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Municio-Diaz C, Muller E, Drevensek S, Fruleux A, Lorenzetti E, Boudaoud A, Minc N. Mechanobiology of the cell wall – insights from tip-growing plant and fungal cells. J Cell Sci 2022; 135:280540. [DOI: 10.1242/jcs.259208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ABSTRACT
The cell wall (CW) is a thin and rigid layer encasing the membrane of all plant and fungal cells. It ensures mechanical integrity by bearing mechanical stresses derived from large cytoplasmic turgor pressure, contacts with growing neighbors or growth within restricted spaces. The CW is made of polysaccharides and proteins, but is dynamic in nature, changing composition and geometry during growth, reproduction or infection. Such continuous and often rapid remodeling entails risks of enhanced stress and consequent damages or fractures, raising the question of how the CW detects and measures surface mechanical stress and how it strengthens to ensure surface integrity? Although early studies in model fungal and plant cells have identified homeostatic pathways required for CW integrity, recent methodologies are now allowing the measurement of pressure and local mechanical properties of CWs in live cells, as well as addressing how forces and stresses can be detected at the CW surface, fostering the emergence of the field of CW mechanobiology. Here, using tip-growing cells of plants and fungi as case study models, we review recent progress on CW mechanosensation and mechanical regulation, and their implications for the control of cell growth, morphogenesis and survival.
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Affiliation(s)
- Celia Municio-Diaz
- Université de Paris, CNRS, Institut Jacques Monod 1 , F-75006 Paris , France
- Equipe Labellisée LIGUE Contre le Cancer 2 , 75013 Paris , France
| | - Elise Muller
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Stéphanie Drevensek
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Antoine Fruleux
- LPTMS, CNRS, Université Paris-Saclay 4 , 91405 Orsay , France
| | - Enrico Lorenzetti
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Arezki Boudaoud
- LadHyX, CNRS, Ecole polytechnique, Institut Polytechnique de Paris 3 , 91128 Palaiseau Cedex , France
| | - Nicolas Minc
- Université de Paris, CNRS, Institut Jacques Monod 1 , F-75006 Paris , France
- Equipe Labellisée LIGUE Contre le Cancer 2 , 75013 Paris , France
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2
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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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Guo J, He J, Dehesh K, Cui X, Yang Z. CamelliA-based simultaneous imaging of Ca2+ dynamics in subcellular compartments. PLANT PHYSIOLOGY 2022; 188:2253-2271. [PMID: 35218352 PMCID: PMC8968278 DOI: 10.1093/plphys/kiac020] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
As a universal second messenger, calcium (Ca2+) transmits specific cellular signals via a spatiotemporal signature generated from its extracellular source and internal stores. Our knowledge of the mechanisms underlying the generation of a Ca2+ signature is hampered by limited tools for simultaneously monitoring dynamic Ca2+ levels in multiple subcellular compartments. To overcome the limitation and to further improve spatiotemporal resolutions, we have assembled a molecular toolset (CamelliA lines) in Arabidopsis (Arabidopsis thaliana) that enables simultaneous and high-resolution monitoring of Ca2+ dynamics in multiple subcellular compartments through imaging different single-colored genetically encoded calcium indicators. We uncovered several Ca2+ signatures in three types of Arabidopsis cells in response to internal and external cues, including rapid oscillations of cytosolic Ca2+ and apical plasma membrane Ca2+ influx in fast-growing Arabidopsis pollen tubes, the spatiotemporal relationship of Ca2+ dynamics in four subcellular compartments of root epidermal cells challenged with salt, and a shockwave-like Ca2+ wave propagating in laser-wounded leaf epidermis. These observations serve as a testimony to the wide applicability of the CamelliA lines for elucidating the subcellular sources contributing to the Ca2+ signatures in plants.
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Affiliation(s)
- Jingzhe Guo
- Institute for Integrative Genome Biology, University of California, Riverside, 92521 California, USA
- Department of Botany and Plant Sciences, University of California, Riverside, 92521 California, USA
| | - Jiangman He
- Institute for Integrative Genome Biology, University of California, Riverside, 92521 California, USA
- Department of Botany and Plant Sciences, University of California, Riverside, 92521 California, USA
| | - Katayoon Dehesh
- Institute for Integrative Genome Biology, University of California, Riverside, 92521 California, USA
- Department of Botany and Plant Sciences, University of California, Riverside, 92521 California, USA
| | - Xinping Cui
- Institute for Integrative Genome Biology, University of California, Riverside, 92521 California, USA
- Department of Statistics, University of California, Riverside, 92521 California, USA
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4
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Scheible N, Yoon GM, McCubbin AG. Calmodulin Domain Protein Kinase PiCDPK1 Regulates Pollen Tube Growth Polarity through Interaction with RhoGDI. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11030254. [PMID: 35161234 PMCID: PMC8838988 DOI: 10.3390/plants11030254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 05/14/2023]
Abstract
The pollen-specific calcium-dependent protein kinase PiCDPK1 of Petunia inflata has previously been shown to regulate polarity in tip growth in pollen tubes. Here we report the identification of a Rho Guanine Dissociation Inhibitor (PiRhoGDI1) as a PiCDPK1 interacting protein. We demonstrate that PiRhoGDI1 and PiCDPK1 interact in a yeast 2-hybrid assay, as well as in an in vitro pull-down assay, and that PiRhoGDI1 is phosphorylated by PiCDPK1 in vitro. We further demonstrate the PiRhoGDI1 is capable of rescuing the loss of growth polarity phenotype caused by over-expressing PiCDPK1 in vivo using stable transgenic plants. We confirmed that PiRhoGDI1 interacts with a pollen-expressed ROP GTPase isoform consistent with the established role of RhoGDIs in negatively regulating GTPases through their membrane removal and locking them in an inactive cytosolic complex. ROP is a central regulator of polarity in tip growth, upstream of Ca2+, and PiCDPK1 over-expression has been previously reported to lead to dramatic elevation of cytosolic Ca2+ through a positive feedback loop. The discovery that PiCDPK1 impacts ROP regulation via PiRhoGDI1 suggests that PiCDPK1 acts as RhoGDI displacement factor and leads us to propose a model which we hypothesize regulates the rapid recycling of ROP GTPase at the pollen tube tip.
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5
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Li K, Prada J, Damineli DSC, Liese A, Romeis T, Dandekar T, Feijó JA, Hedrich R, Konrad KR. An optimized genetically encoded dual reporter for simultaneous ratio imaging of Ca 2+ and H + reveals new insights into ion signaling in plants. THE NEW PHYTOLOGIST 2021; 230:2292-2310. [PMID: 33455006 PMCID: PMC8383442 DOI: 10.1111/nph.17202] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/23/2020] [Indexed: 05/07/2023]
Abstract
Whereas the role of calcium ions (Ca2+ ) in plant signaling is well studied, the physiological significance of pH-changes remains largely undefined. Here we developed CapHensor, an optimized dual-reporter for simultaneous Ca2+ and pH ratio-imaging and studied signaling events in pollen tubes (PTs), guard cells (GCs), and mesophyll cells (MCs). Monitoring spatio-temporal relationships between membrane voltage, Ca2+ - and pH-dynamics revealed interconnections previously not described. In tobacco PTs, we demonstrated Ca2+ -dynamics lag behind pH-dynamics during oscillatory growth, and pH correlates more with growth than Ca2+ . In GCs, we demonstrated abscisic acid (ABA) to initiate stomatal closure via rapid cytosolic alkalization followed by Ca2+ elevation. Preventing the alkalization blocked GC ABA-responses and even opened stomata in the presence of ABA, disclosing an important pH-dependent GC signaling node. In MCs, a flg22-induced membrane depolarization preceded Ca2+ -increases and cytosolic acidification by c. 2 min, suggesting a Ca2+ /pH-independent early pathogen signaling step. Imaging Ca2+ and pH resolved similar cytosol and nuclear signals and demonstrated flg22, but not ABA and hydrogen peroxide to initiate rapid membrane voltage-, Ca2+ - and pH-responses. We propose close interrelation in Ca2+ - and pH-signaling that is cell type- and stimulus-specific and the pH having crucial roles in regulating PT growth and stomata movement.
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Affiliation(s)
- Kunkun Li
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, Wuerzburg 97082, Germany
| | - Juan Prada
- Department of Bioinformatics, University of Wuerzburg, Wuerzburg 97074, Germany
| | - Daniel S. C. Damineli
- Department of Cell Biology & Molecular Genetics, University of Maryland, 2136 Bioscience Research Bldg, College Park, MD 20742-5815, USA
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP 01246-903, Brazil
| | - Anja Liese
- Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
| | - Tina Romeis
- Leibniz Institute of Plant Biochemistry, Halle (Saale) 06120, Germany
| | - Thomas Dandekar
- Department of Bioinformatics, University of Wuerzburg, Wuerzburg 97074, Germany
| | - José A. Feijó
- Department of Cell Biology & Molecular Genetics, University of Maryland, 2136 Bioscience Research Bldg, College Park, MD 20742-5815, USA
| | - Rainer Hedrich
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, Wuerzburg 97082, Germany
| | - Kai Robert Konrad
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, Wuerzburg 97082, Germany
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6
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Hayashi M, Palmgren M. The quest for the central players governing pollen tube growth and guidance. PLANT PHYSIOLOGY 2021; 185:682-693. [PMID: 33793904 PMCID: PMC8133568 DOI: 10.1093/plphys/kiaa092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 12/06/2020] [Indexed: 05/02/2023]
Abstract
Recent insights into the mechanism of pollen tube growth and guidance point to the importance of H+ dynamics, which are regulated by the plasma membrane H+-ATPase.
