritz K Nowack
- Department of Plant Biotechnology and Genetics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Vernonica E Franklin-Tong
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
- Correspondence: or
| | - Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth, UK
- Correspondence: or
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Bibeau JP, Furt F, Mousavi SI, Kingsley JL, Levine MF, Tüzel E, Vidali L. In vivo interactions between myosin XI, vesicles and filamentous actin are fast and transient in Physcomitrella patens. J Cell Sci 2020; 133:jcs.234682. [PMID: 31964706 DOI: 10.1242/jcs.234682] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 01/07/2020] [Indexed: 12/25/2022] Open
Abstract
The actin cytoskeleton and active membrane trafficking machinery are essential for polarized cell growth. To understand the interactions between myosin XI, vesicles and actin filaments in vivo, we performed fluorescence recovery after photobleaching and showed that the dynamics of myosin XIa at the tip of the spreading earthmoss Physcomitrella patens caulonemal cells are actin-dependent and that 50% of myosin XI is bound to vesicles. To obtain single-particle information, we used variable-angle epifluorescence microscopy in protoplasts to demonstrate that protein myosin XIa and VAMP72-labeled vesicles localize in time and space over periods lasting only a few seconds. By tracking data with Hidden Markov modeling, we showed that myosin XIa and VAMP72-labeled vesicles exhibit short runs of actin-dependent directed transport. We also found that the interaction of myosin XI with vesicles is short-lived. Together, this vesicle-bound fraction, fast off-rate and short average distance traveled seem be crucial for the dynamic oscillations observed at the tip, and might be vital for regulation and recycling of the exocytosis machinery, while simultaneously promoting vesicle focusing and vesicle secretion at the tip, necessary for cell wall expansion.
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Affiliation(s)
- Jeffrey P Bibeau
- 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
| | - S Iman Mousavi
- Department of Physics, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - James L Kingsley
- Department of Physics, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Max F Levine
- Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Erkan Tüzel
- Department of Physics, Worcester Polytechnic Institute, Worcester, MA 01609, USA.,Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA 01609, USA.,Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA 19122, USA
| | - Luis Vidali
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA 01609, USA .,Bioinformatics and Computational Biology Program, Worcester Polytechnic Institute, Worcester, MA 01609, USA
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42
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Guo J, Yang Z. Measuring Exocytosis Rate in Arabidopsis Pollen Tubes Using Corrected Fluorescence Recovery After Photoconversion (cFRAPc) Technique. Methods Mol Biol 2020; 2160:293-306. [PMID: 32529445 DOI: 10.1007/978-1-0716-0672-8_21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Exocytosis is a fundamental process essential for many cellular functions by targeting signal peptides, proteins, and cell wall components to the plasma membrane (PM) or extracellular matrix. Conventional methods, such as FRAP, often underestimate the exocytosis rate of a specific molecule, because retrieval of the molecules from the PM by endocytosis can impact the measurement. To overcome this issue, we have previously established a novel method, corrected fluorescence recovery after photoconversion (cFRAPc), which allows us to accurately measure the exocytosis rate by monitoring both exocytosis-dependent and exocytosis-independent events. In this chapter, we provide detailed procedures for the cFRAPc method to measure the exocytosis rate of Arabidopsis receptor-like kinase PRK1 in pollen tubes. This method should be widely applicable to various cell types.
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Affiliation(s)
- Jingzhe Guo
- FAFU-UCR Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- Center for Plant Cell Biology, Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, CA, USA
| | - Zhenbiao Yang
- Center for Plant Cell Biology, Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, CA, USA.
