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Long SP, Taylor SH, Burgess SJ, Carmo-Silva E, Lawson T, De Souza AP, Leonelli L, Wang Y. Into the Shadows and Back into Sunlight: Photosynthesis in Fluctuating Light. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:617-648. [PMID: 35595290 DOI: 10.1146/annurev-arplant-070221-024745] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Photosynthesis is an important remaining opportunity for further improvement in the genetic yield potential of our major crops. Measurement, analysis, and improvement of leaf CO2 assimilation (A) have focused largely on photosynthetic rates under light-saturated steady-state conditions. However, in modern crop canopies of several leaf layers, light is rarely constant, and the majority of leaves experience marked light fluctuations throughout the day. It takes several minutes for photosynthesis to regain efficiency in both sun-shade and shade-sun transitions, costing a calculated 10-40% of potential crop CO2 assimilation. Transgenic manipulations to accelerate the adjustment in sun-shade transitions have already shown a substantial productivity increase in field trials. Here, we explore means to further accelerate these adjustments and minimize these losses through transgenic manipulation, gene editing, and exploitation of natural variation. Measurement andanalysis of photosynthesis in sun-shade and shade-sun transitions are explained. Factors limiting speeds of adjustment and how they could be modified to effect improved efficiency are reviewed, specifically nonphotochemical quenching (NPQ), Rubisco activation, and stomatal responses.
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Affiliation(s)
- Stephen P Long
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Samuel H Taylor
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Steven J Burgess
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
| | | | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Amanda P De Souza
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
| | - Lauriebeth Leonelli
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yu Wang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
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Biel A, Moser M, Groves NR, Meier I. Distinct Roles for KASH Proteins SINE1 and SINE2 in Guard Cell Actin Reorganization, Calcium Oscillations, and Vacuolar Remodeling. FRONTIERS IN PLANT SCIENCE 2022; 13:784342. [PMID: 35599883 PMCID: PMC9120628 DOI: 10.3389/fpls.2022.784342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex is a protein complex spanning the inner and outer membranes of the nuclear envelope. Outer nuclear membrane KASH proteins interact in the nuclear envelope lumen with inner nuclear membrane SUN proteins. The paralogous Arabidopsis KASH proteins SINE1 and SINE2 function during stomatal dynamics induced by light-dark transitions and ABA. Previous studies have shown F-actin organization, cytoplasmic calcium (Ca2+) oscillations, and vacuolar morphology changes are involved in ABA-induced stomatal closure. Here, we show that SINE1 and SINE2 are both required for actin pattern changes during ABA-induced stomatal closure, but influence different, temporally distinguishable steps. External Ca2+ partially overrides the mutant defects. ABA-induced cytoplasmic Ca2+ oscillations are diminished in sine2-1 but not sine1-1, and this defect can be rescued by both exogenous Ca2+ and F-actin depolymerization. We show first evidence for nuclear Ca2+ oscillations during ABA-induced stomatal closure, which are disrupted in sine2-1. Vacuolar fragmentation is impaired in both mutants and is partially rescued by F-actin depolymerization. Together, these data indicate distinct roles for SINE1 and SINE2 upstream of this network of players involved in ABA-based stomatal closure, suggesting a role for the nuclear surface in guard cell ABA signaling.
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Affiliation(s)
- Alecia Biel
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, United States
| | - Morgan Moser
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, United States
| | - Norman R. Groves
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, United States
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, United States
| | - Iris Meier
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, United States
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, United States
- Center for RNA Biology, The Ohio State University, Columbus, OH, United States
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3
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He Z, Wang Z, Nie X, Qu M, Zhao H, Ji X, Wang Y. UNFERTILIZED EMBRYO SAC 12 phosphorylation plays a crucial role in conferring salt tolerance. PLANT PHYSIOLOGY 2022; 188:1385-1401. [PMID: 34904673 PMCID: PMC8825338 DOI: 10.1093/plphys/kiab549] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/28/2021] [Indexed: 06/14/2023]
Abstract
Arabidopsis (Arabidopsis thaliana) UNFERTILIZED EMBRYO SAC 12 (AtUNE12) belongs to the basic helix-loop-helix DNA-binding superfamily of proteins. However, its function is not well known. Here, we found that AtUNE12 plays an important role in mediating salt tolerance. AtUNE12 is a transcriptional activator located in the nucleus whose expression is induced by NaCl, mannitol, and abscisic acid. In addition to binding to the G-box "CACGTG", AtUNE12 also binds to the low temperature responsive element 15 (LTRE15) "CCGAC". Furthermore, the serine residue at position 108 of AtUNE12 is phosphorylated during the salt stress response, enabling AtUNE12 to trigger gene expression by binding to G-box and/or LTRE15 motifs. Phosphorylated AtUNE12 regulates the expression of the genes involved in ion transport leading to reduced Na+ accumulation and K+ loss. At the same time, phosphorylation of AtUNE12 also induces the expression of AtMYB61 to decrease stomatal aperture, leading to a reduced transpiration rate. Overall, AtUNE12 serves as a transcriptional activator that is induced and phosphorylated upon salt stress, and the induction and phosphorylation of AtUNE12 in turn activate the salt-overly-sensitive pathway and decrease the stomatal aperture, enabling improved salt tolerance.
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Affiliation(s)
- Zihang He
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Zhibo Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Xianguang Nie
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Ming Qu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Huimin Zhao
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Xiaoyu Ji
- College of Forestry, Shenyang Agricultural University, Shenyang 110866, China
| | - Yucheng Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
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Yang Y, Zhao Y, Zheng W, Zhao Y, Zhao S, Wang Q, Bai L, Zhang T, Huang S, Song C, Yuan M, Guo Y. Phosphatidylinositol 3-phosphate regulates SCAB1-mediated F-actin reorganization during stomatal closure in Arabidopsis. THE PLANT CELL 2022; 34:477-494. [PMID: 34850207 PMCID: PMC8773959 DOI: 10.1093/plcell/koab264] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 10/22/2021] [Indexed: 05/20/2023]
Abstract
Stomatal movement is critical for plant responses to environmental changes and is regulated by the important signaling molecule phosphatidylinositol 3-phosphate (PI3P). However, the molecular mechanism underlying this process is not well understood. In this study, we show that PI3P binds to stomatal closure-related actin-binding protein1 (SCAB1), a plant-specific F-actin-binding and -bundling protein, and inhibits the oligomerization of SCAB1 to regulate its activity on F-actin in guard cells during stomatal closure in Arabidopsis thaliana. SCAB1 binds specifically to PI3P, but not to other phosphoinositides. Treatment with wortmannin, an inhibitor of phosphoinositide kinase that generates PI3P, leads to an increase of the intermolecular interaction and oligomerization of SCAB1, stabilization of F-actin, and retardation of F-actin reorganization during abscisic acid (ABA)-induced stomatal closure. When the binding activity of SCAB1 to PI3P is abolished, the mutated proteins do not rescue the stability and realignment of F-actin regulated by SCAB1 and the stomatal closure in the scab1 mutant. The expression of PI3P biosynthesis genes is consistently induced when the plants are exposed to drought and ABA treatments. Furthermore, the binding of PI3P to SCAB1 is also required for vacuolar remodeling during stomatal closure. Our results illustrate a PI3P-regulated pathway during ABA-induced stomatal closure, which involves the mediation of SCAB1 activity in F-actin reorganization.
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Affiliation(s)
| | | | | | - Yang Zhao
- Shanghai Center for Plant Stress Biology, CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Shuangshuang Zhao
- Key Life Science College, Laboratory of Plant Stress, Shandong Normal University, Jinan 250014, China
| | - Qiannan Wang
- School of Life Sciences, Center for Plant Biology, Tsinghua University, Beijing 100084, China
| | - Li Bai
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
| | - Tianren Zhang
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
| | - Shanjin Huang
- School of Life Sciences, Center for Plant Biology, Tsinghua University, Beijing 100084, China
| | - Chunpeng Song
- Collaborative Innovation Center of Crop Stress Biology, Henan Province, Institute of Plant Stress Biology, Henan University, Kaifeng 475001, China
| | - Ming Yuan
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
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Li Y, Zhang X, Zhang Y, Ren H. Controlling the Gate: The Functions of the Cytoskeleton in Stomatal Movement. FRONTIERS IN PLANT SCIENCE 2022; 13:849729. [PMID: 35283892 PMCID: PMC8905143 DOI: 10.3389/fpls.2022.849729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 01/26/2022] [Indexed: 05/03/2023]
Abstract
Stomata are specialized epidermal structures composed of two guard cells and are involved in gas and water exchange between plants and the environment and pathogen entry into the plant interior. Stomatal movement is a response to many internal and external stimuli to increase adaptability to environmental change. The cytoskeleton, including actin filaments and microtubules, is highly dynamic in guard cells during stomatal movement, and the destruction of the cytoskeleton interferes with stomatal movement. In this review, we discuss recent progress on the organization and dynamics of actin filaments and microtubule network in guard cells, and we pay special attention to cytoskeletal-associated protein-mediated cytoskeletal rearrangements during stomatal movement. We also discuss the potential mechanisms of stomatal movement in relation to the cytoskeleton and attempt to provide a foundation for further research in this field.
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Affiliation(s)
- Yihao Li
- Center for Biological Science and Technology, Guangdong Zhuhai-Macao Joint Biotech Laboratory, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai, China
| | - Xin Zhang
- Center for Biological Science and Technology, Guangdong Zhuhai-Macao Joint Biotech Laboratory, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai, China
| | - Yi Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
- *Correspondence: Yi Zhang,
| | - Haiyun Ren
- Center for Biological Science and Technology, Guangdong Zhuhai-Macao Joint Biotech Laboratory, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai, China
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
- Haiyun Ren,
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Yu W, Shin MR, Sesti F. Complexes formed with integrin-α5 and KCNB1 potassium channel wild type or epilepsy-susceptibility variants modulate cellular plasticity via Ras and Akt signaling. FASEB J 2019; 33:14680-14689. [PMID: 31682765 DOI: 10.1096/fj.201901792r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Voltage-gated potassium (K+) channel subfamily B member 1 (KCNB1, Kv2.1) and integrin-α5 form macromolecular complexes-named integrin-α5-KCNB1 complexes (IKCs)-in the human brain, but their function was poorly understood. Here we report that membrane depolarization triggered IKC intracellular signals mediated by small GTPases of the Ras subfamily and protein kinase B (Akt) to advance the development of filopodia and lamellipodia in Chinese hamster ovary cells, stimulate their motility, and enhance neurite outgrowth in mouse neuroblastoma Neuro2a cells. Five KCNB1 mutants (L211P, R312H G379R, G381R, and F416L) linked to severe infancy or early-onset epileptic encephalopathy exhibited markedly defective conduction. However, although L211P, G379R, and G381R normally engaged Ras/Akt and stimulated cell migration, R312H and F416L failed to activate Ras/Akt signaling and did not enhance cell migration. Taken together, these data suggest that IKCs modulate cellular plasticity via Ras and Akt signaling. As such, defective IKCs may cause epilepsy through mechanisms other than dysregulated excitability such as, for example, abnormal neuronal development and resulting synaptic connectivity.-Yu, W., Shin, M. R., Sesti, F. Complexes formed with integrin-α5 and KCNB1 potassium channel wild type or epilepsy-susceptibility variants modulate cellular plasticity via Ras and Akt signaling.
