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Piao HL, Xuan YH, Park SH, Je BI, Park SJ, Park SH, Kim CM, Huang J, Wang GK, Kim MJ, Kang SM, Lee IJ, Kwon TR, Kim YH, Yeo US, Yi G, Son D, Han CD. OsCIPK31, a CBL-interacting protein kinase is involved in germination and seedling growth under abiotic stress conditions in rice plants. Mol Cells 2010; 30:19-27. [PMID: 20652492 DOI: 10.1007/s10059-010-0084-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 03/26/2010] [Accepted: 04/07/2010] [Indexed: 11/25/2022] Open
Abstract
Calcineurin B-like protein-interacting protein kinases (CIPKs) are a group of typical Ser/Thr protein kinases that mediate calcium signals. Extensive studies using Arabidopsis plants have demonstrated that many calcium signatures that activate CIPKs originate from abiotic stresses. However, there are few reports on the functional demonstration of CIPKs in other plants, especially in grasses. In this study, we used a loss-of-function mutation to characterize the function of the rice CIPK gene OsCIPK31. Exposure to high concentrations of NaCl or mannitol effected a rapid and transient enhancement of OsCIPK31 expression. These findings were observed only in the light. However, longer exposure to most stresses resulted in downregulation of OsCIPK31 expression in both the presence and absence of light. To determine the physiological roles of OsCIPK31 in rice plants, the sensitivity of oscipk31::Ds, which is a transposon Ds insertion mutant, to abiotic stresses was examined during germination and seedling stages. oscipk31::Ds mutants exhibited hypersensitive phenotypes to ABA, salt, mannitol, and glucose. Compared with wild-type rice plants, mutants exhibited retarded germination and slow seedling growth. In addition, oscipk31::Ds seedlings exhibited enhanced expression of several stress-responsive genes after exposure to these abiotic stresses. However, the expression of ABA metabolic genes and the endogenous levels of ABA were not altered significantly in the oscipk31::Ds mutant. This study demonstrated that rice plants use OsCIPK31 to modulate responses to abiotic stresses during the seed germination and seedling stages and to modulate the expression of stress-responsive genes.
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Affiliation(s)
- Hai-long Piao
- Division of Applied Life Science (Brain Korea 21 Program), Plant Molecular Biology and Biotechnology Research Center, Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea
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Moehninsi, Miura K, Nakajyo H, Yamada K, Hasegawa K, Shigemori H. Comparative transcriptional profiling-based identification of raphanusanin-inducible genes. BMC PLANT BIOLOGY 2010; 10:111. [PMID: 20553608 PMCID: PMC3095276 DOI: 10.1186/1471-2229-10-111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2009] [Accepted: 06/16/2010] [Indexed: 05/07/2023]
Abstract
BACKGROUND Raphanusanin (Ra) is a light-induced growth inhibitor involved in the inhibition of hypocotyl growth in response to unilateral blue-light illumination in radish seedlings. Knowledge of the roles of Ra still remains elusive. To understand the roles of Ra and its functional coupling to light signalling, we constructed the Ra-induced gene library using the Suppression Subtractive Hybridisation (SSH) technique and present a comparative investigation of gene regulation in radish seedlings in response to short-term Ra and blue-light exposure. RESULTS The predicted gene ontology (GO) term revealed that 55% of the clones in the Ra-induced gene library were associated with genes involved in common defence mechanisms, including thirty four genes homologous to Arabidopsis genes implicated in R-gene-triggered resistance in the programmed cell death (PCD) pathway. Overall, the library was enriched with transporters, hydrolases, protein kinases, and signal transducers. The transcriptome analysis revealed that, among the fifty genes from various functional categories selected from 88 independent genes of the Ra-induced library, 44 genes were up-regulated and 4 were down-regulated. The comparative analysis showed that, among the transcriptional profiles of 33 highly Ra-inducible genes, 25 ESTs were commonly regulated by different intensities and duration of blue-light irradiation. The transcriptional profiles, coupled with the transcriptional regulation of early blue light, have provided the functional roles of many genes expected to be involved in the light-mediated defence mechanism. CONCLUSIONS This study is the first comprehensive survey of transcriptional regulation in response to Ra. The results described herein suggest a link between Ra and cellular defence and light signalling, and thereby contribute to further our understanding of how Ra is involved in light-mediated mechanisms of plant defence.
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Affiliation(s)
- Moehninsi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
| | - Kenji Miura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
| | - Haruyuki Nakajyo
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
| | - Kosumi Yamada
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
| | - Koji Hasegawa
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
- KNC Laboratories Co, Ltd, Hyogo 651-2271, Japan
| | - Hideyuki Shigemori
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
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Vahisalu T, Puzõrjova I, Brosché M, Valk E, Lepiku M, Moldau H, Pechter P, Wang YS, Lindgren O, Salojärvi J, Loog M, Kangasjärvi J, Kollist H. Ozone-triggered rapid stomatal response involves the production of reactive oxygen species, and is controlled by SLAC1 and OST1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 62:442-53. [PMID: 20128877 DOI: 10.1111/j.1365-313x.2010.04159.x] [Citation(s) in RCA: 176] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The air pollutant ozone can be used as a tool to unravel in planta processes induced by reactive oxygen species (ROS). Here, we have utilized ozone to study ROS-dependent stomatal signaling. We show that the ozone-triggered rapid transient decrease (RTD) in stomatal conductance coincided with a burst of ROS in guard cells. RTD was present in 11 different Arabidopsis ecotypes, suggesting that it is a genetically robust response. To study which signaling components or ion channels were involved in RTD, we tested 44 mutants deficient in various aspects of stomatal function. This revealed that the SLAC1 protein, essential for guard cell plasma membrane S-type anion channel function, and the protein kinase OST1 were required for the ROS-induced fast stomatal closure. We showed a physical interaction between OST1 and SLAC1, and provide evidence that SLAC1 is phosphorylated by OST1. Phosphoproteomic experiments indicated that OST1 phosphorylated multiple amino acids in the N terminus of SLAC1. Using TILLING we identified three new slac1 alleles where predicted phosphosites were mutated. The lack of RTD in two of them, slac1-7 (S120F) and slac1-8 (S146F), suggested that these serine residues were important for the activation of SLAC1. Mass-spectrometry analysis combined with site-directed mutagenesis and phosphorylation assays, however, showed that only S120 was a specific phosphorylation site for OST1. The absence of the RTD in the dominant-negative mutants abi1-1 and abi2-1 also suggested a regulatory role for the protein phosphatases ABI1 and ABI2 in the ROS-induced activation of the S-type anion channel.
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Affiliation(s)
- Triin Vahisalu
- Division of Plant Biology, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), FI-00014 Helsinki, Finland
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Tominaga M, Harada A, Kinoshita T, Shimazaki KI. Biochemical Characterization of Calcineurin B-Like-Interacting Protein Kinase in Vicia Guard Cells. ACTA ACUST UNITED AC 2010; 51:408-21. [DOI: 10.1093/pcp/pcq006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Pedmale UV, Celaya RB, Liscum E. Phototropism: mechanism and outcomes. THE ARABIDOPSIS BOOK 2010; 8:e0125. [PMID: 22303252 PMCID: PMC3244944 DOI: 10.1199/tab.0125] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plants have evolved a wide variety of responses that allow them to adapt to the variable environmental conditions in which they find themselves growing. One such response is the phototropic response - the bending of a plant organ toward (stems and leaves) or away from (roots) a directional blue light source. Phototropism is one of several photoresponses of plants that afford mechanisms to alter their growth and development to changes in light intensity, quality and direction. Over recent decades much has been learned about the genetic, molecular and cell biological components involved in sensing and responding to phototropic stimuli. Many of these advances have been made through the utilization of Arabidopsis as a model for phototropic studies. Here we discuss such advances, as well as studies in other plant species where appropriate to the discussion of work in Arabidopsis.
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Affiliation(s)
- Ullas V. Pedmale
- Division of Biological Sciences and Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - R. Brandon Celaya
- Division of Biological Sciences and Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
- Department of Molecular, Cellular and Developmental Biology, University of California — Los Angeles, 3206 Life Science Bldg, 621 Charles E Young Dr, Los Angeles, CA 90095
| | - Emmanuel Liscum
- Division of Biological Sciences and Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
- Address correspondence to
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Abstract
Ca(2+) signals are a core regulator of plant cell physiology and cellular responses to the environment. The channels, pumps, and carriers that underlie Ca(2+) homeostasis provide the mechanistic basis for generation of Ca(2+) signals by regulating movement of Ca(2+) ions between subcellular compartments and between the cell and its extracellular environment. The information encoded within the Ca(2+) transients is decoded and transmitted by a toolkit of Ca(2+)-binding proteins that regulate transcription via Ca(2+)-responsive promoter elements and that regulate protein phosphorylation. Ca(2+)-signaling networks have architectural structures comparable to scale-free networks and bow tie networks in computing, and these similarities help explain such properties of Ca(2+)-signaling networks as robustness, evolvability, and the ability to process multiple signals simultaneously.