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Affiliation(s)
- Maki Hayashi
- Department for Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Copenhagen, Denmark
| | - Michael Palmgren
- Department for Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Copenhagen, Denmark
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000,China
- Author for communication:
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7
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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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8
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Zhao W, Qu X, Zhuang Y, Wang L, Bosch M, Franklin-Tong VE, Xue Y, Huang S. Villin controls the formation and enlargement of punctate actin foci in pollen tubes. J Cell Sci 2020; 133:jcs237404. [PMID: 32051284 DOI: 10.1242/jcs.237404] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 02/01/2020] [Indexed: 11/20/2022] Open
Abstract
Self-incompatibility (SI) in the poppy Papaver rhoeas triggers dramatic alterations in actin within pollen tubes. However, how these actin alterations are mechanistically achieved remains largely unexplored. Here, we used treatment with the Ca2+ ionophore A23187 to mimic the SI-induced elevation in cytosolic Ca2+ and trigger formation of the distinctive F-actin foci. Live-cell imaging revealed that this remodeling involves F-actin fragmentation and depolymerization, accompanied by the rapid formation of punctate actin foci and subsequent increase in their size. We established that actin foci are generated and enlarged from crosslinking of fragmented actin filament structures. Moreover, we show that villins associate with actin structures and are involved in this actin reorganization process. Notably, we demonstrate that Arabidopsis VILLIN5 promotes actin depolymerization and formation of actin foci by fragmenting actin filaments, and controlling the enlargement of actin foci via bundling of actin filaments. Our study thus uncovers important novel insights about the molecular players and mechanisms involved in forming the distinctive actin foci in pollen tubes.
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Affiliation(s)
- Wanying Zhao
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xiaolu Qu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Yuhui Zhuang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ludi Wang
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth, SY23 3EE, UK
| | - Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth, SY23 3EE, UK
| | - Vernonica E Franklin-Tong
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Yongbiao Xue
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shanjin Huang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
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9
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Choudhary A, Kumar A, Kaur N. ROS and oxidative burst: Roots in plant development. PLANT DIVERSITY 2020; 42:33-43. [PMID: 32140635 PMCID: PMC7046507 DOI: 10.1016/j.pld.2019.10.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/02/2019] [Accepted: 10/10/2019] [Indexed: 05/03/2023]
Abstract
Reactive oxygen species (ROS) are widely generated in various redox reactions in plants. In earlier studies, ROS were considered toxic byproducts of aerobic metabolism. In recent years, it has become clear that ROS act as plant signaling molecules that participate in various processes such as growth and development. Several studies have elucidated the roles of ROS from seed germination to senescence. However, there is much to discover about the diverse roles of ROS as signaling molecules and their mechanisms of sensing and response. ROS may provide possible benefits to plant physiological processes by supporting cellular proliferation in cells that maintain basal levels prior to oxidative effects. Although ROS are largely perceived as either negative by-products of aerobic metabolism or makers for plant stress, elucidating the range of functions that ROS play in growth and development still require attention.
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10
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Santiago JP, Sharkey TD. Pollen development at high temperature and role of carbon and nitrogen metabolites. PLANT, CELL & ENVIRONMENT 2019; 42:2759-2775. [PMID: 31077385 DOI: 10.1111/pce.13576] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/06/2019] [Accepted: 05/06/2019] [Indexed: 05/11/2023]
Abstract
Fruit and seed crop production heavily relies on successful stigma pollination, pollen tube growth, and fertilization of female gametes. These processes depend on production of viable pollen grains, a process sensitive to high-temperature stress. Therefore, rising global temperatures threaten worldwide crop production. Close observation of plant development shows that high-temperature stress causes morpho-anatomical changes in male reproductive tissues that contribute to reproductive failure. These changes include early tapetum degradation, anther indehiscence, and deformity of pollen grains, all of which are contributing factors to pollen fertility. At the molecular level, reactive oxygen species (ROS) accumulate when plants are subjected to high temperatures. ROS is a signalling molecule that can be beneficial or detrimental for plant cells depending on its balance with the endogenous cellular antioxidant system. Many metabolites have been linked with ROS over the years acting as direct scavengers or molecular stabilizers that promote antioxidant enzyme activity. This review highlights recent advances in research on anther and pollen development and how these might explain the aberrations seen during high-temperature stress; recent work on the role of nitrogen and carbon metabolites in anther and pollen development is discussed including their potential role at high temperature.
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Affiliation(s)
- James P Santiago
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan, 48824
| | - Thomas D Sharkey
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, 48824
- Plant Resilience Institute, Michigan State University, East Lansing, Michigan, 48824
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11
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Scheible N, McCubbin A. Signaling in Pollen Tube Growth: Beyond the Tip of the Polarity Iceberg. PLANTS (BASEL, SWITZERLAND) 2019; 8:E156. [PMID: 31181594 PMCID: PMC6630365 DOI: 10.3390/plants8060156] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/04/2019] [Accepted: 06/06/2019] [Indexed: 12/15/2022]
Abstract
The coordinated growth of pollen tubes through floral tissues to deliver the sperm cells to the egg and facilitate fertilization is a highly regulated process critical to the Angiosperm life cycle. Studies suggest that the concerted action of a variety of signaling pathways underlies the rapid polarized tip growth exhibited by pollen tubes. Ca2+ and small GTPase-mediated pathways have emerged as major players in the regulation of pollen tube growth. Evidence suggests that these two signaling pathways not only integrate with one another but also with a variety of other important signaling events. As we continue to elucidate the mechanisms involved in pollen tube growth, there is a growing importance in taking a holistic approach to studying these pathways in order to truly understand how tip growth in pollen tubes is orchestrated and maintained. This review considers our current state of knowledge of Ca2+-mediated and GTPase signaling pathways in pollen tubes, how they may intersect with one another, and other signaling pathways involved. There will be a particular focus on recent reports that have extended our understanding in these areas.
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Affiliation(s)
- Nolan Scheible
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
| | - Andrew McCubbin
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
- Center for Reproductive Biology, Pullman, WA, 99164, USA.
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12
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Zhang R, Qu X, Zhang M, Jiang Y, Dai A, Zhao W, Cao D, Lan Y, Yu R, Wang H, Huang S. The Balance between Actin-Bundling Factors Controls Actin Architecture in Pollen Tubes. iScience 2019; 16:162-176. [PMID: 31181400 PMCID: PMC6556835 DOI: 10.1016/j.isci.2019.05.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 04/29/2019] [Accepted: 05/21/2019] [Indexed: 11/19/2022] Open
Abstract
How actin-bundling factors cooperatively regulate shank-localized actin bundles remains largely unexplored. Here we demonstrate that FIM5 and PLIM2a/PLIM2b decorate shank-localized actin bundles and that loss of function of PLIM2a and/or PLIM2b suppresses phenotypes associated with fim5 mutants. Specifically, knockout of PLIM2a and/or PLIM2b partially suppresses the disorganized actin bundle and intracellular trafficking phenotype in fim5 pollen tubes. PLIM2a/PLIM2b generates thick but loosely packed actin bundles, whereas FIM5 generates thin but tight actin bundles that tend to be cross-linked into networks in vitro. Furthermore, PLIM2a/PLIM2b and FIM5 compete for binding to actin filaments in vitro, and PLIM2a/PLIM2b decorate disorganized actin bundles in fim5 pollen tubes. These data together suggest that the disorganized actin bundles in fim5 mutants are at least partially due to gain of function of PLIM2a/PLIM2b. Our data suggest that the balance between FIM5 and PLIM2a/PLIM2b is crucial for the normal bundling and organization of shank-localized actin bundles in pollen tubes. The transcription of PLIM2a and PLIM2b is upregulated in fim5 pollen tubes Downregulation of PLIM2a and/or PLIM2b suppresses the defects in fim5 pollen tubes Both FIM5 and PLIM2a/PLIM2b decorate shank-localized actin filaments FIM5 can inhibit the binding of PLIM2a and PLIM2b to actin filaments
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Affiliation(s)
- Ruihui Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaolu Qu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Meng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yuxiang Jiang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Anbang Dai
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wanying Zhao
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Dai Cao
- School of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Yaxian Lan
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Rong Yu
- School of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Hongwei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shanjin Huang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
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13
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Zheng RH, Su SD, Xiao H, Tian HQ. Calcium: A Critical Factor in Pollen Germination and Tube Elongation. Int J Mol Sci 2019; 20:E420. [PMID: 30669423 PMCID: PMC6358865 DOI: 10.3390/ijms20020420] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/20/2018] [Accepted: 12/25/2018] [Indexed: 02/07/2023] Open
Abstract
Pollen is the male gametophyte of higher plants. Its major function is to deliver sperm cells to the ovule to ensure successful fertilization. During this process, many interactions occur among pollen tubes and pistil cells and tissues, and calcium ion (Ca2+) dynamics mediate these interactions among cells to ensure that pollen reaches the embryo sac. Although the precise functions of Ca2+ dynamics in the cells are unknown, we can speculate about its roles on the basis of its spatial and temporal characteristics during these interactions. The results of many studies indicate that calcium is a critical element that is strongly related to pollen germination and pollen tube growth.
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Affiliation(s)
- Ren Hua Zheng
- The Key Laboratory of Timber Forest Breeding and Cultivation for Mountainous Areas in Southern China, Fujian Academy of Forestry, Fuzhou 350012, China.
| | - Shun De Su
- The Key Laboratory of Timber Forest Breeding and Cultivation for Mountainous Areas in Southern China, Fujian Academy of Forestry, Fuzhou 350012, China.
| | - Hui Xiao
- The Key Laboratory of Timber Forest Breeding and Cultivation for Mountainous Areas in Southern China, Fujian Academy of Forestry, Fuzhou 350012, China.
| | - Hui Qiao Tian
- School of Life Sciences, Xiamen University, Xiamen 361102, China.