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Affiliation(s)
- Wei Yu
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Mi Ryung Shin
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Federico Sesti
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
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AP3M harbors actin filament binding activity that is crucial for vacuole morphology and stomatal closure in Arabidopsis. Proc Natl Acad Sci U S A 2019; 116:18132-18141. [PMID: 31431522 DOI: 10.1073/pnas.1901431116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Stomatal movement is essential for plant growth. This process is precisely regulated by various cellular activities in guard cells. F-actin dynamics and vacuole morphology are both involved in stomatal movement. The sorting of cargoes by clathrin adaptor protein (AP) complexes from the Golgi to the vacuole is critical for establishing a normal vacuole morphology. In this study, we demonstrate that the medium subunit of the AP3 complex (AP3M) binds to and severs actin filaments in vitro and that it participates in the sorting of cargoes (such as the sucrose exporter SUC4) to the tonoplast, and thereby regulates stomatal closure in Arabidopsis thaliana Defects in AP3 or SUC4 led to more rapid water loss and delayed stomatal closure, as well as hypersensitivity to drought stress. In ap3m mutants, the F-actin status was altered compared to the wild type, and the sorted cargoes failed to localize to the tonoplast. AP3M contains a previously unidentified F-actin binding domain that is conserved in AP3M homologs in both plants and animals. Mutations in the F-actin binding domain of AP3M abolished its F-actin binding activity in vitro, leading to an aberrant vacuole morphology and reduced levels of SUC4 on the tonoplast in guard cells. Our findings indicate that the F-actin binding activity of AP3M is required for the precise localization of AP3-dependent cargoes to the tonoplast and for the regulation of vacuole morphology in guard cells during stomatal closure.
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Li X, Diao M, Zhang Y, Chen G, Huang S, Chen N. Guard Cell Microfilament Analyzer Facilitates the Analysis of the Organization and Dynamics of Actin Filaments in Arabidopsis Guard Cells. Int J Mol Sci 2019; 20:ijms20112753. [PMID: 31195605 PMCID: PMC6600335 DOI: 10.3390/ijms20112753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/26/2019] [Accepted: 05/28/2019] [Indexed: 11/29/2022] Open
Abstract
The actin cytoskeleton is involved in regulating stomatal movement, which forms distinct actin arrays within guard cells of stomata with different apertures. How those actin arrays are formed and maintained remains largely unexplored. Elucidation of the dynamic behavior of differently oriented actin filaments in guard cells will enhance our understanding in this regard. Here, we initially developed a program called ‘guard cell microfilament analyzer’ (GCMA) that enables the selection of individual actin filaments and analysis of their orientations semiautomatically in guard cells. We next traced the dynamics of individual actin filaments and performed careful quantification in open and closed stomata. We found that de novo nucleation of actin filaments occurs at both dorsal and ventral sides of guard cells from open and closed stomata. Interestingly, most of the nucleated actin filaments elongate radially and longitudinally in open and closed stomata, respectively. Strikingly, radial filaments tend to form bundles whereas longitudinal filaments tend to be removed by severing and depolymerization in open stomata. By contrast, longitudinal filaments tend to form bundles that are severed less frequently in closed stomata. These observations provide insights into the formation and maintenance of distinct actin arrays in guard cells in stomata of different apertures.
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Affiliation(s)
- Xin Li
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Min Diao
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
- iHuman Institute, Shanghai Tech University, Shanghai 201210, China.
| | - Yanan Zhang
- OLYMPUS (CHINA) CO., LTD, Beijing 100027, China.
| | - Guanlin Chen
- Baidu Online Network Technology (Beijing) CO., LTD, Beijing 100193, China.
| | - Shanjin Huang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
| | - Naizhi Chen
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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Lawson T, Vialet-Chabrand S. Speedy stomata, photosynthesis and plant water use efficiency. THE NEW PHYTOLOGIST 2019; 221:93-98. [PMID: 29987878 DOI: 10.1111/nph.15330] [Citation(s) in RCA: 190] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/27/2018] [Indexed: 05/20/2023]
Abstract
Contents Summary 93 I. Introduction 93 II. Influence of the speed of gs responses on A and Wi 93 III. Determinants of the rapidity of gs responses 95 IV. Conclusion 97 Acknowledgements 97 References 97 SUMMARY: Stomatal movements control CO2 uptake for photosynthesis and water loss through transpiration, and therefore play a key role in plant productivity and water use efficiency. The predicted doubling of global water usage by 2030 mean that stomatal behaviour is central to current efforts to increase photosynthesis and crop yields, particularly under conditions of reduced water availability. In the field, slow stomatal responses to dynamic environmental conditions add a temporal dimension to gaseous fluxes between the leaf and atmosphere. Here, we review recent work on the rapidity of stomatal responses and present some of the possible anatomical and biochemical mechanisms that influence the rapidity of stomatal movements.
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Affiliation(s)
- Tracy Lawson
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
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10
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Yu Q, Ren JJ, Kong LJ, Wang XL. Actin filaments regulate the adhesion between the plasma membrane and the cell wall of tobacco guard cells. PROTOPLASMA 2018; 255:235-245. [PMID: 28803402 DOI: 10.1007/s00709-017-1149-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 07/24/2017] [Indexed: 06/07/2023]
Abstract
During the opening and closing of stomata, guard cells undergo rapid and reversible changes in their volume and shape, which affects the adhesion of the plasma membrane (PM) to the cell wall (CW). The dynamics of actin filaments in guard cells are involved in stomatal movement by regulating structural changes and intracellular signaling. However, it is unclear whether actin dynamics regulate the adhesion of the PM to the CW. In this study, we investigated the relationship between actin dynamics and PM-CW adhesion by the hyperosmotic-induced plasmolysis of tobacco guard cells. We found that actin filaments in guard cells were depolymerized during mannitol-induced plasmolysis. The inhibition of actin dynamics by treatment with latrunculin B or jasplakinolide and the disruption of the adhesion between the PM and the CW by treatment with RGDS peptide (Arg-Gly-Asp-Ser) enhanced guard cell plasmolysis. However, treatment with latrunculin B alleviated the RGDS peptide-induced plasmolysis and endocytosis. Our results reveal that the actin depolymerization is involved in the regulation of the PW-CW adhesion during hyperosmotic-induced plasmolysis in tobacco guard cells.
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Affiliation(s)
- Qin Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Jing-Jing Ren
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Lan-Jing Kong
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Xiu-Ling Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China.
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11
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Zhang C, Xiao Y, Ma Y, Li B, Liu Z, Lu C, Liu X, Wei Y, Zhu Z, Zhang Y. Algae biomass as a precursor for synthesis of nitrogen-and sulfur-co-doped carbon dots: A better probe in Arabidopsis guard cells and root tissues. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 174:315-322. [DOI: 10.1016/j.jphotobiol.2017.06.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Revised: 06/06/2017] [Accepted: 06/21/2017] [Indexed: 01/20/2023]
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12
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Pérez Koldenkova V, Hatsugai N. Vacuolar convolution: possible mechanisms and role of phosphatidylinositol 3,5-bisphosphate. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:751-760. [PMID: 32480604 DOI: 10.1071/fp16443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 05/19/2017] [Indexed: 06/11/2023]
Abstract
The central or lytic vacuole is the largest intracellular organelle in plant cells, but we know unacceptably little about the mechanisms regulating its function in vivo. The underlying reasons are related to difficulties in accessing this organelle without disrupting the cellular integrity and to the dynamic morphology of the vacuole, which lacks a defined structure. Among such morphological changes, vacuolar convolution is probably the most commonly observed event, reflected in the (reversible) transformation of a large central vacuole into a structure consisting of interconnected bubbles of a smaller size. Such behaviour is observed in plant cells subjected to hyperosmotic stress but also takes place in physiological conditions (e.g. during stomatal closure). Although vacuolar convolution is a relatively common phenomenon in plants, studies aimed at elucidating its execution mechanisms are rather scarce. In the present review, we analyse the available evidence on the participation of the cellular cytoskeleton and ion transporters in vacuolar morphology dynamics, putting special emphasis on the available evidence of the role played by phosphatidylinositol 3,5-bisphosphate in this process.
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Affiliation(s)
- Vadim Pérez Koldenkova
- Laboratorio Nacional de Microscopía Avanzada, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Av. Cuauhtémoc, 330, Col. Doctores, Del. Cuauhtémoc. 06720, México D.F., Mexico
| | - Noriyuki Hatsugai
- Department of Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota St Paul, MN 55108, USA
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13
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Garagounis C, Kostaki KI, Hawkins TJ, Cummins I, Fricker MD, Hussey PJ, Hetherington AM, Sweetlove LJ. Microcompartmentation of cytosolic aldolase by interaction with the actin cytoskeleton in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:885-898. [PMID: 28338736 DOI: 10.1093/jxb/erx015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Evidence is accumulating for molecular microcompartments formed when proteins interact in localized domains with the cytoskeleton, organelle surfaces, and intracellular membranes. To understand the potential functional significance of protein microcompartmentation in plants, we studied the interaction of the glycolytic enzyme fructose bisphosphate aldolase with actin in Arabidopsis thaliana. Homology modelling of a major cytosolic isozyme of aldolase, FBA8, suggested that the tetrameric holoenzyme has two actin binding sites and could therefore act as an actin-bundling protein, as was reported for animal aldolases. This was confirmed by in vitro measurements of an increase in viscosity of F-actin polymerized in the presence of recombinant FBA8. Simultaneously, interaction with F-actin caused non-competitive inhibition of aldolase activity. We did not detect co-localization of an FBA8-RFP fusion protein, expressed in an fba8-knockout background, with the actin cytoskeleton using confocal laser-scanning microscopy. However, we did find evidence for a low level of interaction using FRET-FLIM analysis of FBA8-RFP co-expressed with the actin-binding protein GFP-Lifeact. Furthermore, knockout of FBA8 caused minor alterations of guard cell actin cytoskeleton morphology and resulted in a reduced rate of stomatal closure in response to decreased humidity. We conclude that cytosolic aldolase can be microcompartmented in vivo by interaction with the actin cytoskeleton and may subtly modulate guard cell behaviour as a result.