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43
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Zhao L, Rehmani MS, Wang H. Exocytosis and Endocytosis: Yin-Yang Crosstalk for Sculpting a Dynamic Growing Pollen Tube Tip. FRONTIERS IN PLANT SCIENCE 2020; 11:572848. [PMID: 33123182 PMCID: PMC7573165 DOI: 10.3389/fpls.2020.572848] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/15/2020] [Indexed: 05/18/2023]
Abstract
The growing pollen tube has become one of the most fascinating model cell systems for investigations into cell polarity and polar cell growth in plants. Rapidly growing pollen tubes achieve tip-focused cell expansion by vigorous anterograde exocytosis, through which various newly synthesized macromolecules are directionally transported and deposited at the cell apex. Meanwhile, active retrograde endocytosis counter balances the exocytosis at the tip which is believed to recycle the excessive exocytic components for multiple rounds of secretion. Therefore, apical exocytosis and endocytosis are the frontline cellular processes which drive the polar growth of pollen tubes, although they represent opposite vesicular trafficking events with distinct underpinning mechanisms. Nevertheless, the molecular basis governing the spatiotemporal crosstalk and counterbalance of exocytosis and endocytosis during pollen tube polarization and growth remains elusive. Here we discuss recent insight into exocytosis and endocytosis in sculpturing high rates of polarized pollen tube growth. In addition, we especially introduce the novel integration of mathematical modeling in uncovering the mysteries of cell polarity and polar cell growth.
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Zhang L, Xing J, Lin J. At the intersection of exocytosis and endocytosis in plants. THE NEW PHYTOLOGIST 2019; 224:1479-1489. [PMID: 31230354 DOI: 10.1111/nph.16018] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/03/2019] [Indexed: 05/18/2023]
Abstract
Vesicle exocytosis and endocytosis control the activities and turnover of plasma membrane proteins required for signaling triggering or attenuating at the cell surface. In recent years, the diverse exocytic and endocytic trafficking pathways have been uncovered in plants. The balance between conventional and unconventional protein secretion provides an efficient strategy to respond to stress conditions. Similarly, clathrin-dependent and -independent endocytosis cooperatively regulate the dynamics of membrane proteins in response to environmental cues. In fact, many aspects of plant growth and development, such as tip growth, immune response, and protein polarity establishment, involve the tight deployment of exo-endocytic trafficking. However, our understanding of their intersection is limited. Here, we discuss recent advances in the molecular factors coupling plant exo-endocytic trafficking and the biological significance of balance between exocytosis and endocytosis in plants.
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Affiliation(s)
- Liang Zhang
- College of Life Science, Henan Normal University, Xinxiang, 453007, China
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jingjing Xing
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, 457001, China
| | - Jinxing Lin
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, 100083, China
- College of Biological Sciences & Biotechnology, Beijing Forestry University, Beijing, 100083, China
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45
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Słupianek A, Kasprowicz-Maluśki A, Myśkow E, Turzańska M, Sokołowska K. Endocytosis acts as transport pathway in wood. THE NEW PHYTOLOGIST 2019; 222:1846-1861. [PMID: 30548617 DOI: 10.1111/nph.15637] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 12/05/2018] [Indexed: 06/09/2023]
Abstract
In trees, dead and living cells of secondary xylem (wood) function collectively, rendering cell-to-cell communication challenging. Water and solutes are transported over long distances from the roots to the above-ground organs via vessels, the main component of wood, and then radially over short distances to the neighboring cells. This enables proper functioning of trees and integrates whole-plant activity. In this study, tracer loading, immunolocalization experiments and inhibitor assays were used to decipher the mechanisms enabling transport in wood of Acer pseudoplatanus (maple), Fraxinus excelsior (ash) and Populus tremula × tremuloides (poplar) trees. We show that tracer uptake from dead water-conducting vessels, elements of the apoplasm, to living vessel-associated cells (VACs) of the xylem parenchyma of the symplasm system proceeds via the endocytic pathway, including clathrin-mediated and clathrin-independent processes. These findings enhance our understanding of the transport pathways in complex wood tissue, providing experimental evidence of the involvement of VACs and endocytosis in radial uptake from vessels.