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Affiliation(s)
- Antony N Dodd
- Department of Biology, University of York, York, United Kingdom.
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Zhang Y, McCormick S. AGCVIII kinases: at the crossroads of cellular signaling. TRENDS IN PLANT SCIENCE 2009; 14:689-695. [PMID: 19818674 DOI: 10.1016/j.tplants.2009.09.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 09/10/2009] [Accepted: 09/14/2009] [Indexed: 05/28/2023]
Abstract
AGCVIII kinases regulate diverse developmental and cellular processes in plants. As putative mediators of secondary messengers, AGCVIII kinases potentially integrate developmental and environmental cues into specific cellular responses through substrate phosphorylation. Here we discuss the functionality and regulation of AGCVIII kinases. Specifically, we question the view that activities of AGCVIII kinases, like their animal counterparts, are regulated by a common regulator, 3-phosphoinositide-dependent protein kinase-1 (PDK1). Instead, increasing evidence suggests that Ca(2+) and phospholipids regulate AGCVIII kinases, by altering their activities or by affecting their subcellular localization. As AGCVIII kinases are at the crossroads of plant cellular signaling, they and the signaling networks in which they participate are keys to a better understanding of plant development and of interactions with their environment.
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Affiliation(s)
- Yan Zhang
- Plant Gene Expression Center, United States Department of Agriculture/Agricultural Research Service, and Department of Plant and Microbial Biology, University of California at Berkeley, 800 Buchanan St., Albany, CA 94710, USA
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WANG YX, WANG Z, LIU QJ, ZHAO HJ, GU YJ, QIAN XD, YUAN ZL. Relationship between cpt1 Gene and the Negative Phototropism in Rice Roots. ACTA AGRONOMICA SINICA 2009. [DOI: 10.3724/sp.j.1006.2009.01558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Vadassery J, Ranf S, Drzewiecki C, Mithöfer A, Mazars C, Scheel D, Lee J, Oelmüller R. A cell wall extract from the endophytic fungus Piriformospora indica promotes growth of Arabidopsis seedlings and induces intracellular calcium elevation in roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 59:193-206. [PMID: 19392691 DOI: 10.1111/j.1365-313x.2009.03867.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Calcium (Ca2+), as a second messenger, is crucial for signal transduction processes during many biotic interactions. We demonstrate that cellular [Ca2+] elevations are early events in the interaction between the plant growth-promoting fungus Piriformospora indica and Arabidopsis thaliana. A cell wall extract (CWE) from the fungus promotes the growth of wild-type seedlings but not of seedlings from P. indica-insensitive mutants. The extract and the fungus also induce a similar set of genes in Arabidopsis roots, among them genes with Ca2+ signalling-related functions. The CWE induces a transient cytosolic Ca2+ ([Ca2+](cyt)) elevation in the roots of Arabidopsis and tobacco (Nicotiana tabacum) plants, as well as in BY-2 suspension cultures expressing the Ca2+ bioluminescent indicator aequorin. Nuclear Ca2+ transients were also observed in tobacco BY-2 cells. The Ca2+ response was more pronounced in roots than in shoots and involved Ca2+ uptake from the extracellular space as revealed by inhibitor studies. Inhibition of the Ca2+ response by staurosporine and the refractory nature of the Ca2+ elevation suggest that a receptor may be involved. The CWE does not stimulate H2O2 production and the activation of defence gene expression, although it led to phosphorylation of mitogen-activated protein kinases (MAPKs) in a Ca2+-dependent manner. The involvement of MAPK6 in the mutualistic interaction was shown for an mpk6 line, which did not respond to P. indica. Thus, Ca2+ is likely to be an early signalling component in the mutualistic interaction between P. indica and Arabidopsis or tobacco.
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Affiliation(s)
- Jyothilakshmi Vadassery
- Friedrich-Schiller-Universität Jena, Institut für Allgemeine Botanik und Pflanzenphysiologie, Dornburger Street 159, D-07743 Jena, Germany
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60
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Anielska-Mazur A, Bernaś T, Gabryś H. In vivo reorganization of the actin cytoskeleton in leaves of Nicotiana tabacum L. transformed with plastin-GFP. Correlation with light-activated chloroplast responses. BMC PLANT BIOLOGY 2009; 9:64. [PMID: 19480655 PMCID: PMC2702303 DOI: 10.1186/1471-2229-9-64] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Accepted: 05/29/2009] [Indexed: 05/17/2023]
Abstract
BACKGROUND The actin cytoskeleton is involved in the responses of plants to environmental signals. Actin bundles play the role of tracks in chloroplast movements activated by light. Chloroplasts redistribute in response to blue light in the mesophyll cells of Nicotiana tabacum. The aim of this work was to study the relationship between chloroplast responses and the organization of actin cytoskeleton in living tobacco cells. Chloroplast movements were measured photometrically as changes in light transmission through the leaves. The actin cytoskeleton, labeled with plastin-GFP, was visualised by confocal microscopy. RESULTS The actin cytoskeleton was affected by strong blue and red light. No blue light specific actin reorganization was detected. EGTA and trifluoperazine strongly inhibited chloroplast responses and disrupted the integrity of the cytoskeleton. This disruption was reversible by Ca(2+) or Mg(2+). Additionally, the effect of trifluoperazine was reversible by light. Wortmannin, an inhibitor of phosphoinositide kinases, potently inhibited chloroplast responses but did not influence the actin cytoskeleton at the same concentration. Also this inhibition was reversed by Ca(2+) and Mg(2+). Magnesium ions were equally or more effective than Ca(2+) in restoring chloroplast motility after treatment with EGTA, trifluoperazine or wortmannin. CONCLUSION The architecture of the actin cytoskeleton in the mesophyll of tobacco is significantly modulated by strong light. This modulation does not affect the direction of chloroplast redistribution in the cell. Calcium ions have multiple functions in the mechanism of the movements. Our results suggest also that Mg(2+) is a regulatory molecule cooperating with Ca(2+) in the signaling pathway of blue light-induced tobacco chloroplast movements.
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Affiliation(s)
- Anna Anielska-Mazur
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Tytus Bernaś
- Department of Plant Anatomy and Cytology, Faculty of Biology and Environmental Protection, Silesian University, Jagiellońska 26/28, 40-032 Katowice, Poland
| | - Halina Gabryś
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
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Harada A, Shimazaki KI. Measurement of changes in cytosolic Ca2+ in Arabidopsis guard cells and mesophyll cells in response to blue light. PLANT & CELL PHYSIOLOGY 2009; 50:360-73. [PMID: 19106118 DOI: 10.1093/pcp/pcn203] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Phototropins (phot1 and phot2) are blue light (BL) receptors that mediate responses including phototropism, chloroplast movement and stomatal opening, and increased cytosolic Ca(2+). BL absorbed by phototropins activates plasma membrane H(+)-ATPase in guard cells, resulting in membrane hyperpolarization, and drives K(+) uptake and stomatal opening. However, it is unclear whether the phototropin-mediated Ca(2+) increase activates the H(+)-ATPase. Here, we determined cytosolic Ca(2+) concentrations in guard cell protoplasts (GCPs) from Arabidopsis transformed with aequorin. Cytosolic Ca(2+) increased rapidly in response to BL in GCPs from both the wild type and phot1 phot2 double mutants, but was mostly suppressed by an inhibitor of photosynthetic electron flow (DCMU). With depleted external K(+), we observed another slower Ca(2+) increase, which was phototropin- dependent. Fusicoccin, a H(+)-ATPase activator, mimicked the effect of BL. The slow Ca(2+) increase thus appears to result from membrane hyperpolarization. The slow Ca(2+) increase was suppressed by external K(+) and was restored by blockers of inward-rectifying K(+) channels, CsCl and tetraethylammonium, suggesting the preferential uptake of K(+) over Ca(2+). Such efficient K(+) uptake in response to BL was not found in mesophyll cells. Both the fast and the slow Ca(2+) increases were inhibited by Ca(2+) channel blockers (CoCl(2) and LaCl(3)) and a chelating agent (EGTA). These results indicate that the phototropin-mediated Ca(2+) increase was not observed prior to H(+)-ATPase activation in guard cells and that Ca(2+) entered guard cells via Ca(2+) channels through photosynthesis and phototropin-mediated membrane hyperpolarization.