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Affiliation(s)
- Constantine Garagounis
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
| | - Kalliopi-Ioanna Kostaki
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Tim J Hawkins
- School of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - Ian Cummins
- School of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - Mark D Fricker
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
| | - Patrick J Hussey
- School of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - Alistair M Hetherington
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Lee J Sweetlove
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
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Zhao S, Jiang Y, Zhao Y, Huang S, Yuan M, Zhao Y, Guo Y. CASEIN KINASE1-LIKE PROTEIN2 Regulates Actin Filament Stability and Stomatal Closure via Phosphorylation of Actin Depolymerizing Factor. THE PLANT CELL 2016; 28:1422-39. [PMID: 27268429 PMCID: PMC4944410 DOI: 10.1105/tpc.16.00078] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/06/2016] [Indexed: 05/03/2023]
Abstract
The opening and closing of stomata are crucial for plant photosynthesis and transpiration. Actin filaments undergo dynamic reorganization during stomatal closure, but the underlying mechanism for this cytoskeletal reorganization remains largely unclear. In this study, we identified and characterized Arabidopsis thaliana casein kinase 1-like protein 2 (CKL2), which responds to abscisic acid (ABA) treatment and participates in ABA- and drought-induced stomatal closure. Although CKL2 does not bind to actin filaments directly and has no effect on actin assembly in vitro, it colocalizes with and stabilizes actin filaments in guard cells. Further investigation revealed that CKL2 physically interacts with and phosphorylates actin depolymerizing factor 4 (ADF4) and inhibits its activity in actin filament disassembly. During ABA-induced stomatal closure, deletion of CKL2 in Arabidopsis alters actin reorganization in stomata and renders stomatal closure less sensitive to ABA, whereas deletion of ADF4 impairs the disassembly of actin filaments and causes stomatal closure to be more sensitive to ABA Deletion of ADF4 in the ckl2 mutant partially recues its ABA-insensitive stomatal closure phenotype. Moreover, Arabidopsis ADFs from subclass I are targets of CKL2 in vitro. Thus, our results suggest that CKL2 regulates actin filament reorganization and stomatal closure mainly through phosphorylation of ADF.
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Affiliation(s)
- Shuangshuang Zhao
- Key Laboratory of Plant Stress, Life Science College, Shandong Normal University, Jinan 250014, China State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yuxiang Jiang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Science, Beijing 100093, China
| | - Yang Zhao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shanjin Huang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Science, Beijing 100093, China Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ming Yuan
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yanxiu Zhao
- Key Laboratory of Plant Stress, Life Science College, Shandong Normal University, Jinan 250014, China
| | - Yan Guo
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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15
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Raorane ML, Pabuayon IM, Miro B, Kalladan R, Reza-Hajirezai M, Oane RH, Kumar A, Sreenivasulu N, Henry A, Kohli A. Variation in primary metabolites in parental and near-isogenic lines of the QTL qDTY12.1 : altered roots and flag leaves but similar spikelets of rice under drought. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2015; 35:138. [PMID: 26069451 PMCID: PMC4451464 DOI: 10.1007/s11032-015-0322-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/06/2015] [Indexed: 05/18/2023]
Abstract
There is a widespread consensus that drought will mostly affect present and future agriculture negatively. Generating drought-tolerant crops is thus a high priority. However complicated the underlying genetic and regulatory networks for differences in plant performance under stress are, they would be reflected in straightforward differences in primary metabolites. This is because primary metabolites such as amino acids and sugars form the building blocks of all pathways and processes for growth, development, reproduction, and environmental responses. Comparison of such differences was undertaken between the parental line and a near-isogenic line of qDTY12.1 , a QTL for rice yield under drought. The comparison was informative regarding the effect of the QTL in three genetic backgrounds: donor, recipient, and improved recipient, thus illustrating the gene × gene (G × G) interactions. Such a comparison when extended to well-watered and drought conditions illustrated the gene × environment (G × E) interactions. Assessment of such G × G and G × E responses in roots, flag leaves, and spikelets added a yet more informative dimension of tissue-specific responses to drought, mediated by qDTY12.1 . Data on variation in primary metabolites subjected to ANOVA, Tukey's test, Welch's t test, and PCA underscored the importance of the roots and demonstrated concordance between variation in metabolites and morpho-physiological responses to drought. Results suggested that for gainful insights into rice yield under drought, rather than vegetative stage drought tolerance, multiple tissues and genotypes must be assessed at the reproductive stage to avoid misleading conclusions about using particular metabolites or related genes and proteins as candidates or markers for drought tolerance.
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Affiliation(s)
- Manish L. Raorane
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
| | - Isaiah M. Pabuayon
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
| | - Berta Miro
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
| | - Rajesh Kalladan
- />Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 03, 06466 Gatersleben, Germany
- />Institute of Plant and Microbial Biology, Academia Sinica, 128 Sec. 2, Academia Road, Nankang, Taipei 11529 Taiwan
| | - Mohammad Reza-Hajirezai
- />Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 03, 06466 Gatersleben, Germany
| | - Rowena H. Oane
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
| | - Arvind Kumar
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
| | - Nese Sreenivasulu
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
- />Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 03, 06466 Gatersleben, Germany
| | - Amelia Henry
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
| | - Ajay Kohli
- />International Rice Research Institute (IRRI), DAPO 7777, Metro Manila, Philippines
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16
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Isayenkov SV, Sekan AS, Sorochinsky BV, Blume YB. Molecular aspects of endosomal cellular transport. CYTOL GENET+ 2015. [DOI: 10.3103/s009545271503007x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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McLachlan DH, Kopischke M, Robatzek S. Gate control: guard cell regulation by microbial stress. THE NEW PHYTOLOGIST 2014; 203:1049-1063. [PMID: 25040778 DOI: 10.1111/nph.12916] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/26/2014] [Indexed: 05/07/2023]
Abstract
Terrestrial plants rely on stomata, small pores in the leaf surface, for photosynthetic gas exchange and transpiration of water. The stomata, formed by a pair of guard cells, dynamically increase and decrease their volume to control the pore size in response to environmental cues. Stresses can trigger similar or opposing movements: for example, drought induces closure of stomata, whereas many pathogens exploit stomata and cause them to open to facilitate entry into plant tissues. The latter is an active process as stomatal closure is part of the plant's immune response. Stomatal research has contributed much to clarify the signalling pathways of abiotic stress, but guard cell signalling in response to microbes is a relatively new area of research. In this article, we discuss present knowledge of stomatal regulation in response to microbes and highlight common points of convergence, and differences, compared to stomatal regulation by abiotic stresses. We also expand on the mechanisms by which pathogens manipulate these processes to promote disease, for example by delivering effectors to inhibit closure or trigger opening of stomata. The study of pathogen effectors in stomatal manipulation will aid our understanding of guard cell signalling.
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Affiliation(s)
| | | | - Silke Robatzek
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
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18
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Guan X, Buchholz G, Nick P. Actin marker lines in grapevine reveal a gatekeeper function of guard cells. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:1164-1173. [PMID: 24973589 DOI: 10.1016/j.jplph.2014.03.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 01/26/2014] [Accepted: 03/11/2014] [Indexed: 06/03/2023]
Abstract
Resistance to abiotic and biotic stress is a central topic for sustainable agriculture, especially in grapevine, one of the field crops with the highest economic output per acreage. As early cellular factors for plant defense, actin microfilaments (AF) are of high relevance. We therefore generated a transgenic actin marker line for grapevine by expressing a fusion protein between green fluorescent protein and the second actin-binding domain of Arabidopsis (Arabidopsis thaliana) fimbrin, AtFIM1. Based on this first cytoskeletal-marker line in grapevine, the response of AFs to phytopathogenic microorganisms could be followed in vivo. Upon inoculation with fluorescently labeled strains of phytopathogenic bacteria, actin responses were confined to the guard cells. In contrast, upon contact with zoospores of Plasmopara viticola, not only the guard cells, but also epidermal pavement cells, where no zoospores had attached responded with the formation of a perinuclear actin basket. Our data support the hypothesis that guard cells act as pacemakers of defense, dominating the responses of the remaining epidermal cells.
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Affiliation(s)
- Xin Guan
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76128 Karlsruhe, Germany; College of Horticulture and Landscape Architecture, Southwest University, 400716 Chongqing, China.
| | - Günther Buchholz
- RLP AgroScience/AlPlanta - Institute for Plant Research, Breitenweg 71, D-67435 Neustadt an der Weinstraße, Germany
| | - Peter Nick
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76128 Karlsruhe, Germany
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19
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Li X, Li JH, Wang W, Chen NZ, Ma TS, Xi YN, Zhang XL, Lin HF, Bai Y, Huang SJ, Chen YL. ARP2/3 complex-mediated actin dynamics is required for hydrogen peroxide-induced stomatal closure in Arabidopsis. PLANT, CELL & ENVIRONMENT 2014; 37:1548-60. [PMID: 24372484 DOI: 10.1111/pce.12259] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/21/2013] [Accepted: 12/08/2013] [Indexed: 05/03/2023]
Abstract
Multiple cellular events like dynamic actin reorganization and hydrogen peroxide (H(2)O(2)) production were demonstrated to be involved in abscisic acid (ABA)-induced stomatal closure. However, the relationship between them as well as the underlying mechanisms remains poorly understood. Here, we showed that H(2)O(2) generation is indispensable for ABA induction of actin reorganization in guard cells of Arabidopsis that requires the presence of ARP2/3 complex. H(2)O(2) -induced stomatal closure was delayed in the mutants of arpc4 and arpc5, and the rate of actin reorganization was slowed down in arpc4 and arpc5 in response to H(2)O(2), suggesting that ARP2/3-mediated actin nucleation is required for H(2)O(2) -induced actin cytoskeleton remodelling. Furthermore, the expression of H(2)O(2) biosynthetic related gene AtrbohD and the accumulation of H(2)O(2) was delayed in response to ABA in arpc4 and arpc5, demonstrating that misregulated actin dynamics affects H(2)O(2) production upon ABA treatment. These results support a possible causal relation between the production of H(2)O(2) and actin dynamics in ABA-mediated guard cell signalling: ABA triggers H(2)O(2) generation that causes the reorganization of the actin cytoskeleton partially mediated by ARP2/3 complex, and ARP2/3 complex-mediated actin dynamics may feedback regulate H(2)O(2) production.