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Affiliation(s)
- Aleksandra Słupianek
- Department of Plant Developmental Biology, Institute of Experimental Biology, Faculty of Biological Sciences, University of Wrocław, Kanonia 6/8, Wrocław, 50-328, Poland
| | - Anna Kasprowicz-Maluśki
- Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, Poznań, 61-614, Poland
| | - Elżbieta Myśkow
- Department of Plant Developmental Biology, Institute of Experimental Biology, Faculty of Biological Sciences, University of Wrocław, Kanonia 6/8, Wrocław, 50-328, Poland
| | - Magdalena Turzańska
- Department of Plant Developmental Biology, Institute of Experimental Biology, Faculty of Biological Sciences, University of Wrocław, Kanonia 6/8, Wrocław, 50-328, Poland
| | - Katarzyna Sokołowska
- Department of Plant Developmental Biology, Institute of Experimental Biology, Faculty of Biological Sciences, University of Wrocław, Kanonia 6/8, Wrocław, 50-328, Poland
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Johnson MA, Harper JF, Palanivelu R. A Fruitful Journey: Pollen Tube Navigation from Germination to Fertilization. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:809-837. [PMID: 30822112 DOI: 10.1146/annurev-arplant-050718-100133] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In flowering plants, pollen tubes undergo tip growth to deliver two nonmotile sperm to the ovule where they fuse with an egg and central cell to achieve double fertilization. This extended journey involves rapid growth and changes in gene activity that manage compatible interactions with at least seven different cell types. Nearly half of the genome is expressed in haploid pollen, which facilitates genetic analysis, even of essential genes. These unique attributes make pollen an ideal system with which to study plant cell-cell interactions, tip growth, cell migration, the modulation of cell wall integrity, and gene expression networks. We highlight the signaling systems required for pollen tube navigation and the potential roles of Ca2+ signals. The dynamics of pollen development make sexual reproduction highly sensitive to heat stress. Understanding this vulnerability may generate strategies to improve seed crop yields that are under threat from climate change.
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Affiliation(s)
- Mark A Johnson
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA;
| | - Jeffrey F Harper
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada 89557, USA;
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Flowers TJ, Glenn EP, Volkov V. Could vesicular transport of Na+ and Cl- be a feature of salt tolerance in halophytes? ANNALS OF BOTANY 2019; 123:1-18. [PMID: 30247507 PMCID: PMC6344095 DOI: 10.1093/aob/mcy164] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/10/2018] [Indexed: 05/18/2023]
Abstract
Background Halophytes tolerate external salt concentrations of 200 mm and more, accumulating salt concentrations of 500 mm and more in their shoots; some, recretohalophytes, excrete salt through glands on their leaves. Ions are accumulated in central vacuoles, but the pathway taken by these ions from the outside of the roots to the vacuoles inside the cells is poorly understood. Do the ions cross membranes through ion channels and transporters or move in vesicles, or both? Vesicular transport from the plasma membrane to the vacuole would explain how halophytes avoid the toxicity of high salt concentrations on metabolism. There is also a role for vesicles in the export of ions via salt glands. Scope and Methods We have collected data on the fluxes of sodium and chloride ions in halophytes, based on the weight of the transporting organs and on the membrane area across which the flux occurs; the latter range from 17 nmol m-2 s-1 to 4.2 μmol m-2 s-1 and values up to 1 μmol m-2 s-1 need to be consistent with whatever transport system is in operation. We have summarized the sizes and rates of turnover of vesicles in plants, where clathrin-independent vesicles are 100 nm or more in diameter and can merge with the plasma membrane at rates of 100 s-1. We gathered evidence for vesicular transport of ions in halophytes and evaluated whether vesicular transport could account for the observable fluxes. Conclusions There is strong evidence in favour of vesicular transport in plants and circumstantial evidence in favour of the movement of ions in vesicles. Estimated rates of vesicle turnover could account for ion transport at the lower reported fluxes (around 20 nmol m-2 s-1), but the higher fluxes may require vesicles of the order of 1 μm or more in diameter. The very high fluxes reported in some salt glands might be an artefact of the way they were measured.