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14
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Wu Y, Qin B, Feng K, Yan R, Kang E, Liu T, Shang Z. Extracellular ATP promoted pollen germination and tube growth of Nicotiana tabacum through promoting K + and Ca 2+ absorption. PLANT REPRODUCTION 2018; 31:399-410. [PMID: 29934740 DOI: 10.1007/s00497-018-0341-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 06/15/2018] [Indexed: 05/15/2023]
Abstract
Extracellular ATP (eATP) plays an essential role in plant growth, development, and stress tolerance. Here, we report that eATP participated in Nicotiana tabacum pollen germination (PG) and pollen tube growth (PTG) by regulating K+ and Ca2+ influx. Exogenous ATP or ADP effectively promoted PG and PTG in a dose-dependent manner; weakly hydrolysable ATP analog (ATPγS) showed a similar effect. AMP, adenosine, adenine, and phosphate did not affect PG or PTG. Within a certain range, higher concentrations of K+ or Ca2+ in the medium increased the effect of ATP in promoting PG and PTG. However, in mediums containing K+ or Ca2+ concentrations above this range, the effect of ATP was reversed, resulting in PG and PTG inhibition. Ca2+ chelators (EGTA), Ca2+ channel blockers, and K+ channel blockers suppressed ATP-promoted PG and PTG. Results from a patch clamp showed that ATP activated a K+ and Ca2+ influx in pollen protoplasts. These results suggest that, as an apoplastic signal, eATP may be involved in PG and PTG via regulating Ca2+ and K+ absorption.
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Affiliation(s)
- Yansheng Wu
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
- Department of Chemistry Engineering and Biological Technology, Xingtai University, Xingtai, 054001, Hebei, China
| | - Baozhi Qin
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Kaili Feng
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Ruolin Yan
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Erfang Kang
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Ting Liu
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China
| | - Zhonglin Shang
- Hebei Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Molecular and Cellular Biology of the Ministry of Education, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, Hebei, China.
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15
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Diao M, Qu X, Huang S. Calcium imaging in Arabidopsis pollen cells using G-CaMP5. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2018; 60:897-906. [PMID: 29424471 DOI: 10.1111/jipb.12642] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 02/07/2018] [Indexed: 05/18/2023]
Abstract
Calcium (Ca2+ ) signaling has been implicated in pollen germination and pollen tube growth. To date, however, we still know very little about how exactly Ca2+ signaling links to various physiological subcellular processes during pollen germination and pollen tube growth. Given that Ca2+ signaling is tightly related to the cytosolic concentration and dynamics of Ca2+ , it is vital to trace the dynamic changes in Ca2+ levels in order to decode Ca2+ signaling. Here, we demonstrate that G-CaMP5 serves well as an indicator for monitoring cytosolic Ca2+ dynamics in pollen cells. Using this probe, we show that cytosolic Ca2+ changes dramatically during pollen germination, and, as reported previously, Ca2+ forms a tip-focused gradient in the pollen tube and undergoes oscillation in the tip region during pollen tube growth. In particular, using G-CaMP5 allowed us to capture the dynamic changes in the cytosolic Ca2+ concentration ([Ca2+ ]cyt ) in pollen tubes in response to various exogenous treatments. Our data suggest that G-CaMP5 is a suitable probe for monitoring the dynamics of [Ca2+ ]cyt in pollen cells.
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Affiliation(s)
- Min Diao
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaolu Qu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shanjin Huang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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16
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Kaminskyj SGW, Heath IB. Studies onSaprolegnia feraxsuggest the general importance of the cytoplasm in determining hyphal morphology. Mycologia 2018. [DOI: 10.1080/00275514.1996.12026621] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Susan G. W. Kaminskyj
- Department of Biology, York University, 4700 Keele Street, North York, Ontario, Canada, M3J 1P3
| | - I. Brent Heath
- Department of Biology, York University, 4700 Keele Street, North York, Ontario, Canada, M3J 1P3
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17
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Punjabi M, Bharadvaja N, Sachdev A, Krishnan V. Molecular characterization, modeling, and docking analysis of late phytic acid biosynthesis pathway gene, inositol polyphosphate 6-/ 3-/ 5-kinase, a potential candidate for developing low phytate crops. 3 Biotech 2018; 8:344. [PMID: 30073129 PMCID: PMC6064606 DOI: 10.1007/s13205-018-1343-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 07/06/2018] [Indexed: 01/08/2023] Open
Abstract
The coding sequence of inositol polyphosphate 6-/3-/5-kinase (GmIPK2) gene was identified and cloned from popular Indian soybean cultivar Pusa-16. The clone was predicted to encode 279 amino acids long, 30.97 kDa protein. Multiple sequence alignment revealed an inositol phosphate-binding motif, PxxxDxKxG throughout the IPK2 sequences along with other motifs unique to inositol phosphate kinase superfamily. Eight α-helices and eight β-strands in antiparallel β-sheets arrangement were predicted in the secondary structure of GmIPK2. The temporal analysis of GmIPK2 revealed maximum expression in the seed tissues during later stages of development while spatially the transcript levels were lowest in leaf and stem tissues. Endosperm-specific cis-regulatory motifs (GCN4 and Skn_1) which support high levels of expression, as observed in the developing seeds, were detected in its promoter region. The protein structure of GmIPK2 was modeled based on the crystal structure of inositol polyphosphate multikinase from Arabidopsis thaliana (PDB:4FRF) and subsequently docked with inositol phosphate ligands (PDB: 5GUG-I3P and PDB: 4A69-I0P). Molecular dynamics (MD) simulation established the structural stability of both, modeled enzyme and ligand-bound complexes. Docking in combination with trajectory analysis for 50 ns MD run confirmed the participation of Lys105, Lys126 and Arg153 residues in the formation of a network of hydrogen bonds to stabilize the ligand-receptor interaction. Results of the present study thus provide valuable information on structural and functional aspects of GmIPK2 which shall assist in strategizing our long-term goal of achieving phytic acid reduction in soybean by genetic modification of its biosynthetic pathway to develop a nutritionally enhanced crop in the future.
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Affiliation(s)
- Mansi Punjabi
- Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), New Delhi, 110042 India
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Navneeta Bharadvaja
- Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), New Delhi, 110042 India
| | - Archana Sachdev
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Veda Krishnan
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi, 110012 India
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18
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Chen KW, Marusciac L, Tamas PT, Valenta R, Panaitescu C. Ragweed Pollen Allergy: Burden, Characteristics, and Management of an Imported Allergen Source in Europe. Int Arch Allergy Immunol 2018; 176:163-180. [PMID: 29788026 DOI: 10.1159/000487997] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/22/2018] [Indexed: 12/30/2022] Open
Abstract
Ambrosia artemisiifolia, also known as common or short ragweed, is an invasive annual flowering herbaceous plant that has its origin in North America. Nowadays, ragweed can be found in many areas worldwide. Ragweed pollen is known for its high potential to cause type I allergic reactions in late summer and autumn and represents a major health problem in America and several countries in Europe. Climate change and urbanization, as well as long distance transport capacity, enhance the spread of ragweed pollen. Therefore ragweed is becoming domestic in non-invaded areas which in turn will increase the sensitization rate. So far 11 ragweed allergens have been described and, according to IgE reactivity, Amb a 1 and Amb a 11 seem to be major allergens. Sensitization rates of the other allergens vary between 10 and 50%. Most of the allergens have already been recombinantly produced, but most of them have not been characterized regarding their allergenic activity, therefore no conclusion on the clinical relevance of all the allergens can be made, which is important and necessary for an accurate diagnosis. Pharmacotherapy is the most common treatment for ragweed pollen allergy but fails to impact on the course of allergy. Allergen-specific immunotherapy (AIT) is the only causative and disease-modifying treatment of allergy with long-lasting effects, but currently it is based on the administration of ragweed pollen extract or Amb a 1 only. In order to improve ragweed pollen AIT, new strategies are required with higher efficacy and safety.
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Affiliation(s)
- Kuan-Wei Chen
- OncoGen Center, Pius Brinzeu County Clinical Emergency Hospital, Timisoara, Romania.,Division of Immunopathology, Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Laura Marusciac
- OncoGen Center, Pius Brinzeu County Clinical Emergency Hospital, Timisoara, Romania.,Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
| | - Paul Tudor Tamas
- OncoGen Center, Pius Brinzeu County Clinical Emergency Hospital, Timisoara, Romania.,Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
| | - Rudolf Valenta
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Carmen Panaitescu
- OncoGen Center, Pius Brinzeu County Clinical Emergency Hospital, Timisoara, Romania.,Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
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19
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Zhang X, Tang X, Wang M, Zhang W, Zhou B, Wang Y. ROS and calcium signaling mediated pathways involved in stress responses of the marine microalgae Dunaliella salina to enhanced UV-B radiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017. [DOI: 10.1016/j.jphotobiol.2017.05.038] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Damineli DSC, Portes MT, Feijó JA. Oscillatory signatures underlie growth regimes in Arabidopsis pollen tubes: computational methods to estimate tip location, periodicity, and synchronization in growing cells. JOURNAL OF EXPERIMENTAL BOTANY 2017. [PMID: 28369603 DOI: 10.5061/dryad.6806c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Oscillations in pollen tubes have been reported for many cellular processes, including growth, extracellular ion fluxes, and cytosolic ion concentrations. However, there is a shortage of quantitative methods to measure and characterize the different dynamic regimes observed. Herein, a suite of open-source computational methods and original algorithms were integrated into an automated analysis pipeline that we employed to characterize specific oscillatory signatures in pollen tubes of Arabidopsis thaliana (Col-0). Importantly, it enabled us to detect and quantify a Ca2+ spiking behaviour upon growth arrest and synchronized oscillations involving growth, extracellular H+ fluxes, and cytosolic Ca2+, providing the basis for novel hypotheses. Our computational approach includes a new tip detection method with subpixel resolution using linear regression, showing improved ability to detect oscillations when compared to currently available methods. We named this data analysis pipeline 'Computational Heuristics for Understanding Kymographs and aNalysis of Oscillations Relying on Regression and Improved Statistics', or CHUKNORRIS. It can integrate diverse data types (imaging, electrophysiology), extract quantitative and time-explicit estimates of oscillatory characteristics from isolated time series (period and amplitude) or pairs (phase relationships and delays), and evaluate their synchronization state. Here, its performance is tested with ratiometric and single channel kymographs, ion flux data, and growth rate analysis.