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Affiliation(s)
- Xin Li
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
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20
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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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21
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Hafke JB, Ehlers K, Föller J, Höll SR, Becker S, van Bel AJE. Involvement of the sieve element cytoskeleton in electrical responses to cold shocks. PLANT PHYSIOLOGY 2013; 162:707-19. [PMID: 23624858 PMCID: PMC3668064 DOI: 10.1104/pp.113.216218] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This study dealt with the visualization of the sieve element (SE) cytoskeleton and its involvement in electrical responses to local cold shocks, exemplifying the role of the cytoskeleton in Ca(2+)-triggered signal cascades in SEs. High-affinity fluorescent phalloidin as well as immunocytochemistry using anti-actin antibodies demonstrated a fully developed parietal actin meshwork in SEs. The involvement of the cytoskeleton in electrical responses and forisome conformation changes as indicators of Ca(2+) influx was investigated by the application of cold shocks in the presence of diverse actin disruptors (latrunculin A and cytochalasin D). Under control conditions, cold shocks elicited a graded initial voltage transient, ΔV1, reduced by external La(3+) in keeping with the involvement of Ca(2+) channels, and a second voltage transient, ΔV2. Cytochalasin D had no effect on ΔV1, while ΔV1 was significantly reduced with 500 nm latrunculin A. Forisome dispersion was triggered by cold shocks of 4°C or greater, which was indicative of an all-or-none behavior. Forisome dispersion was suppressed by incubation with latrunculin A. In conclusion, the cytoskeleton controls cold shock-induced Ca(2+) influx into SEs, leading to forisome dispersion and sieve plate occlusion in fava bean (Vicia faba).
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Affiliation(s)
- Jens B Hafke
- Plant Cell Physiology Group, Institute of Plant Physiology, Justus-Liebig-University, D-35390 Giessen, Germany.
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22
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Bak G, Lee EJ, Lee Y, Kato M, Segami S, Sze H, Maeshima M, Hwang JU, Lee Y. Rapid structural changes and acidification of guard cell vacuoles during stomatal closure require phosphatidylinositol 3,5-bisphosphate. THE PLANT CELL 2013; 25:2202-16. [PMID: 23757398 PMCID: PMC3723621 DOI: 10.1105/tpc.113.110411] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 05/13/2013] [Accepted: 05/23/2013] [Indexed: 05/08/2023]
Abstract
Rapid stomatal closure is essential for water conservation in plants and is thus critical for survival under water deficiency. To close stomata rapidly, guard cells reduce their volume by converting a large central vacuole into a highly convoluted structure. However, the molecular mechanisms underlying this change are poorly understood. In this study, we used pH-indicator dyes to demonstrate that vacuolar convolution is accompanied by acidification of the vacuole in fava bean (Vicia faba) guard cells during abscisic acid (ABA)-induced stomatal closure. Vacuolar acidification is necessary for the rapid stomatal closure induced by ABA, since a double mutant of the vacuolar H(+)-ATPase vha-a2 vha-a3 and vacuolar H(+)-PPase mutant vhp1 showed delayed stomatal closure. Furthermore, we provide evidence for the critical role of phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] in changes in pH and morphology of the vacuole. Single and double Arabidopsis thaliana null mutants of phosphatidylinositol 3-phosphate 5-kinases (PI3P5Ks) exhibited slow stomatal closure upon ABA treatment compared with the wild type. Moreover, an inhibitor of PI3P5K reduced vacuolar acidification and convolution and delayed stomatal closure in response to ABA. Taken together, these results suggest that rapid ABA-induced stomatal closure requires PtdIns(3,5)P2, which is essential for vacuolar acidification and convolution.
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Affiliation(s)
- Gwangbae Bak
- POSTECH-UZH Cooperative Laboratory, Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Eun-Jung Lee
- POSTECH-UZH Global Research Laboratory, Department of Integrative Bioscience and Biotechnology, World Class University Program, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Yuree Lee
- POSTECH-UZH Cooperative Laboratory, Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Mariko Kato
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Shoji Segami
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Heven Sze
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815
| | - Masayoshi Maeshima
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Jae-Ung Hwang
- POSTECH-UZH Cooperative Laboratory, Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Youngsook Lee
- POSTECH-UZH Global Research Laboratory, Department of Integrative Bioscience and Biotechnology, World Class University Program, Pohang University of Science and Technology, Pohang 790-784, Korea
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23
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Li LJ, Ren F, Gao XQ, Wei PC, Wang XC. The reorganization of actin filaments is required for vacuolar fusion of guard cells during stomatal opening in Arabidopsis. PLANT, CELL & ENVIRONMENT 2013; 36:484-97. [PMID: 22891733 DOI: 10.1111/j.1365-3040.2012.02592.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The reorganization of actin filaments (AFs) and vacuoles in guard cells is involved in the regulation of stomatal movement. However, it remains unclear whether there is any interaction between the reorganization of AFs and vacuolar changes during stomatal movement. Here, we report the relationship between the reorganization of AFs and vacuolar fusion revealed in pharmacological experiments, and characterizing stomatal opening in actin-related protein 2 (arp2) and arp3 mutants. Our results show that cytochalasin-D-induced depolymerization or phalloidin-induced stabilization of AFs leads to an increase in small unfused vacuoles during stomatal opening in wild-type (WT) Arabidopsis plants. Light-induced stomatal opening is retarded and vacuolar fusion in guard cells is impaired in the mutants, in which the reorganization and the dynamic parameters of AFs are aberrant compared with those of the WT. In WT, AFs tightly surround the small separated vacuoles, forming a ring that encircles the boundary membranes of vacuoles partly fused during stomatal opening. In contrast, in the mutants, most AFs and actin patches accumulate abnormally around the nuclei of the guard cells, which probably further impair vacuolar fusion and retard stomatal opening. Our results suggest that the reorganization of AFs regulates vacuolar fusion in guard cells during stomatal opening.
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Affiliation(s)
- Li-Juan Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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24
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Kong SG, Kagawa T, Wada M, Nagatani A. A C-terminal membrane association domain of phototropin 2 is necessary for chloroplast movement. PLANT & CELL PHYSIOLOGY 2013; 54:57-68. [PMID: 23012349 DOI: 10.1093/pcp/pcs132] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Phototropins (phot1 and phot2), plant-specific blue light receptor kinases, mediate a range of physiological responses in Arabidopsis, including phototropism, chloroplast photorelocation movement, stomatal opening and leaf flattening. Phototropins consist of two photoreceptive domains at their N-terminus, LOV1 (light, oxygen or voltage 1) and LOV2, and a serine/threonine kinase domain at their C-terminus. Here, we determined the molecular moiety for the membrane association of phototropins using the yeast CytoTrap and Arabidopsis protoplast systems. We then examined the physiological significance of the membrane association of phototropins. This detailed study with serial deletions narrowed down the association domain to a relatively small part of the C-terminal domain of phototropin. The functional analysis of phot2 deletion mutants in the phot2-deficient Adiantum and Arabidopsis mutants revealed that the ability to mediate the chloroplast avoidance response correlated well with phot2's membrane association, especially with the Golgi apparatus. Taken together, our data suggest that a small part of the C-terminal domain of phototropins is necessary not only for membrane association but also for the physiological activities that elicit phototropin-specific responses.
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Affiliation(s)
- Sam-Geun Kong
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan.
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25
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Jiang K, Sorefan K, Deeks MJ, Bevan MW, Hussey PJ, Hetherington AM. The ARP2/3 complex mediates guard cell actin reorganization and stomatal movement in Arabidopsis. THE PLANT CELL 2012; 24:2031-40. [PMID: 22570440 PMCID: PMC3442585 DOI: 10.1105/tpc.112.096263] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Revised: 03/29/2012] [Accepted: 04/16/2012] [Indexed: 05/19/2023]
Abstract
Guard cell actin reorganization has been observed in stomatal responses to a wide array of stimuli. However, how the guard cell signaling machinery regulates actin dynamics is poorly understood. Here, we report the identification of an allele of the Arabidopsis thaliana ACTIN-RELATED PROTEIN C2/DISTORTED TRICHOMES2 (ARPC2) locus (encoding the ARPC2 subunit of the ARP2/3 complex) designated high sugar response3 (hsr3). The hsr3 mutant showed increased transpirational water loss that was mainly due to a lesion in stomatal regulation. Stomatal bioassay analyses revealed that guard cell sensitivity to external stimuli, such as abscisic acid (ABA), CaCl(2), and light/dark transition, was reduced or abolished in hsr3. Analysis of a nonallelic mutant of the ARP2/3 complex suggested no pleiotropic effect of ARPC2 beyond its function in the complex in regard to stomatal regulation. When treated with ABA, guard cell actin filaments underwent fast disruption in wild-type plants, whereas those in hsr3 remained largely bundled. The ABA insensitivity phenotype of hsr3 was rescued by cytochalasin D treatment, suggesting that the aberrant stomatal response was a consequence of bundled actin filaments. Our work indicates that regulation of actin reassembly through ARP2/3 complex activity is crucial for stomatal regulation.
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Affiliation(s)
- Kun Jiang
- School of Biological Sciences, University of Bristol, Bristol BS8 1UG, United Kingdom
| | - Karim Sorefan
- Cell and Developmental Biology Department, John Innes Centre, Norwich, Norfolk NR4 7UH, United Kingdom
| | - Michael J. Deeks
- School of Biological and Biomedical Sciences, University of Durham, Durham DH1 3LE, United Kingdom
| | - Michael W. Bevan
- Cell and Developmental Biology Department, John Innes Centre, Norwich, Norfolk NR4 7UH, United Kingdom
| | - Patrick J. Hussey
- School of Biological and Biomedical Sciences, University of Durham, Durham DH1 3LE, United Kingdom
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26
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Roshchina VV, Yashin VA, Vikhlyantsev IM. Fluorescence of plant microspores as biosensors. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2012. [DOI: 10.1134/s1990747811060122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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Zhao Y, Zhao S, Mao T, Qu X, Cao W, Zhang L, Zhang W, He L, Li S, Ren S, Zhao J, Zhu G, Huang S, Ye K, Yuan M, Guo Y. The plant-specific actin binding protein SCAB1 stabilizes actin filaments and regulates stomatal movement in Arabidopsis. THE PLANT CELL 2011; 23:2314-30. [PMID: 21719691 PMCID: PMC3160031 DOI: 10.1105/tpc.111.086546] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 05/28/2011] [Accepted: 06/10/2011] [Indexed: 05/18/2023]
Abstract
Microfilament dynamics play a critical role in regulating stomatal movement; however, the molecular mechanism underlying this process is not well understood. We report here the identification and characterization of STOMATAL CLOSURE-RELATED ACTIN BINDING PROTEIN1 (SCAB1), an Arabidopsis thaliana actin binding protein. Plants lacking SCAB1 were hypersensitive to drought stress and exhibited reduced abscisic acid-, H(2)O(2)-, and CaCl(2)-regulated stomatal movement. In vitro and in vivo analyses revealed that SCAB1 binds, stabilizes, and bundles actin filaments. SCAB1 shares sequence similarity only with plant proteins and contains a previously undiscovered actin binding domain. During stomatal closure, actin filaments switched from a radial orientation in open stomata to a longitudinal orientation in closed stomata. This switch took longer in scab1 plants than in wild-type plants and was correlated with the delay in stomatal closure seen in scab1 mutants in response to drought stress. Our results suggest that SCAB1 is required for the precise regulation of actin filament reorganization during stomatal closure.