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Affiliation(s)
- Timothy J Flowers
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
- School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, Australia
| | - Edward P Glenn
- Environmental Research Laboratory of the University of Arizona, 1601 East, Airport Drive, Tucson, AZ, USA
| | - Vadim Volkov
- Faculty of Life Sciences and Computing, London Metropolitan University, London N7, UK
- Department of Plant Sciences, College of Agricultural and Environmental Sciences, University of California, Davis, CA, USA
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Zhou AP, Zong D, Gan PH, Zou XL, Fei X, Zhong YY, He CZ. Physiological Analysis and Transcriptome Profiling of Inverted Cuttings of Populus yunnanensis Reveal That Cell Wall Metabolism Plays a Crucial Role in Responding to Inversion. Genes (Basel) 2018; 9:E572. [PMID: 30477186 PMCID: PMC6316517 DOI: 10.3390/genes9120572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/15/2018] [Accepted: 11/20/2018] [Indexed: 01/24/2023] Open
Abstract
Inverted cuttings of Populus yunnanensis remain alive by rooting from the original morphological apex and sprouting from the base, but the lateral branches exhibit less vigorous growth than those of the upright plant. In this study, we examined the changes in hormone contents, oxidase activities, and transcriptome profiles between upright and inverted cuttings of P. yunnanensis. The results showed that the indole-3-acetic acid (IAA) and gibberellic acid (GA₃) contents were significantly lower in inverted cuttings than in upright cuttings only in the late growth period (September and October), while the abscisic acid (ABA) level was always similar between the two direction types. The biosynthesis of these hormones was surprisingly unrelated to the inversion of P. yunnanensis during the vegetative growth stage (July and August). Increased levels of peroxidases (PODs) encoded by 13 differentially expressed genes (DEGs) served as lignification promoters that protected plants against oxidative stress. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that most DEGs (107) were related to carbohydrate metabolism. Furthermore, altered activities of uridine diphosphate (UDP)-sugar pyrophosphorylase (USP, 15 DEGs) for nucleotide sugars, pectin methylesterase (PME, 7 DEGs) for pectin, and POD (13 DEGs) for lignin were important factors in the response of the trees to inversion, and these enzymes are all involved cell wall metabolism.
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Affiliation(s)
- An-Pei Zhou
- Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming 650224, China.
| | - Dan Zong
- Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming 650224, China.
| | - Pei-Hua Gan
- Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming 650224, China.
| | - Xin-Lian Zou
- Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming 650224, China.
| | - Xuan Fei
- Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming 650224, China.
| | - Yuan-Yuan Zhong
- Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming 650224, China.
| | - Cheng-Zhong He
- Key Laboratory for Forest Genetic and Tree Improvement and Propagation in Universities of Yunnan Province, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming 650224, China.
- Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming 650224, China.
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Herbell S, Gutermuth T, Konrad KR. An interconnection between tip-focused Ca 2+ and anion homeostasis controls pollen tube growth. PLANT SIGNALING & BEHAVIOR 2018; 13:e1529521. [PMID: 30307369 PMCID: PMC6279333 DOI: 10.1080/15592324.2018.1529521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 05/12/2023]
Abstract
Plant reproduction is the basis for economically relevant food production. It relies on pollen tube (PTs) growth into the female flower organs for successful fertilization. The high cytosolic Ca2+ concentration ([Ca2+]cyt) at the PT tip is sensed by Ca2+-dependent protein kinases (CPKs) that in turn activate R- and S-type anion channels to control polar growth. Lanthanum, a blocker for plant Ca2+-permeable channels was used here to demonstrate a strict dependency for anion channel activation through high PT tip [Ca2+]cyt. We visualized this relationship by live-cell anion imaging and concurrent triggering of Ca2+-elevations with the two-electrode voltage-clamp (TEVC) technique. The anion efflux provoked by a TEVC-triggered [Ca2+]cyt increase was abolished by Lanthanum and was followed by an overall rise in the cytosolic anion concentration. An interrelation between Ca2+ and anion homeostasis occurred also on the transcript level of CPKs and anion channels. qRT-PCR analysis demonstrated a co-regulation of anion channels and CPKs in media with different Cl- and NO3- compositions. Our data provides strong evidence for the importance of a Ca2+-dependent anion channel regulation and point to a synchronized adjustment of CPK and anion channel transcript levels to fine-tune anion efflux at the PT tip.