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Affiliation(s)
- Daniel S C Damineli
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Maria Teresa Portes
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - José A Feijó
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
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21
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Damineli DSC, Portes MT, Feijó JA. Oscillatory signatures underlie growth regimes in Arabidopsis pollen tubes: computational methods to estimate tip location, periodicity, and synchronization in growing cells. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3267-3281. [PMID: 28369603 PMCID: PMC5853864 DOI: 10.1093/jxb/erx032] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 01/17/2017] [Indexed: 05/18/2023]
Abstract
Oscillations in pollen tubes have been reported for many cellular processes, including growth, extracellular ion fluxes, and cytosolic ion concentrations. However, there is a shortage of quantitative methods to measure and characterize the different dynamic regimes observed. Herein, a suite of open-source computational methods and original algorithms were integrated into an automated analysis pipeline that we employed to characterize specific oscillatory signatures in pollen tubes of Arabidopsis thaliana (Col-0). Importantly, it enabled us to detect and quantify a Ca2+ spiking behaviour upon growth arrest and synchronized oscillations involving growth, extracellular H+ fluxes, and cytosolic Ca2+, providing the basis for novel hypotheses. Our computational approach includes a new tip detection method with subpixel resolution using linear regression, showing improved ability to detect oscillations when compared to currently available methods. We named this data analysis pipeline 'Computational Heuristics for Understanding Kymographs and aNalysis of Oscillations Relying on Regression and Improved Statistics', or CHUKNORRIS. It can integrate diverse data types (imaging, electrophysiology), extract quantitative and time-explicit estimates of oscillatory characteristics from isolated time series (period and amplitude) or pairs (phase relationships and delays), and evaluate their synchronization state. Here, its performance is tested with ratiometric and single channel kymographs, ion flux data, and growth rate analysis.
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Affiliation(s)
- Daniel S C Damineli
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Maria Teresa Portes
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - José A Feijó
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
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22
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Michard E, Simon AA, Tavares B, Wudick MM, Feijó JA. Signaling with Ions: The Keystone for Apical Cell Growth and Morphogenesis in Pollen Tubes. PLANT PHYSIOLOGY 2017; 173:91-111. [PMID: 27895207 PMCID: PMC5210754 DOI: 10.1104/pp.16.01561] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 11/19/2016] [Indexed: 05/18/2023]
Abstract
Ion homeostasis and signaling are crucial to regulate pollen tube growth and morphogenesis and affect upstream membrane transporters and downstream targets.
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Affiliation(s)
- Erwan Michard
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815 (E.M., A.A.S., M.M.W., J.A.F.); and
- Instituto Gulbenkian de Ciência, Oeiras 2780-901, Portugal (B.T.)
| | - Alexander A Simon
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815 (E.M., A.A.S., M.M.W., J.A.F.); and
- Instituto Gulbenkian de Ciência, Oeiras 2780-901, Portugal (B.T.)
| | - Bárbara Tavares
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815 (E.M., A.A.S., M.M.W., J.A.F.); and
- Instituto Gulbenkian de Ciência, Oeiras 2780-901, Portugal (B.T.)
| | - Michael M Wudick
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815 (E.M., A.A.S., M.M.W., J.A.F.); and
- Instituto Gulbenkian de Ciência, Oeiras 2780-901, Portugal (B.T.)
| | - José A Feijó
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815 (E.M., A.A.S., M.M.W., J.A.F.); and
- Instituto Gulbenkian de Ciência, Oeiras 2780-901, Portugal (B.T.)
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23
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Mangano S, Juárez SPD, Estevez JM. ROS Regulation of Polar Growth in Plant Cells. PLANT PHYSIOLOGY 2016; 171:1593-605. [PMID: 27208283 PMCID: PMC4936551 DOI: 10.1104/pp.16.00191] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 05/04/2016] [Indexed: 05/13/2023]
Abstract
Root hair cells and pollen tubes, like fungal hyphae, possess a typical tip or polar cell expansion with growth limited to the apical dome. Cell expansion needs to be carefully regulated to produce a correct shape and size. Polar cell growth is sustained by oscillatory feedback loops comprising three main components that together play an important role regulating this process. One of the main components are reactive oxygen species (ROS) that, together with calcium ions (Ca(2+)) and pH, sustain polar growth over time. Apoplastic ROS homeostasis controlled by NADPH oxidases as well as by secreted type III peroxidases has a great impact on cell wall properties during cell expansion. Polar growth needs to balance a focused secretion of new materials in an extending but still rigid cell wall in order to contain turgor pressure. In this review, we discuss the gaps in our understanding of how ROS impact on the oscillatory Ca(2+) and pH signatures that, coordinately, allow root hair cells and pollen tubes to expand in a controlled manner to several hundred times their original size toward specific signals.
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Affiliation(s)
- Silvina Mangano
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Buenos Aires CP C1405BWE, Argentina
| | - Silvina Paola Denita Juárez
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Buenos Aires CP C1405BWE, Argentina
| | - José M Estevez
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Buenos Aires CP C1405BWE, Argentina
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24
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Cyclic nucleotide-gated channel 18 is an essential Ca2+ channel in pollen tube tips for pollen tube guidance to ovules in Arabidopsis. Proc Natl Acad Sci U S A 2016; 113:3096-101. [PMID: 26929345 DOI: 10.1073/pnas.1524629113] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In flowering plants, pollen tubes are guided into ovules by multiple attractants from female gametophytes to release paired sperm cells for double fertilization. It has been well-established that Ca(2+) gradients in the pollen tube tips are essential for pollen tube guidance and that plasma membrane Ca(2+) channels in pollen tube tips are core components that regulate Ca(2+) gradients by mediating and regulating external Ca(2+) influx. Therefore, Ca(2+) channels are the core components for pollen tube guidance. However, there is still no genetic evidence for the identification of the putative Ca(2+) channels essential for pollen tube guidance. Here, we report that the point mutations R491Q or R578K in cyclic nucleotide-gated channel 18 (CNGC18) resulted in abnormal Ca(2+) gradients and strong pollen tube guidance defects by impairing the activation of CNGC18 in Arabidopsis. The pollen tube guidance defects of cngc18-17 (R491Q) and of the transfer DNA (T-DNA) insertion mutant cngc18-1 (+/-) were completely rescued by CNGC18. Furthermore, domain-swapping experiments showed that CNGC18's transmembrane domains are indispensable for pollen tube guidance. Additionally, we found that, among eight Ca(2+) channels (including six CNGCs and two glutamate receptor-like channels), CNGC18 was the only one essential for pollen tube guidance. Thus, CNGC18 is the long-sought essential Ca(2+) channel for pollen tube guidance in Arabidopsis.
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25
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An Y, Li J, Duan C, Liu L, Sun Y, Cao R, Wang L. 5-Aminolevulinic Acid Thins Pear Fruits by Inhibiting Pollen Tube Growth via Ca(2+)-ATPase-Mediated Ca(2+) Efflux. FRONTIERS IN PLANT SCIENCE 2016; 7:121. [PMID: 26904082 PMCID: PMC4746310 DOI: 10.3389/fpls.2016.00121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 01/22/2016] [Indexed: 05/08/2023]
Abstract
Chemical fruit thinning has become a popular practice in modern fruit orchards for achieving high quality fruits, reducing costs of hand thinning and promoting return bloom. However, most of the suggested chemical thinners are often concerned for their detrimental effects and environmental problems. 5-Aminolevulic acid (ALA) is a natural, nontoxic, biodegradable, and environment-friendly plant growth regulator. One of its outstanding roles is improving plant photosynthesis and fruit quality. Here, results showed that applying 100-200 mg/L ALA at full bloom stage significantly reduced pear fruit set. Both in vivo and in vitro studies showed that ALA significantly inhibited pollen germination and tube growth. ALA decreased not only cytosolic Ca(2+) concentration ([Ca(2+)]cyt) but also "tip-focused" [Ca(2+)]cyt gradient, indicating that ALA inhibited pollen tube growth by down-regulating calcium signaling. ALA drastically enhanced pollen Ca(2+)-ATPase activity, suggesting that ALA-induced decrease of calcium signaling probably resulted from activating calcium pump. The significant negative correlations between Ca(2+)-ATPase activity and pollen germination or pollen tube length further demonstrated the critical role of calcium pump in ALA's negative effect on pollen germination. Taken together, our results suggest that ALA at low concentrations is a potential biochemical thinner, and it inhibits pollen germination and tube growth via Ca(2+) efflux by activating Ca(2+)-ATPase, thereby thinning fruits by preventing fertilization.
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Affiliation(s)
- Yuyan An
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Jie Li
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Chunhui Duan
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Longbo Liu
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Yongping Sun
- Nanjing Institute of Agricultural SciencesNanjing, China
| | - Rongxiang Cao
- Nanjing Institute of Agricultural SciencesNanjing, China
| | - Liangju Wang
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
- *Correspondence: Liangju Wang
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26
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Wang H, Han S, Siao W, Song C, Xiang Y, Wu X, Cheng P, Li H, Jásik J, Mičieta K, Turňa J, Voigt B, Baluška F, Liu J, Wang Y, Zhao H. Arabidopsis Synaptotagmin 2 Participates in Pollen Germination and Tube Growth and Is Delivered to Plasma Membrane via Conventional Secretion. MOLECULAR PLANT 2015; 8:1737-50. [PMID: 26384245 DOI: 10.1016/j.molp.2015.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 08/18/2015] [Accepted: 09/05/2015] [Indexed: 05/15/2023]
Abstract
Arabidopsis synaptotagmin 2 (SYT2) has been reported to participate in an unconventional secretory pathway in somatic cells. Our results showed that SYT2 was expressed mainly in the pollen of Arabidopsis thaliana. The pollen of syt2 T-DNA and RNA interference mutant lines exhibited reduced total germination and impeded pollen tube growth. Analysis of the expression of SYT2-GFP fusion protein in the pollen tube indicates that SYT2 was localized to distinct, patchy compartments but could co-localize with the Golgi markers, BODIPY TR C5 ceramide and GmMan1-mCherry. However, SYT2-DsRed-E5 was localized to the plasma membrane in Arabidopsis suspension cells, in addition to the Golgi apparatus. The localization of SYT2 at the plasma membrane was further supported by immunofluorescence staining in pollen tubes. Moreover, brefeldin A treatment inhibited the transport of SYT2 to the plasma membrane and caused SYT2 to aggregate and form enlarged compartments. Truncation of the SYT2-C2AB domains also resulted in retention of SYT2 in the Golgi apparatus. An in vitro phospholipid-binding assay showed that SYT2-C2AB domains bind to the phospholipid membrane in a calcium-dependent manner. Take together, our results indicated that SYT2 was required for pollen germination and pollen tube growth, and was involved in conventional exocytosis.