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Affiliation(s)
- Akiko Harada
- Department of Biology, Kyushu University, Fukuoka, Japan.
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Kim MC, Chung WS, Yun DJ, Cho MJ. Calcium and calmodulin-mediated regulation of gene expression in plants. MOLECULAR PLANT 2009; 2:13-21. [PMID: 19529824 PMCID: PMC2639735 DOI: 10.1093/mp/ssn091] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Accepted: 11/21/2008] [Indexed: 05/17/2023]
Abstract
Sessile plants have developed a very delicate system to sense diverse kinds of endogenous developmental cues and exogenous environmental stimuli by using a simple Ca2+ ion. Calmodulin (CaM) is the predominant Ca2+ sensor and plays a crucial role in decoding the Ca2+ signatures into proper cellular responses in various cellular compartments in eukaryotes. A growing body of evidence points to the importance of Ca2+ and CaM in the regulation of the transcriptional process during plant responses to endogenous and exogenous stimuli. Here, we review recent progress in the identification of transcriptional regulators modulated by Ca2+ and CaM and in the assessment of their functional significance during plant signal transduction in response to biotic and abiotic stresses and developmental cues.
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Affiliation(s)
- Min Chul Kim
- Division of Applied Life Science (BK21 Program), Plant Molecular Biology and Biotechnology Research Center and Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea.
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Mazars C, Bourque S, Mithöfer A, Pugin A, Ranjeva R. Calcium homeostasis in plant cell nuclei. THE NEW PHYTOLOGIST 2009; 181:261-274. [PMID: 19130634 DOI: 10.1111/j.1469-8137.2008.02680.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In plant cells, calcium-based signaling pathways are involved in a large array of biological processes, including cell division, polarity, growth, development and adaptation to changing biotic and abiotic environmental conditions. Free calcium changes are known to proceed in a nonstereotypical manner and produce a specific signature, which mirrors the nature, strength and frequency of a stimulus. The temporal aspects of calcium signatures are well documented, but their vectorial aspects also have a profound influence on biological output. Here, we will focus on the regulation of calcium homeostasis in the nucleus. We will discuss data and present hypotheses suggesting that, while interacting with other organelles, the nucleus has the potential to generate and regulate calcium signals on its own.
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Affiliation(s)
- Christian Mazars
- UMR CNRS 5546/Université de Toulouse, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, BP 42617 Auzeville, 31326 Castanet-Tolosan cédex, France;UMR INRA 1088/CNRS 5184/Université de Bourgogne Plante-Microbe-Environnement, 17 Rue Sully, BP 86510, 21065 Dijon cédex, France;Max Planck Institute for Chemical Ecology, Department Bioorganic Chemistry, Hans-Knöll-Str. 8, 07745 Jena, Germany;GDR CNRS Calcium et Régulation des Gènes, 118 route de Narbonne, 31062 Toulouse cédex, France
| | - Stéphane Bourque
- UMR CNRS 5546/Université de Toulouse, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, BP 42617 Auzeville, 31326 Castanet-Tolosan cédex, France;UMR INRA 1088/CNRS 5184/Université de Bourgogne Plante-Microbe-Environnement, 17 Rue Sully, BP 86510, 21065 Dijon cédex, France;Max Planck Institute for Chemical Ecology, Department Bioorganic Chemistry, Hans-Knöll-Str. 8, 07745 Jena, Germany;GDR CNRS Calcium et Régulation des Gènes, 118 route de Narbonne, 31062 Toulouse cédex, France
| | - Axel Mithöfer
- UMR CNRS 5546/Université de Toulouse, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, BP 42617 Auzeville, 31326 Castanet-Tolosan cédex, France;UMR INRA 1088/CNRS 5184/Université de Bourgogne Plante-Microbe-Environnement, 17 Rue Sully, BP 86510, 21065 Dijon cédex, France;Max Planck Institute for Chemical Ecology, Department Bioorganic Chemistry, Hans-Knöll-Str. 8, 07745 Jena, Germany;GDR CNRS Calcium et Régulation des Gènes, 118 route de Narbonne, 31062 Toulouse cédex, France
| | - Alain Pugin
- UMR CNRS 5546/Université de Toulouse, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, BP 42617 Auzeville, 31326 Castanet-Tolosan cédex, France;UMR INRA 1088/CNRS 5184/Université de Bourgogne Plante-Microbe-Environnement, 17 Rue Sully, BP 86510, 21065 Dijon cédex, France;Max Planck Institute for Chemical Ecology, Department Bioorganic Chemistry, Hans-Knöll-Str. 8, 07745 Jena, Germany;GDR CNRS Calcium et Régulation des Gènes, 118 route de Narbonne, 31062 Toulouse cédex, France
| | - Raoul Ranjeva
- UMR CNRS 5546/Université de Toulouse, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, BP 42617 Auzeville, 31326 Castanet-Tolosan cédex, France;UMR INRA 1088/CNRS 5184/Université de Bourgogne Plante-Microbe-Environnement, 17 Rue Sully, BP 86510, 21065 Dijon cédex, France;Max Planck Institute for Chemical Ecology, Department Bioorganic Chemistry, Hans-Knöll-Str. 8, 07745 Jena, Germany;GDR CNRS Calcium et Régulation des Gènes, 118 route de Narbonne, 31062 Toulouse cédex, France
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Kwak JM, Mäser P, Schroeder JI. The Clickable Guard Cell, Version II: Interactive Model of Guard Cell Signal Transduction Mechanisms and Pathways. THE ARABIDOPSIS BOOK 2008; 6:e0114. [PMID: 22303239 PMCID: PMC3243356 DOI: 10.1199/tab.0114] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO(2) influx from the atmosphere into leaves for photosynthetic carbon fixation. Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere. Signal transduction mechanisms in guard cells integrate a multitude of different stimuli to modulate stomatal apertures. Stomata open in response to light. Stomata close in response to drought stress, elevated CO(2), ozone and low humidity. In response to drought, plants synthesize the hormone abscisic acid (ABA) that triggers closing of stomatal pores. Guard cells have become a highly developed model system for dissecting signal transduction mechanisms in plants and for elucidating how individual signaling mechanisms can interact within a network in a single cell. Many new findings have been made in the last few years. This chapter is an update of an electronic interactive chapter in the previous edition of The Arabidopsis Book (Mäser et al. 2003). Here we focus on mechanisms for which genes and mutations have been characterized, including signaling components for which there is substantial signaling, biochemical and genetic evidence. Ion channels have been shown to represent targets of early signal transduction mechanisms and provide functional signaling and quantitative analysis points to determine where and how mutations affect branches within the guard cell signaling network. Although a substantial number of genes and proteins that function in guard cell signaling have been identified in recent years, there are many more left to be identified and the protein-protein interactions within this network will be an important subject of future research. A fully interactive clickable electronic version of this publication can be accessed at the following web site: http://www-biology.ucsd.edu/labs/schroeder/clickablegc2/. The interactive clickable version includes the following features: Figure 1. Model for the roles of ion channels in ABA signaling.Figure 2. Blue light signaling pathways in guard cells.Figure 3. ABA signaling pathways in guard cells.Figure 1 is linked to explanations that appear upon mouse-over. Figure 2 and Figure 3 are clickable and linked to info boxes, which in turn are linked to TAIR, to relevant abstracts in PubMed, and to updated background explanations from Schroeder et al (2001), used with permission of Annual Reviews of Plant Biology.
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Affiliation(s)
- June M. Kwak
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| | - Pascal Mäser
- Institute of Cell Biology, University of Berne, CH-3012 Bern, Switzerland
| | - Julian I. Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section and Center for Molecular Genetics, University of California, San Diego, La Jolla, California 92093-0116
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Bogacki P, Oldach KH, Williams KJ. Expression profiling and mapping of defence response genes associated with the barley-Pyrenophora teres incompatible interaction. MOLECULAR PLANT PATHOLOGY 2008; 9:645-60. [PMID: 19018994 PMCID: PMC6640259 DOI: 10.1111/j.1364-3703.2008.00485.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Barley net- and spot-form of net blotch disease are caused by two formae of the hemibiotrophic fungus Pyrenophora teres (P. t. f. teres and P. t. f. maculata). In the present study, suppression subtractive hybridization (SSH) was used in combination with quantitative real-time reverse transcriptase PCR to identify and profile the expression of defence response (DR) genes in the early stages of both barley-P. teres incompatible and compatible interactions. From a pool of 307 unique gene transcripts identified by SSH, 45 candidate DR genes were selected for temporal expression profiling in infected leaf epidermis. Differential expression profiles were observed for 28 of the selected candidates, which were grouped into clusters depending on their expression profiles within the first 48 h after inoculation. The expression profiles characteristic of each gene cluster were very similar in both barley-P. t. f. teres and barley-P. t. f. maculata interactions, indicating that resistance to both pathogens could be mediated by induction of the same group of DR genes. Chromosomal map locations for 21 DR genes were identified using four doubled-haploid mapping populations. The mapped DR genes were distributed across all seven barley chromosomes, with at least one gene mapping to within 15 cM of another on chromosomes 1H, 2H, 5H and 7H. Additionally, some DR genes appeared to co-localize with loci harbouring known resistance genes or quantitative trait loci for net blotch resistance on chromosomes 6H and 7H, as well as loci associated with resistance to other barley diseases. The DR genes are discussed with respect to their map locations and potential functional role in contributing to net blotch disease resistance.