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Affiliation(s)
- Yang Zhao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- National Institute of Biological Sciences, Beijing 102206, China
| | - Shuangshuang Zhao
- Key Laboratory of Plant Stress, Life Science College, Shandong Normal University, Jinan 250014, China
| | - Tonglin Mao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaolu Qu
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Wanhong Cao
- National Institute of Biological Sciences, Beijing 102206, China
| | - Li Zhang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Wei Zhang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Liu He
- National Institute of Biological Sciences, Beijing 102206, China
| | - Sidi Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - Sulin Ren
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jinfeng Zhao
- National Institute of Biological Sciences, Beijing 102206, China
| | - Guoli Zhu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shanjin Huang
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Keqiong Ye
- National Institute of Biological Sciences, Beijing 102206, China
| | - Ming Yuan
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yan Guo
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- Address correspondence to
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Königer M, Jessen B, Yang R, Sittler D, Harris GC. Light, genotype, and abscisic acid affect chloroplast positioning in guard cells of Arabidopsis thaliana leaves in distinct ways. PHOTOSYNTHESIS RESEARCH 2010; 105:213-227. [PMID: 20614182 DOI: 10.1007/s11120-010-9580-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2009] [Accepted: 06/24/2010] [Indexed: 05/29/2023]
Abstract
The goal of this study was to investigate the effects of light intensity, genotype, and various chemical treatments on chloroplast movement in guard cells of Arabidopsis thaliana leaves. After treatment at various light intensities (dark, low, and high light), leaf discs were fixed with glutaraldehyde, and imaged using confocal laser microscopy. Each chloroplast was assigned a horizontal (close to pore, center, or epidermal side) and vertical (outer, middle, inner) position. White light had a distinct effect on chloroplast positioning, most notably under high light (HL) when chloroplasts on the upper leaf surface of wild-type (WT) moved from epidermal and center positions toward the pore. This was not the case for phot1-5/phot2-1 or phot2-1 plants, thus phototropins are essential for chloroplast positioning in guard cells. In npq1-2 mutants, fewer chloroplasts moved to the pore position under HL than in WT plants, indicating that white light can affect chloroplast positioning also in a zeaxanthin-dependent way. Cytochalasin B inhibited the movement of chloroplasts to the pore under HL, while oryzalin did not, supporting the idea that actin plays a role in the movement. The movement along actin cables is dependent on CHUP1 since chloroplast positioning in chup1 was significantly altered. Abscisic acid (ABA) caused most chloroplasts in WT and phot1-5/phot2-1 to be localized in the center, middle part of the guard cells irrespective of light treatment. This indicates that not only light but also water stress influences chloroplast positioning.
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Affiliation(s)
- Martina Königer
- Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA.
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29
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Kriegs B, Jansen M, Hahn K, Peisker H, Šamajová O, Beck M, Braun S, Ulbrich A, Baluška F, Schulz M. Cyclic monoterpene mediated modulations of Arabidopsis thaliana phenotype: effects on the cytoskeleton and on the expression of selected genes. PLANT SIGNALING & BEHAVIOR 2010; 5:832-8. [PMID: 20484979 PMCID: PMC3115032 DOI: 10.4161/psb.5.7.12032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 02/26/2010] [Accepted: 04/07/2010] [Indexed: 05/07/2023]
Abstract
Monoterpenes at high atmospheric concentrations are strong growth inhibitors in allelopathic interactions. Effects depend on dose, molecular structure of the monoterpene and on the species of the receiver plant. Stomata are among the first targets affected by camphor and menthol. Previously, it could be demonstrated that the compounds induce swelling of the protoplasts, prevent stomatal closure and enhance transpiration. In this study, we show that the block of stomatal closure is accompanied by changes to the cytoskeleton, which has a direct role in stomatal movements. Although MPK3 (MAP3 kinase) and ABF4 gene expressions are induced within six hours, stomatal closure is prevented. In contrast to ABF4, ABF2 (both transcription factors) is not induced. MPK3 and ABF4 both encode for proteins involved in the process of stomatal closure. The expression of PEPCase, an enzyme important for stomatal opening, is down regulated. The leaves develop stress symptoms, mirrored by transient changes in the expression profile of additional genes: lipoxygenase 2 (LOX2), CER5, CER6 (both important for wax production) and RD29B (an ABA inducible stress protein). Non-invasive methods showed a fast response of the plant to camphor fumigations both in a rapid decrease of the quantum yield and in the relative growth rate. Repeated exposures to the monoterpenes resulted finally in growth reduction and a stress related change in the phenotype. It is proposed that high concentrations or repeated exposure to monoterpenes led to irreversible damages, whereas low concentrations or short-term fumigations may have the potential to strengthen the plant fitness.
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Affiliation(s)
- Bettina Kriegs
- IMBIO (Institut für Molekulare Physiologie und Biotechnologie der Pflanzen); Universität Bonn; Bonn, Germany
| | - Marcus Jansen
- ICG-3-Phytosphäre; Forschungszentrum Jülich GmbH; Jülich, Germany
| | - Katrin Hahn
- IMBIO (Institut für Molekulare Physiologie und Biotechnologie der Pflanzen); Universität Bonn; Bonn, Germany
| | - Helga Peisker
- IMBIO (Institut für Molekulare Physiologie und Biotechnologie der Pflanzen); Universität Bonn; Bonn, Germany
| | - Olga Šamajová
- IZMB (Institut für Zelluläre und Molekulare Botanik) Universität Bonn; Bonn, Germany
- Centre of the Region Hana for Biotechnological and Agricultural Research; Faculty of Science; Palacky University; Olomouc, Czech Republic
| | - Martina Beck
- IZMB (Institut für Zelluläre und Molekulare Botanik) Universität Bonn; Bonn, Germany
| | - Silvia Braun
- ICG-3-Phytosphäre; Forschungszentrum Jülich GmbH; Jülich, Germany
| | - Andreas Ulbrich
- ICG-3-Phytosphäre; Forschungszentrum Jülich GmbH; Jülich, Germany
- Fachhochschule Osnabrück; Gemüseproduktion und Verarbeitung; Osnabrück, Germany
| | - František Baluška
- IZMB (Institut für Zelluläre und Molekulare Botanik) Universität Bonn; Bonn, Germany
| | - Margot Schulz
- IMBIO (Institut für Molekulare Physiologie und Biotechnologie der Pflanzen); Universität Bonn; Bonn, Germany
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Zhang W, Fan LM. Actin dynamics regulates voltage-dependent calcium-permeable channels of the Vicia faba guard cell plasma membrane. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2009; 51:912-21. [PMID: 19778401 DOI: 10.1111/j.1744-7909.2009.00859.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Free cytosolic Ca(2+) ([Ca(2+)](cyt)) is an ubiquitous second messenger in plant cell signaling, and [Ca(2+)](cyt) elevation is associated with Ca(2+)-permeable channels in the plasma membrane and endomembranes regulated by a wide range of stimuli. However, knowledge regarding Ca(2+) channels and their regulation remains limited in planta. A type of voltage-dependent Ca(2+)-permeable channel was identified and characterized for the Vicia faba L. guard cell plasma membrane by using patch-clamp techniques. These channels are permeable to both Ba(2+) and Ca(2+), and their activities can be inhibited by micromolar Gd(3+). The unitary conductance and the reversal potential of the channels depend on the Ca(2+) or Ba(2+) gradients across the plasma membrane. The inward whole-cell Ca(2+) (Ba(2+)) current, as well as the unitary current amplitude and NP(o) of the single Ca(2+) channel, increase along with the membrane hyperpolarization. Pharmacological experiments suggest that actin dynamics may serve as an upstream regulator of this type of calcium channel of the guard cell plasma membrane. Cytochalasin D, an actin polymerization blocker, activated the NPo of these channels at the single channel level and increased the current amplitude at the whole-cell level. But these channel activations and current increments could be restrained by pretreatment with an F-actin stabilizer, phalloidin. The potential physiological significance of this regulatory mechanism is also discussed.
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Affiliation(s)
- Wei Zhang
- National Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China
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Gao XQ, Wang XL, Ren F, Chen J, Wang XC. Dynamics of vacuoles and actin filaments in guard cells and their roles in stomatal movement. PLANT, CELL & ENVIRONMENT 2009; 32:1108-16. [PMID: 19422610 DOI: 10.1111/j.1365-3040.2009.01993.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Vacuoles and actin filaments are important cytoarchitectures involved in guard cell function. The changes in the morphology and number of vacuoles and the regulation of ion channel activity in tonoplast of guard cells are essential for stomatal movement. A number of studies have investigated the regulation of ion channels in animal and plant cells; however, little is known about the regulating mechanism for vacuolar dynamics in stomatal movement. Actin filaments of guard cells are remodelling with the changes in the stomatal aperture; however, the dynamic functions of actin filaments in stomatal movement remain elusive. In this paper, we summarize the recent developments in the understanding of the dynamics of actin filaments and vacuoles of guard cells during stomatal movement. All relevant studies suggest that actin filaments might be involved in stomatal movement by regulating vacuolar dynamics and the ion channels in tonoplast. The future study could be focused on the linker protein mediating the interaction between actin filaments and tonoplast, which will provide insights into the interactive function of actin and vacuole in stomatal movement regulation.
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Affiliation(s)
- Xin-Qi Gao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, Taiwan
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32
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Huang AX, She XP, Cao B, Zhang B, Mu J, Zhang SJ. Nitric oxide, actin reorganization and vacuoles change are involved in PEG 6000-induced stomatal closure in Vicia faba. PHYSIOLOGIA PLANTARUM 2009; 136:45-56. [PMID: 19508367 DOI: 10.1111/j.1399-3054.2009.01212.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Water deficit and the resulting osmotic stress affect stomatal movement. There are two types of signals, hydraulic and chemical signals, involving in the regulation of stomatal behavior responses to osmotic stress. Compared with the chemical signals, little has been known about the hydraulic signals and the corresponding signal transduction network and regulatory mechanisms. Here, using an epidermal-strip bioassay and laser-scanning confocal microscopy, we provide evidence that nitric oxide (NO) generation in Vicia faba guard cells can be induced by hydraulic signals. We used polyethylene glycol (PEG) 600 to simulate hypertonic conditions. This hydraulic signal led to stomatal closure and rapid promotion of NO production in guard cells. The effects were decreased by NO scavenger 2-(4-carboxyphenyl)-4,4,5, 5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) and NO synthase (Enzyme Commission 1.14.13.39) inhibitor N(G)-nitro-L-Arg-methyl ester (L-NAME). These results indicate that PEG 6000 induces stomatal closure by promoting NO production. Cytochalasin B (CB) inhibited stomatal closure induced by PEG 6000 but did not prevent the increase of endogenous NO levels, indicating that microfilaments polymerization participate in stomatal closure induced by PEG 6000, and may act downstream of NO signaling. In addition, big vacuoles split into many small vacuoles were observed in response to PEG 6000 and sodium nitroprusside (SNP) treatment, and CB inhibited these changes of vacuoles, the stomatal closure was also been inhibited. Collectively, these results suggest that the stomatal closure induced by PEG 6000 may be intimately associated with NO levels, reorganization of actin filaments and the changes of vacuoles, showing a crude outline of guard-cells signaling process in response to hydraulic signals.