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Affiliation(s)
- Sarah Herbell
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| | - Timo Gutermuth
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
| | - Kai Robert Konrad
- University of Wuerzburg, Julius-Von-Sachs Institute for Biosciences, Department of Botany I, Wuerzburg, Germany
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50
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Zhang Q, van Wijk R, Zarza X, Shahbaz M, van Hooren M, Guardia A, Scuffi D, García-Mata C, Van den Ende W, Hoffmann-Benning S, Haring MA, Laxalt AM, Munnik T. Knock-Down of Arabidopsis PLC5 Reduces Primary Root Growth and Secondary Root Formation While Overexpression Improves Drought Tolerance and Causes Stunted Root Hair Growth. PLANT & CELL PHYSIOLOGY 2018; 59:2004-2019. [PMID: 30107538 DOI: 10.1093/pcp/pcy120] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/14/2018] [Indexed: 05/12/2023]
Abstract
Phospholipase C (PLC) is a well-known signaling enzyme in metazoans that hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) to produce inositol 1,4,5-trisphosphate and diacylglycerol as second messengers involved in mutiple processes. Plants contain PLC too, but relatively little is known about its function there. The model system Arabidopsis thaliana contains nine PLC genes. Reversed genetics have implicated several roles for PLCs in plant development and stress signaling. Here, PLC5 is functionally addressed. Promoter-β-glucuronidase (GUS) analyses revealed expression in roots, leaves and flowers, predominantly in vascular tissue, most probably phloem companion cells, but also in guard cells, trichomes and root apical meristem. Only one plc5-1 knock-down mutant was obtained, which developed normally but grew more slowly and exhibited reduced primary root growth and decreased lateral root numbers. These phenotypes could be complemented by expressing the wild-type gene behind its own promoter. Overexpression of PLC5 (PLC5-OE) using the UBQ10 promoter resulted in reduced primary and secondary root growth, stunted root hairs, decreased stomatal aperture and improved drought tolerance. PLC5-OE lines exhibited strongly reduced phosphatidylinositol 4-monophosphate (PIP) and PIP2 levels and increased amounts of phosphatidic acid, indicating enhanced PLC activity in vivo. Reduced PIP2 levels and stunted root hair growth of PLC5-OE seedlings could be recovered by inducible overexpression of a root hair-specific PIP 5-kinase, PIP5K3. Our results show that PLC5 is involved in primary and secondary root growth and that its overexpression improves drought tolerance. Independently, we provide new evidence that PIP2 is essential for the polar tip growth of root hairs.
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Affiliation(s)
- Qianqian Zhang
- Section Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
- Section Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
| | - Ringo van Wijk
- Section Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
- Section Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
| | - Xavier Zarza
- Section Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
- Section Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
| | - Muhammad Shahbaz
- Section Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
| | - Max van Hooren
- Section Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
| | - Aisha Guardia
- Instituto de Investigaciones Biológicas (IIB-CONICET-UNMdP), Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Denise Scuffi
- Instituto de Investigaciones Biológicas (IIB-CONICET-UNMdP), Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Carlos García-Mata
- Instituto de Investigaciones Biológicas (IIB-CONICET-UNMdP), Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Wim Van den Ende
- Laboratory of Molecular Plant Biology, University of Leuven, Leuven, Belgium
| | - Susanne Hoffmann-Benning
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Michel A Haring
- Section Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
| | - Ana M Laxalt
- Instituto de Investigaciones Biológicas (IIB-CONICET-UNMdP), Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Teun Munnik
- Section Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
- Section Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, XH, The Netherlands
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