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Affiliation(s)
- Hui Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Shengcheng Han
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Wei Siao
- Department of Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Chunqing Song
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Yun Xiang
- School of Life Science, Lanzhou University, Lanzhou 730000, China
| | - Xiaorong Wu
- School of Life Science, Lanzhou University, Lanzhou 730000, China
| | - Pengyu Cheng
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Hongjuan Li
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Ján Jásik
- Comenius University Science Park, Comenius University, Bratislava, Mlynská dolina, 842 15 Bratislava 4, Slovakia
| | - Karol Mičieta
- Department of Botany, Faculty of Natural Sciences, Comenius University, Révová 39, 811 02 Bratislava 1, Slovakia
| | - Ján Turňa
- Department of Molecular Biology, Comenius University, Faculty of Natural Sciences, Mlynská dolina, pavilion B-2, 842 15 Bratislava 4, Slovakia
| | - Boris Voigt
- Department of Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - František Baluška
- Department of Plant Cell Biology, IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany; Institute of Botany, Slovak Academy of Sciences, Dubravska cesta 9, SK-84523 Bratislava, Slovak Republic.
| | - Jin Liu
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Yingdian Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Heping Zhao
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Science, Beijing Normal University, Beijing 100875, China.
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Wang SS, Diao WZ, Yang X, Qiao Z, Wang M, Acharya BR, Zhang W. Arabidopsis thaliana CML25 mediates the Ca(2+) regulation of K(+) transmembrane trafficking during pollen germination and tube elongation. PLANT, CELL & ENVIRONMENT 2015; 38:2372-86. [PMID: 25923414 DOI: 10.1111/pce.12559] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 04/09/2015] [Indexed: 05/10/2023]
Abstract
The concentration alteration of cytosolic-free calcium ([Ca(2+) ]cyt ) is a well-known secondary messenger in plants and plays important roles during pollen grain germination and tube elongation. Here we demonstrate that CML25, a member of calmodulin-like proteins, has Ca(2+) -binding activity and plays a role in pollen grain germination, tube elongation and seed setting. CML25 transcript was abundant in mature pollen grains and pollen tubes, and its product CML25 protein was primarily directed to the cytoplasm. Two independent CML25 loss-of-function T-DNA insertion mutants suffered a major reduction in both the rate of pollen germination and the elongation of the pollen tube. Also, pollen grains of cml25 mutants were less sensitive to the external K(+) and Ca(2+) concentration than wild-type pollen. The disruption of CML25 increased the [Ca(2+) ]cyt in both the pollen grain and the pollen tube, which in turn impaired the Ca(2+) -dependent inhibition of whole-cell inward K(+) currents in protoplasts prepared from these materials (pollen grain and pollen tube). Complementation of cml25-1 mutant resulted in the recovery of wild-type phenotype. Our findings indicate that CML25 is an important transducer in the Ca(2+) -mediated regulation of K(+) influx during pollen germination and tube elongation.
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Affiliation(s)
- Shuang-Shuang Wang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, China
| | - Wen-Zhu Diao
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, China
| | - Xue Yang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, China
- College of Technological Gardening, Shandong Yingcai University, Jinan, 250104, China
| | - Zhu Qiao
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, China
| | - Mei Wang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, China
| | - Biswa R Acharya
- Department of Biology, Pennsylvania State University University Park, State College, PA, 16802, USA
| | - Wei Zhang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, China
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Zhou L, Lan W, Chen B, Fang W, Luan S. A calcium sensor-regulated protein kinase, CALCINEURIN B-LIKE PROTEIN-INTERACTING PROTEIN KINASE19, is required for pollen tube growth and polarity. PLANT PHYSIOLOGY 2015; 167:1351-60. [PMID: 25713341 PMCID: PMC4378171 DOI: 10.1104/pp.114.256065] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/17/2015] [Indexed: 05/17/2023]
Abstract
Calcium plays an essential role in pollen tube tip growth. However, little is known concerning the molecular basis of the signaling pathways involved. Here, we identified Arabidopsis (Arabidopsis thaliana) CALCINEURIN B-LIKE PROTEIN-INTERACTING PROTEIN KINASE19 (CIPK19) as an important element to pollen tube growth through a functional survey for CIPK family members. The CIPK19 gene was specifically expressed in pollen grains and pollen tubes, and its overexpression induced severe loss of polarity in pollen tube growth. In the CIPK19 loss-of-function mutant, tube growth and polarity were significantly impaired, as demonstrated by both in vitro and in vivo pollen tube growth assays. Genetic analysis indicated that disruption of CIPK19 resulted in a male-specific transmission defect. Furthermore, loss of polarity induced by CIPK19 overexpression was associated with elevated cytosolic Ca2+ throughout the bulging tip, whereas LaCl3, a Ca2+ influx blocker, rescued CIPK19 overexpression-induced growth inhibition. Our results suggest that CIPK19 may be involved in maintaining Ca2+ homeostasis through its potential function in the modulation of Ca2+ influx.
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Affiliation(s)
- Liming Zhou
- College of Life Sciences, Fujian Agriculture and Forestry University, Fujian, Fuzhou 350002, China (L.Z., W.F.);Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing 210093, China (W.L., S.L.);College of Biological Sciences, China Agricultural University, Beijing 100193, China (B.C.); andDepartment of Plant and Microbial Biology, University of California, Berkeley, California 94720 (S.L.)
| | - Wenzhi Lan
- College of Life Sciences, Fujian Agriculture and Forestry University, Fujian, Fuzhou 350002, China (L.Z., W.F.);Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing 210093, China (W.L., S.L.);College of Biological Sciences, China Agricultural University, Beijing 100193, China (B.C.); andDepartment of Plant and Microbial Biology, University of California, Berkeley, California 94720 (S.L.)
| | - Binqing Chen
- College of Life Sciences, Fujian Agriculture and Forestry University, Fujian, Fuzhou 350002, China (L.Z., W.F.);Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing 210093, China (W.L., S.L.);College of Biological Sciences, China Agricultural University, Beijing 100193, China (B.C.); andDepartment of Plant and Microbial Biology, University of California, Berkeley, California 94720 (S.L.)
| | - Wei Fang
- College of Life Sciences, Fujian Agriculture and Forestry University, Fujian, Fuzhou 350002, China (L.Z., W.F.);Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing 210093, China (W.L., S.L.);College of Biological Sciences, China Agricultural University, Beijing 100193, China (B.C.); andDepartment of Plant and Microbial Biology, University of California, Berkeley, California 94720 (S.L.)
| | - Sheng Luan
- College of Life Sciences, Fujian Agriculture and Forestry University, Fujian, Fuzhou 350002, China (L.Z., W.F.);Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, School of Life Sciences, Nanjing University, Nanjing 210093, China (W.L., S.L.);College of Biological Sciences, China Agricultural University, Beijing 100193, China (B.C.); andDepartment of Plant and Microbial Biology, University of California, Berkeley, California 94720 (S.L.)
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Chen J, Gutjahr C, Bleckmann A, Dresselhaus T. Calcium signaling during reproduction and biotrophic fungal interactions in plants. MOLECULAR PLANT 2015; 8:595-611. [PMID: 25660409 DOI: 10.1016/j.molp.2015.01.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/18/2015] [Accepted: 01/20/2015] [Indexed: 05/25/2023]
Abstract
Many recent studies have indicated that cellular communications during plant reproduction, fungal invasion, and defense involve identical or similar molecular players and mechanisms. Indeed, pollen tube invasion and sperm release shares many common features with infection of plant tissue by fungi and oomycetes, as a tip-growing intruder needs to communicate with the receptive cells to gain access into a cell and tissue. Depending on the compatibility between cells, interactions may result in defense, invasion, growth support, or cell death. Plant cells stimulated by both pollen tubes and fungal hyphae secrete, for example, small cysteine-rich proteins and receptor-like kinases are activated leading to intracellular signaling events such as the production of reactive oxygen species (ROS) and the generation of calcium (Ca(2+)) transients. The ubiquitous and versatile second messenger Ca(2+) thereafter plays a central and crucial role in modulating numerous downstream signaling processes. In stimulated cells, it elicits both fast and slow cellular responses depending on the shape, frequency, amplitude, and duration of the Ca(2+) transients. The various Ca(2+) signatures are transduced into cellular information via a battery of Ca(2+)-binding proteins. In this review, we focus on Ca(2+) signaling and discuss its occurrence during plant reproduction and interactions of plant cells with biotrophic filamentous microbes. The participation of Ca(2+) in ROS signaling pathways is also discussed.