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Affiliation(s)
- Ai-Xia Huang
- Key Laboratory of Medicinal Plant Resource and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
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33
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Gupta AK, Sinha S. Antioxidant response in sesame plants grown on industrially contaminated soil: effect on oil yield and tolerance to lipid peroxidation. BIORESOURCE TECHNOLOGY 2009; 100:179-85. [PMID: 18572402 DOI: 10.1016/j.biortech.2008.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 05/07/2008] [Accepted: 05/07/2008] [Indexed: 05/15/2023]
Abstract
The plants of sesame white (Sesamum indicum L. var. T55) grown on tannery sludge (TS) contaminated soil have shown that Cr level in the seeds was found below detection limits in 10% and 25% TS, however, the levels of Ni, Pb and Cd were found above the recommended limits. In roots, the level of antioxidants increased in the plants grown upto 35% TS at 30d over their respective controls. Total chlorophyll content increased significantly (p<0.5) in the plants (leaves) grown on lower sludge amendments (upto 35% TS at 30d and 25% TS at 60d) over their respective controls. In addition, the oil content increased (35% increase over control) in the plants grown on 35% TS. No significant change was observed in thiobarbituric acid reactive substances (TBARS), a lipid peroxidation index, in the plants (upto 50% TS). The number of trichomes in the leaves of treated plants was found more than control. In lower and upper leaves surfaces, the anterior end of the trichomes was found acute tipped and bent downwards, whereas, the trichome tip was straight and blunt in control. The stomata on upper and lower surfaces of the leaves were found partially or totally closed in the plants grown on 100% TS as compared to control. The toxicity was observed at higher amendments which are evident from the observed morphological changes and decrease in chlorophyll content. This study concludes that it is not advisable to grow the plants on contaminated area, besides its healthy growth.
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Affiliation(s)
- Amit K Gupta
- Ecotoxicology and Bioremediation, Environmental Sciences Division, National Botanical Research Institute, Lucknow, India
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Chaidee A, Foissner I, Pfeiffer W. Cell-specific association of heat shock-induced proton flux with actin ring formation in Chenopodium cells: comparison of auto- and heterotroph cultures. PROTOPLASMA 2008; 234:33-50. [PMID: 18807117 DOI: 10.1007/s00709-008-0013-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Accepted: 08/11/2008] [Indexed: 05/03/2023]
Abstract
A comparison of the responses of extracellular pH, buffering capacity and actin cytoskeleton in autotroph and heterotroph Chenopodium rubrum cells to heat shock revealed cell-specific reactions: alkalinization caused by the heat shock at 25-35 degrees C was higher in heterotroph cells and characterized by heat shock-induced changes in the actin cytoskeleton and ring formation at 35-37 degrees C. Rings (diameter up to 3 mum) disappeared and extracellular pH recovered after the heat-shocked cells were transferred into control medium. At 41 degrees C, no rings but a network of coarse actin filaments were induced; at higher temperatures, fragmentation of the actin cytoskeleton and release of buffering compounds occurred, indicating sudden membrane leakage at 45-47 degrees C. The calcium chelator EGTA [ethylene-glycol-bis(beta-aminoethyl-ether)-N,N,N',N'-tetraacetic-acid] increased the frequency of heat shock-induced rings. Ionophore (10 microM nigericin) and the sodium/proton antiport blocker [100 microM 5-(N-ethyl-N-isopropyl)-amiloride] mimicked the effect of the 37 degrees C heat shock. The cytoskeleton inhibitors latrunculin B, cytochalasin D and 2,3-butanedione monoxime inhibited ring formation but not alkalinization. In autotroph cells, the treatment with nigericin (10 microM) produced rings, although the actin cytoskeleton was not affected by temperatures up to 45 degrees C. We conclude that Chenopodium cells express a specific temperature sensor that has ascendancy over the organization of the actin cytoskeleton; this is probably a temperature- and potential-sensitive proton-transporting mechanism that is dependent on the culture conditions of the heterotroph cells.
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Affiliation(s)
- Anchalee Chaidee
- Department of Botany, Chulalongkorn University, Bangkok, Thailand
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35
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Gao XQ, Chen J, Wei PC, Ren F, Chen J, Wang XC. Array and distribution of actin filaments in guard cells contribute to the determination of stomatal aperture. PLANT CELL REPORTS 2008; 27:1655-65. [PMID: 18612643 DOI: 10.1007/s00299-008-0581-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 06/16/2008] [Accepted: 06/20/2008] [Indexed: 05/20/2023]
Abstract
Actin filaments in guard cells and their dynamics function in regulating stomatal movement. In this study, the array and distribution of actin filaments in guard cells during stomatal movement were studied with two vital labeling, microinjection of alexa-phalloidin in Vicia faba and expression of GFP-mTn in tobacco. We found that the random array of actin filaments in the most of the closed stomata changed to a ring-like array after stomatal open. And actin filaments, which were throughout the cytoplasm of guard cells of closed stomata (even distribution), were mainly found in the cortical cytoplasm in the case of open stomata (cortical distribution). These results revealed that the random array and even distribution of actin filaments in guard cells may be required for keeping the closed stomata; similarly, the ring-like array and cortical distribution of actin filaments function in sustaining open stomata. Furthermore, we found that actin depolymerization, the trait of moving stomata, facilitates the transformation of actin array and distribution with stomatal movement. So, the depolymerization of actin filaments was favorable for the changes of actin array and distribution in guard cells and thus facilitated stomatal movement.
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Affiliation(s)
- Xin-Qi Gao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University 100094, Beijing, People's Republic of China
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36
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The ABC transporter AtABCB14 is a malate importer and modulates stomatal response to CO2. Nat Cell Biol 2008; 10:1217-23. [PMID: 18776898 DOI: 10.1038/ncb1782] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 07/31/2008] [Indexed: 11/08/2022]
Abstract
Carbon dioxide uptake and water vapour release in plants occur through stomata, which are formed by guard cells. These cells respond to light intensity, CO2 and water availability, and plant hormones. The predicted increase in the atmospheric concentration of CO2 is expected to have a profound effect on our ecosystem. However, many aspects of CO2-dependent stomatal movements are still not understood. Here we show that the ABC transporter AtABCB14 modulates stomatal closure on transition to elevated CO2. Stomatal closure induced by high CO2 levels was accelerated in plants lacking AtABCB14. Apoplastic malate has been suggested to be one of the factors mediating the stomatal response to CO2 (Refs 4,5) and indeed, exogenously applied malate induced a similar AtABCB14-dependent response as high CO2 levels. In isolated epidermal strips that contained only guard cells, malate-dependent stomatal closure was faster in plants lacking the AtABCB14 and slower in AtABCB14-overexpressing plants, than in wild-type plants, indicating that AtABCB14 catalyses the transport of malate from the apoplast into guard cells. Indeed, when AtABCB14 was heterologously expressed in Escherichia coli and HeLa cells, increases in malate transport activity were observed. We therefore suggest that AtABCB14 modulates stomatal movement by transporting malate from the apoplast into guard cells, thereby increasing their osmotic pressure.
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37
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Choi Y, Lee Y, Jeon BW, Staiger CJ, Lee Y. Phosphatidylinositol 3- and 4-phosphate modulate actin filament reorganization in guard cells of day flower. PLANT, CELL & ENVIRONMENT 2008; 31:366-77. [PMID: 18088331 DOI: 10.1111/j.1365-3040.2007.01769.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Phosphatidylinositol 3-kinases (PtdIns 3-kinases) that produce phosphatidylinositol (3,4,5) triphosphate (PtdIns(3,4,5)P(3)) are considered to be important regulators of actin dynamics in animal cells. In plants, neither PtdIns(3,4,5)P(3) nor the enzyme that produces this lipid has been reported. However, a PtdIns 3-kinase that produces phosphatidylinositol 3-phosphate (PtdIns3P) has been identified, suggesting that PtdIns3P, instead of PtdIns(3,4,5)P(3), regulates actin dynamics in plant cells. Phosphatidylinositol 4-kinase (PtdIns 4-kinase) is closely associated with the actin cytoskeleton in plant cells, suggesting a role for this lipid kinase and its product phosphatidylinositol 4-phosphate (PtdIns4P) in actin-related processes. Here, we investigated whether or not PtdIns3P or PtdIns4P plays a role in actin reorganization induced by a plant hormone abscisic acid (ABA) in guard cells of day flower (Commelina communis). ABA-induced changes in actin filaments were inhibited by LY294002 (LY) and wortmannin (WM), inhibitors of PtdIns3P and PtdIns4P synthesis. Expression of PtdIns3P- and PtdIns4P-binding domains also inhibited ABA-induced actin reorganization in a manner similar to LY and WM. These results suggest that PtdIns3P and PtdIns4P regulate actin dynamics in guard cells. Furthermore, we demonstrate that PtdIns3P exerts its effect on actin dynamics, at least in part, via generation of reactive oxygen species (ROS) in response to ABA.