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Affiliation(s)
- P Bogacki
- Molecular Plant Breeding CRC, South Australian Research and Development Institute, GPO Box 397, Adelaide, SA 5001, Australia.
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Haruta M, Monshausen G, Gilroy S, Sussman MR. A cytoplasmic Ca2+ functional assay for identifying and purifying endogenous cell signaling peptides in Arabidopsis seedlings: identification of AtRALF1 peptide. Biochemistry 2008; 47:6311-21. [PMID: 18494498 DOI: 10.1021/bi8001488] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Transient increases in the cytoplasmic Ca(2+) concentration are key events that initiate many cellular signaling pathways in response to developmental and environmental cues in plants; however, only a few extracellular mediators regulating cytoplasmic Ca(2+) singling are known to date. To identify endogenous cell signaling peptides regulating cytoplasmic Ca(2+) signaling, Arabidopsis seedlings expressing aequorin were used for an in vivo luminescence assay for Ca(2+) changes. These seedlings were challenged with fractions derived from plant extracts. Multiple heat-stable, protease-sensitive peaks of calcium elevating activity were observed after fractionation of these extracts by high-performance liquid chromatography. Tandem mass spectrometry identified the predominant active molecule isolated by a series of such chromatographic separations as a 49-amino acid polypeptide, AtRALF1 (the rapid alkalinization factor protein family). Within 40 s of treatment with nanomolar concentrations of the natural or synthetic version of the peptides, the cytoplasmic Ca(2+) level increased and reached its maximum. Prior treatment with a Ca(2+) chelator or inhibitor of IP 3-dependent signaling partially suppressed the AtRALF1-induced Ca(2+) concentration increase, indicating the likely involvement of Ca(2+) influx across the plasma membrane as well as release of Ca(2+) from intracellular reserves. Ca(2+) imaging using seedlings expressing the FRET-based Ca(2+) sensor yellow cameleon (YC) 3.6 showed that AtRALF1 could induce an elevation in Ca(2+) concentration in the surface cells of the root consistent with the very rapid effects of addition of AtRALF1 on Ca(2+) levels as reported by aequorin. Our data support a model in which the RALF peptide mediates Ca(2+)-dependent signaling events through a cell surface receptor, where it may play a role in eliciting events linked to stress responses or the modulation of growth.
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Affiliation(s)
- Miyoshi Haruta
- UW Biotechnology Center, University of Wisconsin, Madison, Wisconsin 53706, USA
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68
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Chen X, Lin WH, Wang Y, Luan S, Xue HW. An inositol polyphosphate 5-phosphatase functions in PHOTOTROPIN1 signaling in Arabidopis by altering cytosolic Ca2+. THE PLANT CELL 2008; 20:353-66. [PMID: 18252844 PMCID: PMC2276452 DOI: 10.1105/tpc.107.052670] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2007] [Revised: 11/22/2007] [Accepted: 01/21/2008] [Indexed: 05/18/2023]
Abstract
Inositol polyphosphate 5-phosphatase (5PTase) is a key enzyme in the phosphatidylinositol metabolic pathway, which plays critical roles in a number of cellular processes in plants. Our previous work implicated the role of 5PTase13, which encodes a WD40-containing type II 5PTase, in hormone-mediated cotyledon vein development. Here, we show that 5PTase13 is also involved in blue light responses in Arabidopsis thaliana. Compared with that in darkness, the expression of 5PTase13 was suppressed by blue light irradiation, and disruption of the gene resulted in shortened hypocotyls and expanded cotyledons. Genetic analysis showed that 5PTase13 acted independently from CRYPTOCHROME1 and CONSTITUTIVE PHOTOMORPHOGENIC1 but interacted functionally with PHOTOTROPIN1 (PHOT1). The expression level of 5PTase13 was significantly enhanced in phot1 single or phot1 phot2 double mutants under blue light, and suppression of 5PTase13 expression rescued the elongated hypocotyls in the phot1 or phot1 phot2 mutants. Further analysis showed that the blue light-induced elevation of cytosolic Ca2+ was inhibited in the phot1 mutant but enhanced in the 5pt13 mutant, suggesting that 5PTase13 antagonizes PHOT1-mediated effects on calcium signaling under blue light.
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Affiliation(s)
- Xu Chen
- Shanghai Institutes for Biological Science-University of California Berkeley Center of Molecular Life Sciences, Chinese Academy of Sciences, 20032 Shanghai, China
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69
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Xiong TC, Coursol S, Grat S, Ranjeva R, Mazars C. Sphingolipid metabolites selectively elicit increases in nuclear calcium concentration in cell suspension cultures and in isolated nuclei of tobacco. Cell Calcium 2008; 43:29-37. [PMID: 17570488 DOI: 10.1016/j.ceca.2007.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 02/07/2007] [Accepted: 02/13/2007] [Indexed: 11/29/2022]
Abstract
Sphingolipids are known to interfere with calcium-based signalling pathways. Here we report that these compounds modulate nuclear calcium signalling in tobacco BY-2 cells. Nuclear protein kinase activity phosphorylated endogenous sphingoid long-chain bases (LCBs), suggesting that LCBs are actively metabolized in the nucleus of tobacco BY-2 cells. The Delta4-unsaturated LCB D-erythro-sphingosine and the saturated LCB D-ribo-phytosphingosine elicited increases in free calcium in the nucleus in a dose-dependent and structure-related manner. However, neither sphingosine-1-phosphate nor C2-ceramide was able to stimulate nuclear calcium changes. N-,N-Dimethyl-D-erythro-sphingosine, a structural analogue of D-erythro-sphingosine, was the most efficient LCB so far tested in eliciting nuclear calcium changes both in intact tobacco BY-2 cells and in isolated nuclei. TRP channel inhibitors prevent the effect of DMS, suggesting that LCBs may activate TRP-like channels located on the inner nuclear membrane Collectively, the obtained data show that nuclei respond to LCBs on their own independently of the cytosolic compartment.
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Affiliation(s)
- Tou Cheu Xiong
- UMR CNRS/UPS 5546, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, 24 Chemin de Borde Rouge, BP 42617 Auzeville, 31326 Castanet-Tolosan, France
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70
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71
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Furuichi T, Kawano T, Tatsumi H, Sokabe M. Roles of Ion Channels in the Environmental Responses of Plants. SENSING WITH ION CHANNELS 2008. [DOI: 10.1007/978-3-540-72739-2_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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72
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Koselski M, Trebacz K, Dziubinska H, Krol E. Light- and dark-induced action potentials in Physcomitrella patens. PLANT SIGNALING & BEHAVIOR 2008; 3:13-8. [PMID: 19516976 PMCID: PMC2633949 DOI: 10.4161/psb.3.1.4884] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Accepted: 08/15/2007] [Indexed: 05/07/2023]
Abstract
Glass microelectrodes were inserted into Physcomitrella patens gametophyte leaves and action potentials (APs) were recorded in response to sudden illumination as well as after darkening, i.e., when the dark-induced membrane depolarization crossed a threshold. Application of 5 mM La(3+) (a calcium channel inhibitor), 10 mM TEA(+) (a potassium channel inhibitor) and increased free Ca(2+) resulted in a loss of excitability. Lack of Ca(2+) in the external medium did not prevent APs from occurring. It was concluded that during light- dark-induced excitation of Physcomitrella patens, APs might rely upon calcium influxes from the intracellular compartments. APs were not blocked by the proton pump inhibitors (DES, DCCD), although the resting potential (RP) diminished significantly.