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Affiliation(s)
- Junyi Chen
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Caroline Gutjahr
- Faculty of Biology Genetics, Biocenter Martinsried, University of Munich (LMU), Grosshaderner Strasse 2-4, D-82152 Martinsried, Germany
| | - Andrea Bleckmann
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
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30
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Qu X, Jiang Y, Chang M, Liu X, Zhang R, Huang S. Organization and regulation of the actin cytoskeleton in the pollen tube. FRONTIERS IN PLANT SCIENCE 2015; 5:786. [PMID: 25620974 PMCID: PMC4287052 DOI: 10.3389/fpls.2014.00786] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/17/2014] [Indexed: 05/18/2023]
Abstract
Proper organization of the actin cytoskeleton is crucial for pollen tube growth. However, the precise mechanisms by which the actin cytoskeleton regulates pollen tube growth remain to be further elucidated. The functions of the actin cytoskeleton are dictated by its spatial organization and dynamics. However, early observations of the distribution of actin filaments at the pollen tube apex were quite perplexing, resulting in decades of controversial debate. Fortunately, due to improvements in fixation regimens for staining actin filaments in fixed pollen tubes, as well as the adoption of appropriate markers for visualizing actin filaments in living pollen tubes, this issue has been resolved and has given rise to the consensus view of the spatial distribution of actin filaments throughout the entire pollen tube. Importantly, recent descriptions of the dynamics of individual actin filaments in the apical region have expanded our understanding of the function of actin in regulation of pollen tube growth. Furthermore, careful documentation of the function and mode of action of several actin-binding proteins expressed in pollen have provided novel insights into the regulation of actin spatial distribution and dynamics. In the current review, we summarize our understanding of the organization, dynamics, and regulation of the actin cytoskeleton in the pollen tube.
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Affiliation(s)
- Xiaolu Qu
- Center for Plant Biology, School of Life Sciences, Tsinghua UniversityBeijing, China
| | - Yuxiang Jiang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany – Chinese Academy of SciencesBeijing, China
| | - Ming Chang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany – Chinese Academy of SciencesBeijing, China
| | - Xiaonan Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany – Chinese Academy of SciencesBeijing, China
| | - Ruihui Zhang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany – Chinese Academy of SciencesBeijing, China
| | - Shanjin Huang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany – Chinese Academy of SciencesBeijing, China
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31
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Yi J, An S, An G. OsMLO12, encoding seven transmembrane proteins, is involved with pollen hydration in rice. PLANT REPRODUCTION 2014; 27:169-80. [PMID: 25223260 DOI: 10.1007/s00497-014-0249-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 09/08/2014] [Indexed: 05/05/2023]
Abstract
Hydration is the first step in pollen germination. However, the process is not well understood. OsMLO12 is highly expressed in mature pollen grains; plants containing alleles caused by transfer DNA insertions do not produce homozygous progeny. Reciprocal crosses between wild-type and OsMLO12/osmlo12 plants showed that the mutant alleles were not transmitted through the male gametophyte. Microscopic observations revealed that, although mutant grains became mature pollen with three nuclei, they did not germinate in vitro or in vivo due to a failure in hydration. The OsMLO12 protein has seven transmembrane motifs, with an N-terminal extracellular region and a C-terminal cytosolic region. We demonstrated that the C-terminal region mediates a calcium-dependent interaction with calmodulin. Our findings suggest that pollen hydration is regulated by MLO12, possibly through an interaction with calmodulin in the cytosol.
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Affiliation(s)
- Jakyung Yi
- Department of Plant Molecular Systems Biotechnology, Crop Biotech Institute, Kyung Hee University, 1732 Deogyeong-daero, Giheung, Yongin, Gyeonggi, Korea
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32
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Shin SB, Golovkin M, Reddy ASN. A pollen-specific calmodulin-binding protein, NPG1, interacts with putative pectate lyases. Sci Rep 2014; 4:5263. [PMID: 24919580 PMCID: PMC4053719 DOI: 10.1038/srep05263] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 02/17/2014] [Indexed: 12/18/2022] Open
Abstract
Previous genetic studies have revealed that a pollen-specific calmodulin-binding protein, No Pollen Germination 1 (NPG1), is required for pollen germination. However, its mode of action is unknown. Here we report direct interaction of NPG1 with pectate lyase-like proteins (PLLs). A truncated form of AtNPG1 lacking the N-terminal tetratricopeptide repeat 1 (TPR1) failed to interact with PLLs, suggesting that it is essential for NPG1 interaction with PLLs. Localization studies with AtNPG1 fused to a fluorescent reporter driven by its native promoter revealed its presence in the cytosol and cell wall of the pollen grain and the growing pollen tube of plasmolyzed pollen. Together, our data suggest that the function of NPG1 in regulating pollen germination is mediated through its interaction with PLLs, which may modify the pollen cell wall and regulate pollen tube emergence and growth.
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Affiliation(s)
- Sung-Bong Shin
- Department of Biology, Program in Molecular Plant Biology, Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- Current Address: United States Department of Agriculture – Tree Fruit Research Laboratory, Wenatchee, WA 98801, USA
| | - Maxim Golovkin
- Department of Biology, Program in Molecular Plant Biology, Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- Current Address: Foundation for Advancement of Science, Technology and Research, Biotechnology Center, PA 18902, USA
| | - Anireddy S. N. Reddy
- Department of Biology, Program in Molecular Plant Biology, Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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33
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Lang V, Pertl-Obermeyer H, Safiarian MJ, Obermeyer G. Pump up the volume - a central role for the plasma membrane H(+) pump in pollen germination and tube growth. PROTOPLASMA 2014; 251:477-88. [PMID: 24097309 DOI: 10.1007/s00709-013-0555-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/19/2013] [Indexed: 05/10/2023]
Abstract
The plasma membrane H(+) ATPase is a member of the P-ATPase family transporting H(+) from the cytosol to the extracellular space and thus energizing the plasma membrane for the uptake of ions and nutrients. As a housekeeping gene, this protein can be detected in almost every plant cell including the exclusive expression of specific isoforms in pollen grains and tubes where its activity is a prerequisite for successful germination and growth of pollen tubes. This review summarizes the current knowledge on pollen PM H(+) ATPases and hypothesizes a central role for pollen-specific isoforms of this protein in tube growth. External as well as cytosolic signals from signal transduction and metabolic pathways are integrated by the PM H(+) ATPase and directly translated to tube growth rates, allocating the PM H(+) ATPase to an essential node in the signalling network of pollen tubes in their race to the ovule.
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Affiliation(s)
- Veronika Lang
- Molecular Plant Biophysics and Biochemistry, Department of Molecular Biology, University of Salzburg, Billrothstr. 11, 5020, Salzburg, Austria
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34
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Lassig R, Gutermuth T, Bey TD, Konrad KR, Romeis T. Pollen tube NAD(P)H oxidases act as a speed control to dampen growth rate oscillations during polarized cell growth. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 78:94-106. [PMID: 24506280 DOI: 10.1111/tpj.12452] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 01/14/2014] [Accepted: 01/17/2014] [Indexed: 05/03/2023]
Abstract
Reactive oxygen species (ROS) produced by NAD(P)H oxidases play a central role in plant stress responses and development. To better understand the function of NAD(P)H oxidases in plant development, we characterized the Arabidopsis thaliana NAD(P)H oxidases RBOHH and RBOHJ. Both proteins were specifically expressed in pollen and dynamically targeted to distinct and overlapping plasma membrane domains at the pollen tube tip. Functional loss of RBOHH and RBOHJ in homozygous double mutants resulted in reduced fertility. Analyses of pollen tube growth revealed remarkable differences in growth dynamics between Col-0 and rbohh-1 rbohj-2 pollen tubes. Growth rate oscillations of rbohh-1 rbohj-2 pollen tubes showed strong fluctuations in amplitude and frequency, ultimately leading to pollen tube collapse. Prior to disintegration, rbohh-1 rbohj-2 pollen tubes exhibit high-frequency growth oscillations, with significantly elevated growth rates, suggesting that an increase in the rate of cell-wall exocytosis precedes pollen tube collapse. Time-lapse imaging of exocytic dynamics revealed that NAD(P)H oxidases slow down pollen tube growth to coordinate the rate of cell expansion with the rate of exocytosis, thereby dampening the amplitude of intrinsic growth oscillations. Using the Ca(2+) reporter Yellow Cameleon 3.6, we demonstrate that high-amplitude growth rate oscillations in rbohh-1 rbohj-2 pollen tubes are correlated with growth-dependent Ca(2+) bursts. Electrophysiological experiments involving double mutant pollen tubes and pharmacological treatments also showed that ROS influence K(+) homeostasis. Our results indicate that, by limiting pollen tube growth, ROS produced by NAD(P)H oxidases modulate the amplitude and frequency of pollen tube growth rate oscillations.
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Affiliation(s)
- Roman Lassig
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, Königin Luise Straße 12-16, 14195, Berlin, Germany
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35
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Calcium imaging perspectives in plants. Int J Mol Sci 2014; 15:3842-59. [PMID: 24599077 PMCID: PMC3975371 DOI: 10.3390/ijms15033842] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/18/2014] [Accepted: 02/20/2014] [Indexed: 11/26/2022] Open
Abstract
The calcium ion (Ca2+) is a versatile intracellular messenger. It provides dynamic regulation of a vast array of gene transcriptions, protein kinases, transcription factors and other complex downstream signaling cascades. For the past six decades, intracellular Ca2+ concentration has been significantly studied and still many studies are under way. Our understanding of Ca2+ signaling and the corresponding physiological phenomenon is growing exponentially. Here we focus on the improvements made in the development of probes used for Ca2+ imaging and expanding the application of Ca2+ imaging in plant science research.