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Affiliation(s)
- Yunjung Choi
- Division of Molecular and Life Sciences, POSTECH, Pohang 790-784, Korea
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38
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Jeon BW, Hwang JU, Hwang Y, Song WY, Fu Y, Gu Y, Bao F, Cho D, Kwak JM, Yang Z, Lee Y. The Arabidopsis small G protein ROP2 is activated by light in guard cells and inhibits light-induced stomatal opening. THE PLANT CELL 2008; 20:75-87. [PMID: 18178769 PMCID: PMC2254924 DOI: 10.1105/tpc.107.054544] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 11/20/2007] [Accepted: 12/10/2007] [Indexed: 05/19/2023]
Abstract
ROP small G proteins function as molecular switches in diverse signaling processes. Here, we investigated signals that activate ROP2 in guard cells. In guard cells of Vicia faba expressing Arabidopsis thaliana constitutively active (CA) ROP2 fused to red fluorescent protein (RFP-CA-ROP2), fluorescence localized exclusively at the plasma membrane, whereas a dominant negative version of RFP-ROP2 (DN-ROP2) localized in the cytoplasm. In guard cells expressing green fluorescent protein-ROP2, the relative fluorescence intensity at the plasma membrane increased upon illumination, suggesting that light activates ROP2. Unlike previously reported light-activated factors, light-activated ROP2 inhibits rather than accelerates light-induced stomatal opening; stomata bordered by guard cells transformed with CA-rop2 opened less than controls upon light irradiation. When introduced into guard cells together with CA-ROP2, At RhoGDI1, which encodes a guanine nucleotide dissociation inhibitor, inhibited plasma membrane localization of CA-ROP2 and abolished the inhibitory effect of CA-ROP2 on light-induced stomatal opening, supporting the negative effect of active ROP2 on stomatal opening. Mutant rop2 Arabidopsis guard cells showed phenotypes similar to those of transformed V. faba guard cells; CA-rop2 stomata opened more slowly and to a lesser extent, and DN-rop2 stomata opened faster than wild-type stomata in response to light. Moreover, in rop2 knockout plants, stomata opened faster and to a greater extent than wild-type stomata in response to light. Thus, ROP2 is a light-activated negative factor that attenuates the extent of light-induced changes in stomatal aperture. The inhibition of light-induced stomatal opening by light-activated ROP2 suggests the existence of feedback regulatory mechanisms through which stomatal apertures may be finely controlled.
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Affiliation(s)
- Byeong Wook Jeon
- POSTECH-UZH Global Research Laboratories, Division of Molecular Life Sciences, POSTECH, Pohang 790-784, Korea
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39
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Zhang WH, Patrick JW, Tyerman SD. Actin filaments modulate hypoosmotic-responsive K + efflux channels in specialised cells of developing bean seed coats. FUNCTIONAL PLANT BIOLOGY : FPB 2007; 34:874-884. [PMID: 32689416 DOI: 10.1071/fp07138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Accepted: 07/24/2007] [Indexed: 06/11/2023]
Abstract
In developing bean (Phaseolus vulgaris L.) seeds, nutrients move in the symplasm from sieve elements to ground-parenchyma cells where they are transported across the plasma membrane into the seed apoplasm. Release of nutrients to the seed apoplasm is related to the osmotic conditions of the apoplasm. A hypoosmotic solution, resulting from enhanced uptake of nutrients by cotyledons, stimulates nutrient release from seed coat to the apoplasm. We investigated hypoosmotic nutrient release by examining the ionic membrane currents that respond to hypoosmotic treatment in protoplasts derived from three important cell types that occur at the seed coat-cotyledonary boundary. A non-selective but predominantly K+ efflux current that displayed a distinct time-dependent inactivation was elicited by membrane depolarisation under hypoosmotic conditions only in ground-parenchyma protoplasts. Hypoosmotic treatment had little effect on whole-cell ionic currents in protoplasts derived from coat chlorenchyma cells and cotyledon dermal cells. The inactivating K+ efflux current was elicited under isosmotic conditions by treatment with cytochalasin D, which disrupts actin filaments. Hypoosmotic treatment and cytochalasin D failed to induce the K+ current in ground-parenchyma protoplasts in the presence of the actin stabiliser, phalloidin. The net efflux of K+ from intact seed coats was enhanced by hypoosmotic treatment and cytochalasin D, and the stimulation of K+ efflux induced by the hypoosmotic treatment and cytochalasin D was abolished by phalloidin. A bursting Cl- channel previously described showed a similar pattern of responses. These results suggest that hypoosmotic-dependent KCl efflux from seed coats is mediated by the inactivating K+ outward current and bursting Cl- channel, and that actin filaments act as components of the transduction process that is a function of cell volume.
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Affiliation(s)
- Wen-Hao Zhang
- Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China
| | - John W Patrick
- School of Biological and Chemical Sciences, The University of Newcastle, Newcastle, NSW 2308, Australia
| | - Stephen D Tyerman
- School of Agriculture, Food and Wine, The University of Adelaide, PMB#1 Glen Osmond, SA 5064, Australia
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40
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Panteris E, Galatis B, Quader H, Apostolakos P. Cortical actin filament organization in developing and functioning stomatal complexes ofZea maysandTriticum turgidum. ACTA ACUST UNITED AC 2007; 64:531-48. [PMID: 17443701 DOI: 10.1002/cm.20203] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cortical actin filament (AF) organization was studied in detail in developing stomatal complexes of the grasses Zea mays and Triticum turgidum. AF arrays during the whole stomatal complex development are dynamic, partly following the pattern of cortical microtubule (MT) organization. They also exhibit particular patterns of organization, spatially and temporarily restricted. Among AF arrays, the radial ones that underlie young guard cell (GC) periclinal walls, those that line the bulbous GC ends and the AF ring at the junction between subsidiary cells (SCs) and GCs are described here for the first time. Although many similarities in cortical AF organization exist among the stomatal cells of both plants studied, considerable differences have also been observed between them. Our data reveal that the expanding areas of stomatal cell walls are lined by distinct cortical AF aggregations that probably protect the plasmalemma against mechanical stresses. Experimental AF disruption does not seem to affect detectably stomatal cell morphogenesis. Moreover, the structural and experimental data of this study revealed that, in contrast to the elliptical stomata, in the dumbbell-shaped ones the AFs and MTs seem not to be involved in the mechanism of opening and closing of the stomatal pore.
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Affiliation(s)
- Emmanuel Panteris
- Department of Botany, Faculty of Biology, University of Athens, Athens, Greece
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Homann U, Meckel T, Hewing J, Hütt MT, Hurst AC. Distinct fluorescent pattern of KAT1::GFP in the plasma membrane of Vicia faba guard cells. Eur J Cell Biol 2007; 86:489-500. [PMID: 17602785 DOI: 10.1016/j.ejcb.2007.05.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 05/15/2007] [Accepted: 05/15/2007] [Indexed: 11/19/2022] Open
Abstract
The organisation of membrane proteins into certain domains of the plasma membrane (PM) has been proposed to be important for signalling in yeast and animal cells. Here we describe the formation of a very distinct pattern of the K(+) channel KAT1 fused to the green fluorescent protein (KAT1::GFP) when transiently expressed in guard cells of Vicia faba. Using confocal laser scanning microscopy we observed a radially striped pattern of KAT1::GFP fluorescence in the PM in about 70% of all transfected guard cells. This characteristic pattern was found to be cell type and protein specific and independent of the stomatal aperture and the cytoskeleton. Staining of the cell wall of guard cells with Calcofluor White revealed a great similarity between the arrangement of cellulose microfibrils and the KAT1::GFP pattern. Furthermore, the radial pattern of KAT1::GFP immediately disappeared when turgor pressure was strongly decreased by changing from hypotonic to hypertonic conditions. The pattern reappeared within 15 min upon reestablishment of high turgor pressure in hypotonic solution. Evaluation of the staining pattern by a mathematical algorithm further confirmed this reversible abolishment of the radial pattern during hypertonic treatment. We therefore conclude that the radial organisation of KAT1::GFP depends on the close contact between the PM and cell wall in turgid guard cells. These results offer the first indication for a role of the cell wall in the localisation of ion channels. We propose a model in which KAT1 is located in the cellulose fibrils intermediate areas of the PM and discuss the physiological role of this phenomenon.
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Affiliation(s)
- Ulrike Homann
- Institute of Botany, University of Technology Darmstadt, Schnittspahnstrasse 3-5, 64287 Darmstadt, Germany
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Pandey S, Zhang W, Assmann SM. Roles of ion channels and transporters in guard cell signal transduction. FEBS Lett 2007; 581:2325-36. [PMID: 17462636 DOI: 10.1016/j.febslet.2007.04.008] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 04/03/2007] [Accepted: 04/03/2007] [Indexed: 12/16/2022]
Abstract
Stomatal complexes consist of pairs of guard cells and the pore they enclose. Reversible changes in guard cell volume alter the aperture of the pore and provide the major regulatory mechanism for control of gas exchange between the plant and the environment. Stomatal movement is facilitated by the activity of ion channels and ion transporters found in the plasma membrane and vacuolar membrane of guard cells. Progress in recent years has elucidated the molecular identities of many guard cell transport proteins, and described their modulation by various cellular signal transduction components during stomatal opening and closure prompted by environmental and endogenous stimuli.
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Affiliation(s)
- Sona Pandey
- Biology Department, Penn State University, 208 Mueller Laboratory, University Park, PA 16802, United States
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Moran N. Osmoregulation of leaf motor cells. FEBS Lett 2007; 581:2337-47. [PMID: 17434488 DOI: 10.1016/j.febslet.2007.04.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2007] [Revised: 03/31/2007] [Accepted: 04/02/2007] [Indexed: 11/18/2022]
Abstract
"Osmotic Motors"--the best-documented explanation for plant leaf movements--frequently reside in specialized motor leaf organs, pulvini. The movements result from dissimilar volume and turgor changes in two oppositely positioned parts of the pulvinus. This Osmotic Motor is powered by a plasma membrane proton ATPase, which drives KCl fluxes and, consequently, water, across the pulvinus into swelling cells and out of shrinking cells. Light signals and signals from the endogenous biological clock converge on the channels through which these fluxes occur. These channels and their regulatory pathways in the pulvinus are the topic of this review.
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Affiliation(s)
- Nava Moran
- The R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
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Lebaudy A, Véry AA, Sentenac H. K+ channel activity in plants: genes, regulations and functions. FEBS Lett 2007; 581:2357-66. [PMID: 17418142 DOI: 10.1016/j.febslet.2007.03.058] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Revised: 03/22/2007] [Accepted: 03/23/2007] [Indexed: 11/20/2022]
Abstract
Potassium (K(+)) is the most abundant cation in the cytosol, and plant growth requires that large amounts of K(+) are transported from the soil to the growing organs. K(+) uptake and fluxes within the plant are mediated by several families of transporters and channels. Here, we describe the different families of K(+)-selective channels that have been identified in plants, the so-called Shaker, TPK and Kir-like channels, and what is known so far on their regulations and physiological functions in the plant.
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Affiliation(s)
- Anne Lebaudy
- Biochimie et Physiologie Moléculaire des Plantes, UMR 5004, CNRS/INRA/Monptellier SupAgro/UM2, 1 Place Viala, 34060 Montpellier Cedex 1, France.