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Affiliation(s)
- Mateusz Koselski
- Department of Biophysics; Institute of Biology; Maria Curie-Sklodowska University; Lublin, Poland
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73
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Wan YL, Eisinger W, Ehrhardt D, Kubitscheck U, Baluska F, Briggs W. The subcellular localization and blue-light-induced movement of phototropin 1-GFP in etiolated seedlings of Arabidopsis thaliana. MOLECULAR PLANT 2008; 1:103-117. [PMID: 20031918 DOI: 10.1093/mp/ssm011] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Phototropin 1 (phot1) is a photoreceptor for phototropism, chloroplast movement, stomatal opening, leaf expansion, and solar tracking in response to blue light. Following earlier work with PHOT1::GFP (Sakamoto and Briggs, 2002), we investigated the pattern of cellular and subcellular localization of phot1 in 3- 4-d-old etiolated seedlings of Arabidopsis thalinana. As expressed from native upstream sequences, the PHOT1::GFP fusion protein is expressed strongly in the abaxial tissues of the cotyledons and in the elongating regions of the hypocotyl. It is moderately expressed in the shoot/root transition zone and in cells near the root apex. A fluorescence signal is undetectable in the root epidermis, root cap, and root apical meristem itself. The plasma membranes of mesophyll cells near the cotyledon margin appear labeled uniformly but cross-walls created by recent cell divisions are more strongly labeled. The pattern of labeling of individual cell types varies with cell type and developmental stage. Blue-light treatment causes PHOT1::GFP, initially relatively evenly distributed at the plasma membrane, to become reorganized into a distinct mosaic with strongly labeled punctate areas and other areas completely devoid of fluorescence--a phenomenon best observed in cortical cells in the hypocotyl elongation region. Concomitant with or following this reorganization, PHOT1::GFP moves into the cytoplasm in all cell types investigated except for guard cells. It disappears from the cytoplasm by an unidentified mechanism after several hours in darkness. Neither its appearance in the cytoplasm nor its eventual disappearance in darkness is prevented by the translation inhibitor cycloheximide, although the latter process is retarded. We hypothesize that blue-light-induced phot1 re-localization modulates blue-light-activated signal transduction.
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Affiliation(s)
- Ying-Lang Wan
- Dept Plant Cell Biology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany
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74
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Suetsugu N, Wada M. Chloroplast photorelocation movement mediated by phototropin family proteins in green plants. Biol Chem 2007; 388:927-35. [PMID: 17696776 DOI: 10.1515/bc.2007.118] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Chloroplasts gather in areas irradiated with weak light to maximize photosynthesis (the accumulation response). They move away from areas irradiated with strong light to minimize damage of the photosynthetic apparatus (the avoidance response). The processes underlying these chloroplast movements can be divided into three parts: photoperception, signal transduction, and chloroplast movement. Photoreceptors for chloroplast movement have been identified recently in various plant species. A blue light receptor phototropin (phot) mediates chloroplast photorelocation movement in the seed plant Arabidopsis thaliana, the fern Adiantum capillus-veneris, the moss Physcomitrella patens and possibly the green alga Mougeotia scalaris. A chimeric photoreceptor between phytochrome and phototropin, neochrome (neo), was found in some advanced ferns and in the green alga M. scalaris. While the mechanism of chloroplast movement is not well understood, it is known that actin filaments play an important role in this process. To understand the molecular mechanisms associated with chloroplast movement, several mutants were isolated in A. thaliana (jac1 and chup1) and the corresponding genes were cloned. In this review, recent progress in photoreceptor research into chloroplast movement in various plant species and the possible factors functioning in signal transduction or the regulation of actin filaments identified in A. thaliana is discussed.
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Affiliation(s)
- Noriyuki Suetsugu
- Division of Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
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75
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Xu X, Hotta CT, Dodd AN, Love J, Sharrock R, Lee YW, Xie Q, Johnson CH, Webb AAR. Distinct light and clock modulation of cytosolic free Ca2+ oscillations and rhythmic CHLOROPHYLL A/B BINDING PROTEIN2 promoter activity in Arabidopsis. THE PLANT CELL 2007; 19:3474-90. [PMID: 17982000 PMCID: PMC2174886 DOI: 10.1105/tpc.106.046011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 09/30/2007] [Accepted: 10/15/2007] [Indexed: 05/17/2023]
Abstract
Plants have circadian oscillations in the concentration of cytosolic free calcium ([Ca(2+)](cyt)). To dissect the circadian Ca(2+)-signaling network, we monitored circadian [Ca(2+)](cyt) oscillations under various light/dark conditions (including different spectra) in Arabidopsis thaliana wild type and photoreceptor and circadian clock mutants. Both red and blue light regulate circadian oscillations of [Ca(2+)](cyt). Red light signaling is mediated by PHYTOCHROME B (PHYB). Blue light signaling occurs through the redundant action of CRYPTOCHROME1 (CRY1) and CRY2. Blue light also increases the basal level of [Ca(2+)](cyt), and this response requires PHYB, CRY1, and CRY2. Light input into the oscillator controlling [Ca(2+)](cyt) rhythms is gated by EARLY FLOWERING3. Signals generated in the dark also regulate the circadian behavior of [Ca(2+)](cyt). Oscillations of [Ca(2+)](cyt) and CHLOROPHYLL A/B BINDING PROTEIN2 (CAB2) promoter activity are dependent on the rhythmic expression of LATE ELONGATED HYPOCOTYL and CIRCADIAN CLOCK-ASSOCIATED1, but [Ca(2+)](cyt) and CAB2 promoter activity are uncoupled in the timing of cab1 (toc1-1) mutant but not in toc1-2. We suggest that the circadian oscillations of [Ca(2+)](cyt) and CAB2 promoter activity are regulated by distinct oscillators with similar components that are used in a different manner and that these oscillators may be located in different cell types in Arabidopsis.
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Affiliation(s)
- Xiaodong Xu
- Department of Biological Sciences, Vanderbilt University, Nashville, Tenessee 37235, USA
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76
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Hardtke CS, Dorcey E, Osmont KS, Sibout R. Phytohormone collaboration: zooming in on auxin-brassinosteroid interactions. Trends Cell Biol 2007; 17:485-92. [PMID: 17904848 DOI: 10.1016/j.tcb.2007.08.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 08/13/2007] [Accepted: 08/13/2007] [Indexed: 12/01/2022]
Abstract
Similar to animal hormones, classic plant hormones are small organic molecules that regulate physiological and developmental processes. In development, this often involves the regulation of growth through the control of cell size or division. The plant hormones auxin and brassinosteroid modulate both cell expansion and proliferation and are known for their overlapping activities in physiological assays. Recent molecular genetic analyses in the model plant Arabidopsis suggest that this reflects interdependent and often synergistic action of the two hormone pathways. Such pathway interactions probably occur through the combinatorial regulation of common target genes by auxin- and brassinosteroid-controlled transcription factors. Moreover, auxin and brassinosteroid signaling and biosynthesis and auxin transport might be linked by an emerging upstream connection involving calcium-calmodulin and phosphoinositide signaling.
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Affiliation(s)
- Christian S Hardtke
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland.
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77
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Harada A, Shimazaki KI. Phototropins and blue light-dependent calcium signaling in higher plants. Photochem Photobiol 2007; 83:102-11. [PMID: 16906793 DOI: 10.1562/2006-03-08-ir-837] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plants have several kinds of photoreceptors, which regulate growth and development. Recent investigations using Arabidopsis thaliana revealed that the newly found blue light receptor phototropins mediate phototropism, chloroplast relocation, stomatal opening, rapid inhibition of hypocotyl elongation and leaf expansion. Several physiological studies suggest that one of the intermediates in phototropin signaling is cytosolic Ca2+. Studies using phototropin mutants have demonstrated that phototropins induce an increase in cytosolic Ca2+ concentration. However, the function of Ca2+ in the phototropin-mediated signaling process remains largely unknown. This review presents findings about phototropin-mediated calcium mobilization and the involvement of calcium in blue light-dependent plant responses.
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Affiliation(s)
- Akiko Harada
- Department of Biology, Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Fukuoka, Japan.
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78
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Suetsugu N, Wada M. Phytochrome-dependent photomovement responses mediated by phototropin family proteins in cryptogam plants. Photochem Photobiol 2007; 83:87-93. [PMID: 16542113 DOI: 10.1562/2006-02-27-ir-817] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In this review, we describe the regulation of photomovement responses by phototropin and phytochrome photoreceptors. The blue light receptor phototropin mediates various photomovement responses such as phototropism, chloroplast movement and stomatal opening. In cryptogamic plants including ferns, mosses and green alga, red as well as blue light mediates phototropism and chloroplast movement. The red/far-red light reversibility suggests the involvement of phytochrome in these responses. Thereby, plant growth is presumably promoted by coordinating these photomovements to capture efficiently light for photosynthesis.