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36
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37
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Baluška F, Volkmann D, Hauskrecht M, Barlow PW. Root Cap Mucilage and Extracellular Calcium as Modulators of Cellular Growth in Postmitotic Growth Zones of the Maize Root Apex*. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1996.tb00866.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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Zhou L, Lan W, Jiang Y, Fang W, Luan S. A calcium-dependent protein kinase interacts with and activates a calcium channel to regulate pollen tube growth. MOLECULAR PLANT 2014; 7:369-76. [PMID: 24121288 DOI: 10.1093/mp/sst125] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Calcium, as a ubiquitous second messenger, plays essential roles in tip-growing cells, such as animal neurons, plant pollen tubes, and root hairs. However, little is known concerning the regulatory mechanisms that code and decode Ca(2+) signals in plants. The evidence presented here indicates that a calcium-dependent protein kinase, CPK32, controls polar growth of pollen tubes. Overexpression of CPK32 disrupted the polar growth along with excessive Ca(2+) accumulation in the tip. A search of downstream effector molecules for CPK32 led to identification of a cyclic nucleotide-gated channel, CNGC18, as an interacting partner for CPK32. Co-expression of CPK32 and CNGC18 resulted in activation of CNGC18 in Xenopus oocytes where expression of CNGC18 alone did not exhibit significant calcium channel activity. Overexpression of CNGC18 produced a growth arrest phenotype coupled with accumulation of calcium in the tip, similar to that induced by CPK32 overexpression. Co-expression of CPK32 and CNGC18 had a synergistic effect leading to more severe depolarization of pollen tube growth. These results provide a potential feed-forward mechanism in which calcium-activated CPK32 activates CNGC18, further promoting calcium entry during the elevation phase of Ca(2+) oscillations in the polar growth of pollen tubes.
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Affiliation(s)
- Liming Zhou
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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39
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Iwano M, Igarashi M, Tarutani Y, Kaothien-Nakayama P, Nakayama H, Moriyama H, Yakabe R, Entani T, Shimosato-Asano H, Ueki M, Tamiya G, Takayama S. A pollen coat-inducible autoinhibited Ca2+-ATPase expressed in stigmatic papilla cells is required for compatible pollination in the Brassicaceae. THE PLANT CELL 2014; 26:636-49. [PMID: 24569769 PMCID: PMC3967030 DOI: 10.1105/tpc.113.121350] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In the Brassicaceae, intraspecific non-self pollen (compatible pollen) can germinate and grow into stigmatic papilla cells, while self-pollen or interspecific pollen is rejected at this stage. However, the mechanisms underlying this selective acceptance of compatible pollen remain unclear. Here, using a cell-impermeant calcium indicator, we showed that the compatible pollen coat contains signaling molecules that stimulate Ca(2+) export from the papilla cells. Transcriptome analyses of stigmas suggested that autoinhibited Ca(2+)-ATPase13 (ACA13) was induced after both compatible pollination and compatible pollen coat treatment. A complementation test using a yeast Saccharomyces cerevisiae strain lacking major Ca(2+) transport systems suggested that ACA13 indeed functions as an autoinhibited Ca(2+) transporter. ACA13 transcription increased in papilla cells and in transmitting tracts after pollination. ACA13 protein localized to the plasma membrane and to vesicles near the Golgi body and accumulated at the pollen tube penetration site after pollination. The stigma of a T-DNA insertion line of ACA13 exhibited reduced Ca(2+) export, as well as defects in compatible pollen germination and seed production. These findings suggest that stigmatic ACA13 functions in the export of Ca(2+) to the compatible pollen tube, which promotes successful fertilization.
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Affiliation(s)
- Megumi Iwano
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
- Address correspondence to
| | - Motoko Igarashi
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Yoshiaki Tarutani
- Division of Agricultural Genetics, Department of Integrated Genetics, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Pulla Kaothien-Nakayama
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Hideki Nakayama
- Instutute of Environmental Studies, Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan
| | - Hideki Moriyama
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Ryo Yakabe
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Tetsuyuki Entani
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Hiroko Shimosato-Asano
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Masao Ueki
- Tohoku Medical Megabank Organization, Graduate School of Medicine, Tohoku University, Sendai 980-8573, Japan
| | - Gen Tamiya
- Tohoku Medical Megabank Organization, Graduate School of Medicine, Tohoku University, Sendai 980-8573, Japan
| | - Seiji Takayama
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
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40
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DERKSEN JAN, RUTTEN TWAN, VAN AMSTEL TON, DE WIN ANNA, DORIS FIONA, STEER MARTIN. Regulation of pollen tube growth. ACTA ACUST UNITED AC 2013. [DOI: 10.1111/j.1438-8677.1995.tb00773.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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41
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Nezhad AS, Packirisamy M, Bhat R, Geitmann A. In Vitro Study of Oscillatory Growth Dynamics of Camellia Pollen Tubes in Microfluidic Environment. IEEE Trans Biomed Eng 2013; 60:3185-93. [DOI: 10.1109/tbme.2013.2270914] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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42
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Gutermuth T, Lassig R, Portes MT, Maierhofer T, Romeis T, Borst JW, Hedrich R, Feijó JA, Konrad KR. Pollen tube growth regulation by free anions depends on the interaction between the anion channel SLAH3 and calcium-dependent protein kinases CPK2 and CPK20. THE PLANT CELL 2013; 25:4525-43. [PMID: 24280384 PMCID: PMC3875734 DOI: 10.1105/tpc.113.118463] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 10/17/2013] [Accepted: 10/31/2013] [Indexed: 05/18/2023]
Abstract
Apical growth in pollen tubes (PTs) is associated with the presence of tip-focused ion gradients and fluxes, implying polar localization or regulation of the underlying transporters. The molecular identity and regulation of anion transporters in PTs is unknown. Here we report a negative gradient of cytosolic anion concentration focused on the tip, in negative correlation with the cytosolic Ca(2+) concentration. We hypothesized that a possible link between these two ions is based on the presence of Ca(2+)-dependent protein kinases (CPKs). We characterized anion channels and CPK transcripts in PTs and analyzed their localization. Yellow fluorescent protein (YFP) tagging of a homolog of SLOW ANION CHANNEL-ASSOCIATED1 (SLAH3:YFP) was widespread along PTs, but, in accordance with the anion efflux, CPK2/CPK20/CPK17/CPK34:YFP fluorescence was strictly localized at the tip plasma membrane. Expression of SLAH3 with either CPK2 or CPK20 (but not CPK17/CPK34) in Xenopus laevis oocytes elicited S-type anion channel currents. Interaction of SLAH3 with CPK2/CPK20 (but not CPK17/CPK34) was confirmed by Förster-resonance energy transfer fluorescence lifetime microscopy in Arabidopsis thaliana mesophyll protoplasts and bimolecular fluorescence complementation in living PTs. Compared with wild-type PTs, slah3-1 and slah3-2 as well as cpk2-1 cpk20-2 PTs had reduced anion currents. Double mutant cpk2-1 cpk20-2 and slah3-1 PTs had reduced extracellular anion fluxes at the tip. Our studies provide evidence for a Ca(2+)-dependent CPK2/CPK20 regulation of the anion channel SLAH3 to regulate PT growth.
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Affiliation(s)
- Timo Gutermuth
- Gulbenkian Institute of Science, P-2780-156 Oeiras, Portugal
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082 Wuerzburg, Germany
| | - Roman Lassig
- Department of Plant Biochemistry, Dahlem Centre of Plant Sciences, Free University of Berlin, 14195 Berlin, Germany
| | | | - Tobias Maierhofer
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082 Wuerzburg, Germany
| | - Tina Romeis
- Department of Plant Biochemistry, Dahlem Centre of Plant Sciences, Free University of Berlin, 14195 Berlin, Germany
| | - Jan-Willem Borst
- Laboratory of Biochemistry and Microspectroscopy Centre, Wageningen University, 6708 Wageningen, The Netherlands
| | - Rainer Hedrich
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082 Wuerzburg, Germany
| | - José A. Feijó
- Gulbenkian Institute of Science, P-2780-156 Oeiras, Portugal
- Faculty of Sciences, Department of Plant Biology, University of Lisbon, P-1749-016 Lisbon, Portugal
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815
| | - Kai R. Konrad
- Gulbenkian Institute of Science, P-2780-156 Oeiras, Portugal
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, 97082 Wuerzburg, Germany
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43
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Chen DH, Acharya BR, Liu W, Zhang W. Interaction between Calcium and Actin in Guard Cell and Pollen Signaling Networks. PLANTS (BASEL, SWITZERLAND) 2013; 2:615-34. [PMID: 27137395 PMCID: PMC4844389 DOI: 10.3390/plants2040615] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 09/25/2013] [Accepted: 09/26/2013] [Indexed: 12/17/2022]
Abstract
Calcium (Ca(2+)) plays important roles in plant growth, development, and signal transduction. It is a vital nutrient for plant physical design, such as cell wall and membrane, and also serves as a counter-cation for biochemical, inorganic, and organic anions, and more particularly, its concentration change in cytosol is a ubiquitous second messenger in plant physiological signaling in responses to developmental and environmental stimuli. Actin cytoskeleton is well known for its importance in cellular architecture maintenance and its significance in cytoplasmic streaming and cell division. In plant cell system, the actin dynamics is a process of polymerization and de-polymerization of globular actin and filamentous actin and that acts as an active regulator for calcium signaling by controlling calcium evoked physiological responses. The elucidation of the interaction between calcium and actin dynamics will be helpful for further investigation of plant cell signaling networks at molecular level. This review mainly focuses on the recent advances in understanding the interaction between the two aforementioned signaling components in two well-established model systems of plant, guard cell, and pollen.
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Affiliation(s)
- Dong-Hua Chen
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
| | - Biswa R Acharya
- Biology Department, Penn State University, University Park, PA 16802, USA.
| | - Wei Liu
- High-Tech Research Center, Shandong Academy of Agricultural Sciences, Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan 250100, Shandong, China.
| | - Wei Zhang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
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Hao H, Chen T, Fan L, Li R, Wang X. 2, 6-Dichlorobenzonitrile causes multiple effects on pollen tube growth beyond altering cellulose synthesis in Pinus bungeana Zucc. PLoS One 2013; 8:e76660. [PMID: 24146903 PMCID: PMC3795706 DOI: 10.1371/journal.pone.0076660] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 08/26/2013] [Indexed: 01/14/2023] Open
Abstract
Cellulose is an important component of cell wall, yet its location and function in pollen tubes remain speculative. In this paper, we studied the role of cellulose synthesis in pollen tube elongation in Pinus bungeana Zucc. by using the specific inhibitor, 2, 6-dichlorobenzonitrile (DCB). In the presence of DCB, the growth rate and morphology of pollen tubes were distinctly changed. The organization of cytoskeleton and vesicle trafficking were also disturbed. Ultrastructure of pollen tubes treated with DCB was characterized by the loose tube wall and damaged organelles. DCB treatment induced distinct changes in tube wall components. Fluorescence labeling results showed that callose, and acidic pectin accumulated in the tip regions, whereas there was less cellulose when treated with DCB. These results were confirmed by FTIR microspectroscopic analysis. In summary, our findings showed that inhibition of cellulose synthesis by DCB affected the organization of cytoskeleton and vesicle trafficking in pollen tubes, and induced changes in the tube wall chemical composition in a dose-dependent manner. These results confirm that cellulose is involved in the establishment of growth direction of pollen tubes, and plays important role in the cell wall construction during pollen tube development despite its lower quantity.