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45
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Sinha S, Mallick S, Misra RK, Singh S, Basant A, Gupta AK. Uptake and translocation of metals in Spinacia oleracea L. grown on tannery sludge-amended and contaminated soils: effect on lipid peroxidation, morpho-anatomical changes and antioxidants. CHEMOSPHERE 2007; 67:176-87. [PMID: 17095039 DOI: 10.1016/j.chemosphere.2006.08.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Revised: 08/07/2006] [Accepted: 08/23/2006] [Indexed: 05/12/2023]
Abstract
The plants of Spinacia oleracea L. grown on contaminated soil (CS) and different amendments of tannery sludge (TS) have shown high accumulation of metals in its edible part. The accumulation of toxic metal (Cr) in the leaves of the plants grown on CS was recorded as 40.67 microgg(-1)dw. However, the leaves of the plants grown on 100% TS have accumulated about two times (70.80 microgg(-1)dw) higher Cr than the 10% TS (31.21 microgg(-1)dw). Among growth parameters, the root length was more affected at 90 d than the shoot length, number of leaves and leaf area. The study of scanning electron micrographs showed 29.31% increase in stomatal length in the leaves of the plants grown on CS as compared to garden soil (GS), which served as control, however it decreased in the plants grown on higher amendments of TS. The decrease in MDA content at initial period of exposure and lower amendment was recorded in the leaves, whereas, significant increase (>10% TS onward) was observed with increase in tannery sludge ratio at 90 d as compared to GS. A coordinated increase in all the studied antioxidants (cysteine, non-protein thiol, ascorbic acid, carotenoid contents) was found up to 75 d of growth. At 90 d, most of the antioxidant decreased as compared to 75 d causing oxidative stress as evidenced by increased level of lipid peroxidation and decreased chlorophyll and protein contents. Maximum increase of 181.43% in MDA content and maximum decrease of 53.69% in total chlorophyll content was recorded in the leaves of the plants grown on 100% TS after 90 d of growth. The plants grown on CS have shown an increase in shoot length, number of leaves, leaf area, photosynthetic pigments and protein contents and in all the studied antioxidants. Thus, these plants are able to combat stress involving defense mechanism, resulting in healthy growth of the plants. The results are well coordinated as there is no change in the MDA content as compared to the plants grown on GS. In view of high Cr accumulation in edible part of S. oleracea grown on CS after irrigation with tap water, it is not advisable to use these plants for edible purposes. Summing up, it is recommended that the level of metals in the edible part should be checked instead of healthy growth as deciding parameter for consumption. It is demonstrated through this study that metal enriched plants have detoxification mechanism and grow well on organic matter enriched contaminated soil.
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Affiliation(s)
- Sarita Sinha
- Ecotoxicology and Bioremediation Group, National Botanical Research Institute, Lucknow 226 001, India.
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MacRobbie EAC, Kurup S. Signalling mechanisms in the regulation of vacuolar ion release in guard cells. THE NEW PHYTOLOGIST 2007; 175:630-640. [PMID: 17688580 DOI: 10.1111/j.1469-8137.2007.02131.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Pharmacological agents were used to investigate the possible involvement of actin in signalling chains associated with abscisic acid (ABA)-induced ion release from the guard cell vacuole, a process which is absolutely essential for stomatal closure. Effects on the ABA-induced transient stimulation of tonoplast efflux were measured, using (86)Rb in isolated guard cells of Commelina communis, together with effects on stomatal apertures. In the response to 10 microm ABA (triggered by Ca(2+) influx rather than internal Ca(2+) release), jasplakinolide (stabilizing actin filaments) and latrunculin B (depolymerizing actin filaments) had opposite effects. Both closure and the vacuolar efflux transient were inhibited by jasplakinolide but enhanced by latrunculin B. At 10 microm ABA prevention of mitogen-activated protein (MAP) kinase activation by PD98059 partially inhibited closure and reduced the efflux transient. By contrast, latrunculin B inhibited the efflux transient at 0.1 microm ABA (involving internal Ca(2+) release rather than Ca(2+) influx). The results suggest that 10 microm ABA activates Ca(2+)-dependent vacuolar ion efflux via a Ca(2+)-permeable influx channel which is maintained closed by interaction with F-actin. A MAP kinase is also involved, in a chain similar to that postulated for Ca(2+)-dependent gene expression in cold acclimation.
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Affiliation(s)
- Enid A C MacRobbie
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Smita Kurup
- Centre for Crop Genetic Improvement, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
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Scherer GFE. Halotolerance is enhanced in carrot callus by sensing hypergravity: influence of calcium modulators and cytochalasin D. PROTOPLASMA 2006; 229:149-54. [PMID: 17180496 DOI: 10.1007/s00709-006-0201-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2005] [Accepted: 08/24/2005] [Indexed: 05/13/2023]
Abstract
Carrot callus was centrifuged at 10 g and compared to callus growing at 1 g on agar in the presence of increasing sodium chloride concentrations. Growth after 14 days was enhanced in the centrifuged samples versus samples kept at 1 g. This effect was not found when the samples were grown on potassium chloride. At 50 mM NaCl, the calcium ionophore ionomycin was applied to centrifuged and noncentrifuged callus samples. In both experiments, the growth of callus increased with increasing ionomycin concentrations but under 10 g this increase was more enhanced. As inhibitors of calcium influx, lanthanum and gadolinium chloride were chosen in the presence of 50 mM NaCl. Both inhibitors inhibited growth at 1 g at low concentrations of around 2 microM, whereas the centrifuged samples were not or much less so inhibited. We tested an involvement of actin by application of cytochalasin D to callus grown in the presence of 50 mM NaCl. In both types of samples, growth at 1 g and growth at 10 g, cytochalasin D enhanced growth but the effect was clearly stronger at 10 g than at 1 g. As increased halotolerance was only observed in the presence of increased sodium ions, not potassium ions, and as halotolerance is known to be induced by an influx of calcium, the data suggest that a calcium influx induced by hypergravity and possibly modulated by actin caused the observed increase in halotolerance at 10 g.
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Affiliation(s)
- G F E Scherer
- Institut für Zierpflanzenbau und Gehölzwissenschaften, Universität Hannover, Hannover, Federal Republic of Germany.
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48
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Abstract
Vesicle traffic is essential for cell homeostasis, growth and development in plants, as it is in other eukaryotes, and is facilitated by a superfamily of proteins known as soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors (SNAREs). Although SNAREs are well-conserved across phylla, genomic analysis for two model angiosperm species available to date, rice and Arabidopsis, highlights common patterns of divergence from other eukaryotes. These patterns are associated with the expansion of some gene subfamilies of SNAREs, the absence of others and the appearance of new proteins that show no significant homologies to SNAREs of mammals, yeast or Drosophila. Recent findings indicate that the functions of these plant SNAREs also extend beyond the conventional 'housekeeping' activities associated with vesicle trafficking. A number of SNAREs have been implicated in environmental responses as diverse as stomata movements and gravisensing as well as sensitivity to salt and drought. These proteins are essential for signal transduction and response and, in most cases, appear also to maintain additional roles in membrane trafficking. One common theme to this added functionality lies in control of non-SNARE proteins, notably ion channels. Other examples include interactions between the SNAREs and scaffolding or other structural components within the plant cell.
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Affiliation(s)
- Jens-Uwe Sutter
- Laboratory of Plant Physiology and Biophysics, IBLS - Plant Sciences, Bower Building, University of Glasgow, Glasgow G12 8QQ, USA
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Hayashi T, Harada A, Sakai T, Takagi S. Ca2+ transient induced by extracellular changes in osmotic pressure in Arabidopsis leaves: differential involvement of cell wall-plasma membrane adhesion. PLANT, CELL & ENVIRONMENT 2006; 29:661-72. [PMID: 17080616 DOI: 10.1111/j.1365-3040.2005.01447.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We investigated the mechanism underlying the perception of extracellular changes in osmotic pressure in Vallisneria gigantea Graebner and transgenic Arabidopsis thaliana (L.) Heynh. expressing cytoplasmic aequorin. Hypertonic and hypotonic treatments of A. thaliana leaves each rapidly induced a Ca2+ transient. Both responses were essentially dependent on the presence of extracellular Ca2+ and were sensitive to Gd3+ a potential blocker of stretch-activated Ca2+ channels. Immediately after plasmolysis caused by hypertonic treatment and subsequent deplasmolysis caused by hypotonic treatment, the cells did not respond to a second hypertonic treatment and exhibited an impaired adhesion of the plasma membrane (PM) to the cell wall (CW). Recovery of the responsiveness required about 6 h. By contrast, no refractory phenomenon was observed in response to hypotonic treatment. Pretreatment with cellulase completely inhibited the Ca2+ transient induced by hypertonic treatment, but it did not affect the response to hypotonic treatment. V. gigantea mesophyll cells pretreated with cellulase exhibited an impaired adhesion of the PM to the CW. The leaf cells of multicellular plants can respond to both hypertonic and hypotonic treatments through the stretch-activated Ca2+ channels, whereas cellulase-sensitive adhesion of the PM to the CW is involved only in the response to hypertonic treatment.
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Affiliation(s)
- Teruyuki Hayashi
- Department of Biology, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
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50
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Yoon GM, Dowd PE, Gilroy S, McCubbin AG. Calcium-dependent protein kinase isoforms in Petunia have distinct functions in pollen tube growth, including regulating polarity. THE PLANT CELL 2006; 18:867-78. [PMID: 16531501 PMCID: PMC1425858 DOI: 10.1105/tpc.105.037135] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 02/07/2006] [Accepted: 02/15/2006] [Indexed: 05/07/2023]
Abstract
Calcium is a key regulator of pollen tube growth, but little is known concerning the downstream components of the signaling pathways involved. We identified two pollen-expressed calmodulin-like domain protein kinases from Petunia inflata, CALMODULIN-LIKE DOMAIN PROTEIN KINASE1 (Pi CDPK1) and Pi CDPK2. Transient overexpression or expression of catalytically modified Pi CDPK1 disrupted pollen tube growth polarity, whereas expression of Pi CDPK2 constructs inhibited tube growth but not polarity. Pi CDPK1 exhibited plasma membrane localization most likely mediated by acylation, and we present evidence that suggests this localization is critical to the biological function of this kinase. Pi CDPK2 substantially localized to as yet unidentified internal membrane compartments, and this localization was again, at least partially, mediated by acylation. In contrast with Pi CDPK1, altering the localization of Pi CDPK2 did not noticeably alter the effect of overexpressing this isoform on pollen tube growth. Ca(2+) requirements for Pi CDPK1 activation correlated closely with Ca(2+) concentrations measured in the growth zone at the pollen tube apex. Interestingly, loss of polarity associated with overexpression of Pi CDPK1 was associated with elevated cytosolic Ca(2+) throughout the bulging tube tip, suggesting that Pi CDPK1 may participate in maintaining Ca(2+) homeostasis. These results are discussed in relation to previous models for Ca(2+) regulation of pollen tube growth.
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Affiliation(s)
- Gyeong Mee Yoon
- School of Biological Sciences and Center for Reproductive Biology, Washington State University, Pullman, Washington 99164, USA
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