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Affiliation(s)
- Noriyuki Suetsugu
- Division of Photobiology, National Institute for Basic Biology, Okazaki, Japan
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79
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Liscum E, Stowe-Evans EL. Phototropism: A “Simple” Physiological Response Modulated by Multiple Interacting Photosensory-response Pathways ¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2000)0720273pasprm2.0.co2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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80
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81
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Shimazaki KI, Doi M, Assmann SM, Kinoshita T. Light regulation of stomatal movement. ANNUAL REVIEW OF PLANT BIOLOGY 2007; 58:219-47. [PMID: 17209798 DOI: 10.1146/annurev.arplant.57.032905.105434] [Citation(s) in RCA: 462] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Stomatal pores, each surrounded by a pair of guard cells, regulate CO2 uptake and water loss from leaves. Stomatal opening is driven by the accumulation of K+ salts and sugars in guard cells, which is mediated by electrogenic proton pumps in the plasma membrane and/or metabolic activity. Opening responses are achieved by coordination of light signaling, light-energy conversion, membrane ion transport, and metabolic activity in guard cells. In this review, we focus on recent progress in blue- and red-light-dependent stomatal opening. Because the blue-light response of stomata appears to be strongly affected by red light, we discuss underlying mechanisms in the interaction between blue-light signaling and guard cell chloroplasts.
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Affiliation(s)
- Ken-ichiro Shimazaki
- Department of Biology, Faculty of Science, Kyushu University, Ropponmatsu, Fukuoka 810-8560, Japan.
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82
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Chloroplast Movements in Response to Environmental Signals. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2007. [DOI: 10.1007/978-1-4020-4061-0_26] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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83
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Abstract
Phototropins are blue-light receptors controlling a range of responses that serve to optimize the photosynthetic efficiency of plants. These include phototropism, light-induced stomatal opening, and chloroplast movements in response to changes in light intensity. Since the isolation of the Arabidopsis PHOT1 gene in 1997, phototropins have been identified in ferns and mosses where their physiological functions appear to be conserved. Arabidopsis contains two phototropins, phot1 and phot2, that exhibit overlapping functions in addition to having unique physiological roles. Phototropins are light-activated serine/threonine protein kinases. Light sensing by the phototropins is mediated by a repeated motif at the N-terminal region of the protein known as the LOV domain. Photoexcitation of the LOV domain results in receptor autophosphorylation and an initiation of phototropin signaling. Here we summarize the photochemical and biochemical events underlying phototropin activation in addition to the current knowledge of the molecular mechanisms associated with photoreceptor signaling.
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Affiliation(s)
- John M Christie
- Plant Science Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
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84
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Johnson CH, Shingles R, Ettinger WF. Regulation and Role of Calcium Fluxes in the Chloroplast. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2007. [DOI: 10.1007/978-1-4020-4061-0_20] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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85
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Carpaneto A, Ivashikina N, Levchenko V, Krol E, Jeworutzki E, Zhu JK, Hedrich R. Cold transiently activates calcium-permeable channels in Arabidopsis mesophyll cells. PLANT PHYSIOLOGY 2007; 143:487-94. [PMID: 17114272 PMCID: PMC1761956 DOI: 10.1104/pp.106.090928] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Accepted: 11/07/2006] [Indexed: 05/12/2023]
Abstract
Living organisms are capable of discriminating thermal stimuli from noxious cold to noxious heat. For more than 30 years, it has been known that plant cells respond to cold with a large and transient depolarization. Recently, using transgenic Arabidopsis (Arabidopsis thaliana) expressing the calcium-sensitive protein aequorin, an increase in cytosolic calcium following cold treatment was observed. Applying the patch-clamp technique to Arabidopsis mesophyll protoplasts, we could identify a transient plasma membrane conductance induced by rapid cooling. This cold-induced transient conductance was characterized as an outward rectifying 33 pS nonselective cation channel. The permeability ratio between calcium and cesium was 0.7, pointing to a permeation pore >3.34 A (ø of cesium). Our experiments thus provide direct evidence for the predicted but not yet measured cold-activated calcium-permeable channel in plants.
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Affiliation(s)
- Armando Carpaneto
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute of Biosciences, Wurzburg University, 97082 Wurzburg, Germany
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86
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Xiong TC, Bourque S, Lecourieux D, Amelot N, Grat S, Brière C, Mazars C, Pugin A, Ranjeva R. Calcium signaling in plant cell organelles delimited by a double membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1209-15. [PMID: 17052770 DOI: 10.1016/j.bbamcr.2006.09.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 09/13/2006] [Accepted: 09/15/2006] [Indexed: 01/07/2023]
Abstract
Increases in the concentration of free calcium in the cytosol are one of the general events that relay an external stimulus to the internal cellular machinery and allow eukaryotic organisms, including plants, to mount a specific biological response. Different lines of evidence have shown that other intracellular organelles contribute to the regulation of free calcium homeostasis in the cytosol. The vacuoles, the endoplasmic reticulum and the cell wall constitute storage compartments for mobilizable calcium. In contrast, the role of organelles surrounded by a double membrane (e.g. mitochondria, chloroplasts and nuclei) is more complex. Here, we review experimental data showing that these organelles harbor calcium-dependent biological processes. Mitochondria, chloroplasts as well as nuclei are equipped to generate calcium signal on their own. Changes in free calcium in a given organelle may also favor the relocalization of proteins and regulatory components and therefore have a profound influence on the integrated functioning of the cell. Studying, in time and space, the dynamics of different components of calcium signaling pathway will certainly give clues to understand the extraordinary flexibility of plants to respond to stimuli and mount adaptive responses. The availability of technical and biological resources should allow breaking new grounds by unveiling the contribution of signaling networks in integrative plant biology.
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Affiliation(s)
- Tou-Cheu Xiong
- UMR CNRS/Université Paul Sabatier 5546, Surfaces Cellulaires et Signalisation chez les Végétaux, Pôle de Biotechnologie Végétale, 24 chemin de Borde Rouge, Auzeville BP42617, 31326 Castanet-Tolosan, France
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87
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Im CS, Eberhard S, Huang K, Beck CF, Grossman AR. Phototropin involvement in the expression of genes encoding chlorophyll and carotenoid biosynthesis enzymes and LHC apoproteins in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 48:1-16. [PMID: 16972865 DOI: 10.1111/j.1365-313x.2006.02852.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Phototropin (PHOT) is a photoreceptor involved in a variety of blue-light-elicited physiological processes including phototropism, chloroplast movement and stomatal opening in plants. The work presented here tests whether PHOT is involved in expression of light-regulated genes in Chlamydomonas reinhardtii. When C. reinhardtii was transferred from the dark to very low-fluence rate white light, there was a substantial increase in the level of transcripts encoding glutamate-1-semialdehyde aminotransferase (GSAT), phytoene desaturase (PDS) and light-harvesting polypeptides (e.g. LHCBM6). Increased levels of these transcripts were also elicited by low-intensity blue light, and this blue-light stimulation was suppressed in three different RNAi strains that synthesize low levels of PHOT. The levels of GSAT and LHCBM6 transcripts also increased following exposure of algal cells to low-intensity red light (RL). The red-light-dependent increase in transcript abundance was not affected by the electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea, implying that the influence of RL on transcript accumulation was not controlled by cytoplasmic redox conditions, and that a red-light photoreceptor(s) may be involved in regulating the levels of transcripts from specific photosynthesis-related genes in C. reinhardtii. Interestingly, elevated GSAT and LHCBM6 transcript levels in RL were significantly reduced in the PHOT RNAi strains, which raises the possibility of co-action between blue and RL signaling pathways. Microarray experiments indicated that the levels of several transcripts for photosystem (PS) I and II polypeptides were also modulated by PHOT. These data suggest that, in C. reinhardtii, (i) PHOT is involved in blue-light-mediated changes in transcript accumulation, (ii) synchronization of the synthesis of chlorophylls (Chl), carotenoids, Chl-binding proteins and other components of the photosynthetic apparatus is achieved, at least in part, through PHOT-mediated signaling, and (iii) a red-light photoreceptor can also influence levels of certain transcripts associated with photosynthetic function, although its action requires normal levels of PHOT.
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Affiliation(s)
- Chung-Soon Im
- Department of Plant Biology, Carnegie Institution, Stanford, CA 94306, USA.