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Affiliation(s)
- Huaiqing Hao
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Tong Chen
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Lusheng Fan
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Ruili Li
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xiaohua Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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45
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Martins TV, Evans MJ, Woolfenden HC, Morris RJ. Towards the Physics of Calcium Signalling in Plants. PLANTS (BASEL, SWITZERLAND) 2013; 2:541-88. [PMID: 27137393 PMCID: PMC4844391 DOI: 10.3390/plants2040541] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 09/17/2013] [Accepted: 09/22/2013] [Indexed: 12/21/2022]
Abstract
Calcium is an abundant element with a wide variety of important roles within cells. Calcium ions are inter- and intra-cellular messengers that are involved in numerous signalling pathways. Fluctuating compartment-specific calcium ion concentrations can lead to localised and even plant-wide oscillations that can regulate downstream events. Understanding the mechanisms that give rise to these complex patterns that vary both in space and time can be challenging, even in cases for which individual components have been identified. Taking a systems biology approach, mathematical and computational techniques can be employed to produce models that recapitulate experimental observations and capture our current understanding of the system. Useful models make novel predictions that can be investigated and falsified experimentally. This review brings together recent work on the modelling of calcium signalling in plants, from the scale of ion channels through to plant-wide responses to external stimuli. Some in silico results that have informed later experiments are highlighted.
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Affiliation(s)
- Teresa Vaz Martins
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Matthew J Evans
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Hugh C Woolfenden
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Richard J Morris
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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46
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Guan Y, Guo J, Li H, Yang Z. Signaling in pollen tube growth: crosstalk, feedback, and missing links. MOLECULAR PLANT 2013; 6:1053-64. [PMID: 23873928 PMCID: PMC3842152 DOI: 10.1093/mp/sst070] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/25/2013] [Indexed: 05/19/2023]
Abstract
Pollen tubes elongate rapidly at their tips through highly polarized cell growth known as tip growth. Tip growth requires intensive exocytosis at the tip, which is supported by a dynamic cytoskeleton and vesicle trafficking. Several signaling pathways have been demonstrated to coordinate pollen tube growth by regulating cellular activities such as actin dynamics, exocytosis, and endocytosis. These signaling pathways crosstalk to form a signaling network that coordinates the cellular processes required for tip growth. The homeostasis of key signaling molecules is critical for the proper elongation of the pollen tube tip, and is commonly fine-tuned by positive and negative regulations. In addition to the major signaling pathways, emerging evidence implies the roles of other signals in the regulation of pollen tube growth. Here we review and discuss how these signaling networks modulate the rapid growth of pollen tubes.
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Affiliation(s)
- Yuefeng Guan
- Shanghai Center for Plant Stress Biology and Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
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Mähs A, Steinhorst L, Han JP, Shen LK, Wang Y, Kudla J. The calcineurin B-like Ca2+ sensors CBL1 and CBL9 function in pollen germination and pollen tube growth in Arabidopsis. MOLECULAR PLANT 2013; 6:1149-62. [PMID: 23741064 DOI: 10.1093/mp/sst095] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ca(2+) has been established as an important second messenger regulating pollen germination and tube growth. However, to date, only a few signaling components have been identified to decode and relay Ca(2+) signals in growing pollen tubes. Here, we report a function for the calcineurin B-like (CBL) Ca(2+) sensor proteins CBL1 and CBL9 from Arabidopsis in pollen germination and tube growth. Both proteins are expressed in mature pollen and pollen tubes and impair pollen tube growth and morphology if transiently overexpressed in tobacco pollen. The induction of these phenotypes requires efficient plasma membrane targeting of CBL1 and is independent of Ca(2+) binding to the fourth EF-hand of CBL1. Overexpression of CBL1 or its closest homolog CBL9 in Arabidopsis renders pollen germination and tube growth hypersensitive towards high external K(+) concentrations while disruption of CBL1 and CBL9 reduces pollen tube growth under low K(+) conditions. Together, our data identify a crucial function for CBL1 and CBL9 in pollen germination and tube growth and suggest a model in which both proteins act at the plasma membrane through regulation of K(+) homeostasis.
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Affiliation(s)
- Anette Mähs
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 4, 48149 Münster, Germany
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48
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Qu X, Zhang H, Xie Y, Wang J, Chen N, Huang S. Arabidopsis villins promote actin turnover at pollen tube tips and facilitate the construction of actin collars. THE PLANT CELL 2013; 25:1803-17. [PMID: 23715472 PMCID: PMC3694707 DOI: 10.1105/tpc.113.110940] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 04/28/2013] [Accepted: 05/12/2013] [Indexed: 05/18/2023]
Abstract
Apical actin filaments are crucial for pollen tube tip growth. However, the specific dynamic changes and regulatory mechanisms associated with actin filaments in the apical region remain largely unknown. Here, we have investigated the quantitative dynamic parameters that underlie actin filament growth and disappearance in the apical regions of pollen tubes and identified villin as the major player that drives rapid turnover of actin filaments in this region. Downregulation of Arabidopsis thaliana VILLIN2 (VLN2) and VLN5 led to accumulation of actin filaments at the pollen tube apex. Careful analysis of single filament dynamics showed that the severing frequency significantly decreased, and the lifetime significantly increased in vln2 vln5 pollen tubes. These results indicate that villin-mediated severing is critical for turnover and departure of actin filaments originating in the apical region. Consequently, the construction of actin collars was affected in vln2 vln5 pollen tubes. In addition to the decrease in severing frequency, actin filaments also became wavy and buckled in the apical cytoplasm of vln2 vln5 pollen tubes. These results suggest that villin confers rigidity upon actin filaments. Furthermore, an observed decrease in skewness of actin filaments in the subapical region of vln2 vln5 pollen tubes suggests that villin-mediated bundling activity may also play a role in the construction of actin collars. Thus, our data suggest that villins promote actin turnover at pollen tube tips and facilitate the construction of actin collars.
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Affiliation(s)
- Xiaolu Qu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Hua Zhang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yurong Xie
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Juan Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Naizhi Chen
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Shanjin Huang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- National Center for Plant Gene Research, Beijing 100101, China
- Address correspondence to
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PiSCP1 and PiCDPK2 Localize to Peroxisomes and Are Involved in Pollen Tube Growth in Petunia Inflata. PLANTS 2013; 2:72-86. [PMID: 27137367 PMCID: PMC4844289 DOI: 10.3390/plants2010072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 02/19/2013] [Accepted: 02/26/2013] [Indexed: 01/13/2023]
Abstract
Petunia inflata small CDPK-interacting protein 1 (PiSCP1) was identified as a pollen expressed PiCDPK1 interacting protein using the yeast two hybrid system and the interaction confirmed using pull-down and phosphorylation assays. PiSCP1 is pollen specific and shares amino acid homology with uncharacterized proteins from diverse species of higher plants, but no protein of known function. Expression of PiSCP1-GFP in vivo inhibited pollen tube growth and was shown to localize to peroxisomes in growing pollen tubes. As PiCDPK1 is plasma membrane localized, we investigated the localization of a second isoform, PiCDPK2, and show that it co-localizes to peroxisomes with PiSCP1 and that the two proteins interact in the yeast 2 hybrid interaction assay, suggesting that interaction with the latter CDPK isoform is likely the one of biological relevance. Both PiCDPK2 and PiSCP1 affect pollen tube growth, presumably by mediating peroxisome function, however how they do so is currently not clear.
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50
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Zhu L, Zhang Y, Kang E, Xu Q, Wang M, Rui Y, Liu B, Yuan M, Fu Y. MAP18 regulates the direction of pollen tube growth in Arabidopsis by modulating F-actin organization. THE PLANT CELL 2013; 25:851-67. [PMID: 23463774 PMCID: PMC3634693 DOI: 10.1105/tpc.113.110528] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
For fertilization to occur in plants, the pollen tube must be guided to enter the ovule via the micropyle. Previous reports have implicated actin filaments, actin binding proteins, and the tip-focused calcium gradient as key contributors to polar growth of pollen tubes; however, the regulation of directional pollen tube growth is largely unknown. We reported previously that Arabidopsis thaliana MICROTUBULE-ASSOCIATED PROTEIN18 (MAP18) contributes to directional cell growth and cortical microtubule organization. The preferential expression of MAP18 in pollen and in pollen tubes suggests that MAP18 also may function in pollen tube growth. In this study, we demonstrate that MAP18 functions in pollen tubes by influencing actin organization, rather than microtubule assembly. In vitro biochemical results indicate that MAP18 exhibits Ca(2+)-dependent filamentous (F)-actin-severing activity. Abnormal expression of MAP18 in map18 and MAP18 OX plants was associated with disorganization of the actin cytoskeleton in the tube apex, resulting in aberrant pollen tube growth patterns and morphologies, inaccurate micropyle targeting, and fewer fertilization events. Experiments with MAP18 mutants created by site-directed mutagenesis suggest that F-actin-severing activity is essential to the effects of MAP18 on pollen tube growth direction. Our study demonstrates that in Arabidopsis, MAP18 guides the direction of pollen tube growth by modulating actin filaments.
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