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88
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Hedrich R, Marten I. 30-year progress of membrane transport in plants. PLANTA 2006; 224:725-39. [PMID: 16835760 DOI: 10.1007/s00425-006-0341-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Accepted: 03/18/2006] [Indexed: 05/10/2023]
Abstract
In the past 30 years enormous progress was made in plant membrane biology and transport physiology, a fact reflected in the appearance of textbooks. The first book dedicated to 'Membrane Transport in Plants' was published on the occasion of the 'International Workshop on Membrane Transport in Plants' held at the Nuclear Research Center, Jülich, Germany [Zimmermann and Dainty (eds) 1974] and was followed in 1976 by a related volume 'Transport in plants II' in the 'Encyclopedia of plant physiology' [Lüttge and Pitman (eds) 1976]. A broad spectrum of topics including thermodynamics of transport processes, water relations, primary reactions of photosynthesis, as well as more conventional aspects of membrane transport was presented. The aim of the editors of the first book was to bring advanced thermodynamical concepts to the attention of biologists and to show physical chemists and biophysicist what the more complex biological systems were like. To bundle known data on membrane transport in plants and relevant fields for mutual understanding, interdisciplinary research and clarification of problems were considered highly important for further progress in this scientific area of plant physiology. The present review will critically evaluate the progress in research in membrane transport in plants that was achieved during the past. How did 'Membrane Transport in Plants' progress within the 30 years between the publication of the first book about this topic (Zimmermann and Dainty 1974), a recent one with the same title (Blatt 2004), and today?
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Affiliation(s)
- Rainer Hedrich
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Bioscience, University of Wuerzburg, Julius-von-Sachs-Platz 2, 97082 Wuerzburg, Germany.
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89
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Foley RC, Sappl PG, Perl-Treves R, Millar AH, Singh KB. Desensitization of GSTF8 induction by a prior chemical treatment is long lasting and operates in a tissue-dependent manner. PLANT PHYSIOLOGY 2006; 142:245-53. [PMID: 16829588 PMCID: PMC1557611 DOI: 10.1104/pp.106.079509] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The Arabidopsis (Arabidopsis thaliana) GSTF8 gene is a member of the glutathione S-transferase (GST) family whose expression is induced by defense signals, certain chemical stresses, and some pathogens. Here, we have used transgenic plants and an in vivo imaging system to demonstrate that GSTF8 expression is subject to a distinct desensitization phenomenon because prior chemical treatment significantly reduces reactivation of the GSTF8 promoter by hydrogen peroxide, auxin, and salicylic acid. A GSTF8 null line had similar desensitization properties to wild type, demonstrating that GSTF8 protein levels are not responsible for desensitization. The resulting refractory period is unusually long lasting, with full recovery taking 4 d. Expression of the GSTF8 promoter following a second treatment occurred predominantly in newly formed tissue at the root tip, suggesting that desensitization is lost upon cell division. Expression of the endogenous GSTF8 gene and another GST gene, GSTF6, is also desensitized following treatment with hydrogen peroxide. The desensitization phenomenon can be activated by a very low concentration of inducer that is not sufficient to activate the GSTF8 promoter. These results demonstrate that activation of the GSTF8 promoter is not essential for eliciting desensitization. A key promoter sequence within the GSTF8 gene, the ocs element, is also affected by desensitization. Treatment with a phosphatase inhibitor prevents desensitization of GSTF8 expression and ocs element activity, suggesting that dephosphorylation of one or more proteins is required for desensitization to occur.
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Affiliation(s)
- Rhonda C Foley
- Commonwealth Scientific and Industrial Research Organization Plant Industry, Centre for Environmental and Life Sciences, Wembley, Western Australia 6913, Australia
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90
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Sun QP, Guo Y, Sun Y, Sun DY, Wang XJ. Influx of extracellular Ca2+ involved in jasmonic-acid-induced elevation of [Ca2+]cyt and JR1 expression in Arabidopsis thaliana. JOURNAL OF PLANT RESEARCH 2006; 119:343-50. [PMID: 16708291 DOI: 10.1007/s10265-006-0279-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2006] [Accepted: 03/07/2006] [Indexed: 05/09/2023]
Abstract
The changes in cytosolic Ca2+ levels play important roles in the signal transduction pathways of many environmental and developmental stimuli in plants and animals. We demonstrated that the increase in cytosolic free Ca2+ concentration ([Ca2+]cyt) of Arabidopsis thaliana leaf cells was induced by exogenous application of jasmonic acid (JA). The elevation of [Ca2+]cyt was detected within 1 min after JA treatment by the fluorescence intensity using laser scanning confocal microscopy, and the elevated level of fluorescence was maintained during measuring time. With pretreatment of nifedipine (Nif), a nonpermeable L-type channel blocker, the fluorescence of [Ca2+]cyt induced by JA was inhibited in a dose-dependent manner. In contrast, verapamil, another L-type channel blocker, had no significant effect. Furthermore, Nif repressed JA-induced gene expression of JR1 but verapamil did not. JA-induced gene expression could be mimicked by higher concentration of extracellular Ca2+. W-7 [N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide], an antagonist of calmodulin (CaM), blocked the JA induction of JR1 expression while W-5 [N-(6-aminohexyl)-1-naphthalenesulfonamide], its inactive antagonist, had no apparent effect. These data provide the evidence that the influx of extracellular Ca2+ through Nif sensitive plasma membrane Ca2+ channel may be responsible for JA-induced elevation of [Ca2+]cyt and downstream gene expression, CaM may be also involved in JA signaling pathway.
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Affiliation(s)
- Qing-Peng Sun
- Guangdong Key Laboratory of Biotechnology for Plant Development, South China Normal University, Guangzhou, 510631, China
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91
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Affiliation(s)
- Craig W Whippo
- Department of Biology, Indiana University, Bloomington, IN 47405-7107, USA
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92
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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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93
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Abstract
In plant cells, the calcium ion is a ubiquitous intracellular second messenger involved in numerous signalling pathways. Variations in the cytosolic concentration of Ca2+ ([Ca2+]cyt) couple a large array of signals and responses. Here we concentrate on calcium signalling in plant defence responses, particularly on the generation of the calcium signal and downstream calcium-dependent events participating in the establishment of defence responses with special reference to calcium-binding proteins.
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Affiliation(s)
- David Lecourieux
- UMR CNRS 5546 Université Paul Sabatier, Signaux et Messages Cellulaires chez les Végétaux, Pôle de Biotechnologies Végétales, 24 chemin de Borde Rouge, BP 17, Auzeville, 31326 Castanet-Tolosan, France
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94
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Lecourieux D, Lamotte O, Bourque S, Wendehenne D, Mazars C, Ranjeva R, Pugin A. Proteinaceous and oligosaccharidic elicitors induce different calcium signatures in the nucleus of tobacco cells. Cell Calcium 2005; 38:527-38. [PMID: 16198416 DOI: 10.1016/j.ceca.2005.06.036] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 05/18/2005] [Accepted: 06/15/2005] [Indexed: 01/30/2023]
Abstract
We previously reported elevated cytosolic calcium levels in tobacco cells in response to elicitors [D. Lecourieux, C. Mazars, N. Pauly, R. Ranjeva, A. Pugin, Analysis and effects of cytosolic free calcium elevations in response to elicitors in Nicotiana plumbaginifolia cells, Plant Cell 14 (2002) 2627-2641]. These data suggested that in response to elicitors, Ca2+, as a second messenger, was involved in both systemic acquired resistance (RSA) and/or hypersensitive response (HR) depending on calcium signature. Here, we used transformed tobacco cells with apoaequorin expressed in the nucleus to monitor changes in free nuclear calcium concentrations ([Ca2+](nuc)) in response to elicitors. Two types of elicitors are compared: proteins leading to necrosis including four elicitins and harpin, and non-necrotic elicitors including flagellin (flg22) and two oligosaccharidic elicitors, namely the oligogalacturonides (OGs) and the beta-1,3-glucan laminarin. Our data indicate that the proteinaceous elicitors induced a pronounced and sustainable [Ca2+](nuc) elevation, relative to the small effects of oligosaccharidic elicitors. This [Ca2+](nuc) elevation, which seems insufficient to induce cell death, is unlikely to result directly from the diffusion of calcium from the cytosol. The [Ca2+](nuc) rise depends on free cytosolic calcium, IP3, and active oxygen species (AOS) but is independent of nitric oxide.
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Affiliation(s)
- David Lecourieux
- UMR INRA 1088/CNRS 5184/Université de Bourgogne, Plante-Microbe-Environnement, 17 rue de Sully, BP 86510, 21065 Dijon cedex, France
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95
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Du L, Poovaiah BW. Ca2+/calmodulin is critical for brassinosteroid biosynthesis and plant growth. Nature 2005; 437:741-5. [PMID: 16193053 DOI: 10.1038/nature03973] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 07/01/2005] [Indexed: 11/08/2022]
Abstract
Brassinosteroids are plant-specific steroid hormones that have an important role in coupling environmental factors, especially light, with plant growth and development. How the endogenous brassinosteroids change in response to environmental stimuli is largely unknown. Ca2+/calmodulin has an essential role in sensing and transducing environmental stimuli. Arabidopsis DWARF1 (DWF1) is responsible for an early step in brassinosteroid biosynthesis that converts 24-methylenecholesterol to campesterol. Here we show that DWF1 is a Ca2+/calmodulin-binding protein and this binding is critical for its function. Molecular genetic analysis using site-directed and deletion mutants revealed that loss of calmodulin binding completely abolished the function of DWF1 in planta, whereas partial loss of calmodulin binding resulted in a partial dwarf phenotype in complementation studies. These results provide direct proof that Ca2+/calmodulin-mediated signalling has a critical role in controlling the function of DWF1. Furthermore, we observed that DWF1 orthologues from other plants have a similar Ca2+/calmodulin-binding domain, implying that Ca2+/calmodulin regulation of DWF1 and its homologues is common in plants. These results raise the possibility of producing size-engineered crops by altering the Ca2+/calmodulin-binding property of their DWF1 orthologues.
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Affiliation(s)
- Liqun Du
- Center for Integrated Biotechnology and Department of Horticulture, Washington State University, Pullman, Washington 99164-6414, USA
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96
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Meyerhoff O, Müller K, Roelfsema MRG, Latz A, Lacombe B, Hedrich R, Dietrich P, Becker D. AtGLR3.4, a glutamate receptor channel-like gene is sensitive to touch and cold. PLANTA 2005; 222:418-27. [PMID: 15864638 DOI: 10.1007/s00425-005-1551-3] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Accepted: 03/16/2005] [Indexed: 05/02/2023]
Abstract
The Arabidopsis genome encodes for 20 members of putative ligand-gated channels, termed glutamate receptors (GLR). Despite the fact that initial studies suggested a role for GLRs in various aspects of photomorphogenesis, calcium homeostasis or aluminium toxicity, their functional properties and physiological role in plants remain elusive. Here, we have focussed on AtGLR3.4, which is ubiquitously expressed in Arabidopsis including roots, vascular bundles, mesophyll cells and guard cells. AtGLR3.4 encodes a glutamate-, touch-, and cold-sensitive member of this gene family. Abiotic stress stimuli such as touch, osmotic stress or cold stimulated AtGLR3.4 expression in an abscisic acid-independent, but calcium-dependent manner. In plants expressing the Ca(2+) -reporter apoaequorin, glutamate as well as cold elicited cytosolic calcium elevations. Upon glutamate treatment of mesophyll cells, the plasma membrane depolarised by about 120 mV. Both glutamate responses were transient in nature, sensitive to glutamate receptor antagonists, and were subject to desensitisation. One hour after eliciting the first calcium signal, a 50% recovery from desensitisation was observed, reflecting the stimulus-induced fast activation of AtGLR3.4 transcription. We thus conclude that AtGLR3.4 in particular and GLRs in general could play an important role in the Ca(2+) -based, fast transmission of environmental stress.
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Affiliation(s)
- Oliver Meyerhoff
- Molecular Plant Physiology and Biophysics, University of Wuerzburg, Julius-von-Sachs-Platz 2, 97082 Wuerzburg, Germany.
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97
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Suetsugu N, Kagawa T, Wada M. An auxilin-like J-domain protein, JAC1, regulates phototropin-mediated chloroplast movement in Arabidopsis. PLANT PHYSIOLOGY 2005; 139:151-62. [PMID: 16113208 PMCID: PMC1203365 DOI: 10.1104/pp.105.067371] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The ambient-light conditions mediate chloroplast relocation in plant cells. Under the low-light conditions, chloroplasts accumulate in the light (accumulation response), while under the high-light conditions, they avoid the light (avoidance response). In Arabidopsis (Arabidopsis thaliana), the accumulation response is mediated by two blue-light receptors, termed phototropins (phot1 and phot2) that act redundantly, and the avoidance response is mediated by phot2 alone. A mutant, J-domain protein required for chloroplast accumulation response 1 (jac1), lacks the accumulation response under weak blue light but shows a normal avoidance response under strong blue light. In dark-adapted wild-type cells, chloroplasts accumulate on the bottom of cells. Both the jac1 and phot2 mutants are defective in this chloroplast movement in darkness. Positional cloning of JAC1 reveals that this gene encodes a J-domain protein, resembling clathrin-uncoating factor auxilin at its C terminus. The amounts of JAC1 transcripts and JAC1 proteins are not regulated by light and by phototropins. A green fluorescent protein-JAC1 fusion protein showed a similar localization pattern to green fluorescent protein alone in a transient expression assay using Arabidopsis mesophyll cells and onion (Allium cepa) epidermal cells, suggesting that the JAC1 protein may be a soluble cytosolic protein. Together, these results suggest that JAC1 is an essential component of phototropin-mediated chloroplast movement.
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Affiliation(s)
- Noriyuki Suetsugu
- Division of Photobiology, National Institute for Basic Biology, Okazaki, Japan
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98
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Ok SH, Jeong HJ, Bae JM, Shin JS, Luan S, Kim KN. Novel CIPK1-associated proteins in Arabidopsis contain an evolutionarily conserved C-terminal region that mediates nuclear localization. PLANT PHYSIOLOGY 2005; 139:138-50. [PMID: 16113215 PMCID: PMC1203364 DOI: 10.1104/pp.105.065649] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Revised: 06/12/2005] [Accepted: 06/29/2005] [Indexed: 05/04/2023]
Abstract
Environmental stimuli, including light, pathogens, hormones, and abiotic stresses, elicit changes in the cytosolic Ca(2+) signatures of plant cells. However, little is known about the molecular mechanisms by which plants sense and transmit the specific cytoplasmic Ca(2+) signal into the nucleus, where gene regulation occurs to respond appropriately to the stress. In this study, we have identified two novel Arabidopsis (Arabidopsis thaliana) proteins specifically associated with Calcineurin B-Like-Interacting Protein Kinase1 (CIPK1), a member of Ser/Thr protein kinases that interact with the calcineurin B-like Ca(2+)-binding proteins. These two proteins contain a very similar C-terminal region (180 amino acids in length, 81% similarity), which is required and sufficient for both interaction with CIPK1 and translocation to the nucleus. Interestingly, the conserved C-terminal region was also found in many proteins from various eukaryotic organisms, including humans. However, none of them have been characterized so far. Taken together, these findings suggest that the two proteins containing the evolutionarily conserved C-terminal region (ECT1 and ECT2) may play a critical role in relaying the cytosolic Ca(2+) signals to the nucleus, thereby regulating gene expression.
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Affiliation(s)
- Sung Han Ok
- Department of Molecular Biology, Sejong University, Seoul, Korea
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99
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Roelfsema MRG, Hedrich R. In the light of stomatal opening: new insights into 'the Watergate'. THE NEW PHYTOLOGIST 2005; 167:665-91. [PMID: 16101906 DOI: 10.1111/j.1469-8137.2005.01460.x] [Citation(s) in RCA: 303] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Stomata can be regarded as hydraulically driven valves in the leaf surface, which open to allow CO2 uptake and close to prevent excessive loss of water. Movement of these 'Watergates' is regulated by environmental conditions, such as light, CO2 and humidity. Guard cells can sense environmental conditions and function as motor cells within the stomatal complex. Stomatal movement results from the transport of K+ salts across the guard cell membranes. In this review, we discuss the biophysical principles and mechanisms of stomatal movement and relate these to ion transport at the plasma membrane and vacuolar membrane. Studies with isolated guard cells, combined with recordings on single guard cells in intact plants, revealed that light stimulates stomatal opening via blue light-specific and photosynthetic-active radiation-dependent pathways. In addition, guard cells sense changes in air humidity and the water status of distant tissues via the stress hormone abscisic acid (ABA). Guard cells thus provide an excellent system to study cross-talk, as multiple signaling pathways induce both short- and long-term responses in these sensory cells.
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Affiliation(s)
- M Rob G Roelfsema
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Würzburg University, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
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100
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Tucker EB, Lee M, Alli S, Sookhdeo V, Wada M, Imaizumi T, Kasahara M, Hepler PK. UV-A induces two calcium waves in Physcomitrella patens. PLANT & CELL PHYSIOLOGY 2005; 46:1226-36. [PMID: 15919673 DOI: 10.1093/pcp/pci131] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Our understanding of the role of Ca2+ in blue/UV-A photoreceptor signaling in a single cell is limited. Insight into calcium signaling has now been attained in Physcomitrella patens and its cryptochrome and phototropin knock-outs. Physcomitrella patens caulonemal filaments grow in the dark by apical extension and their apical cells are highly polarized. Fura-2-dextran ratio images of the apical cell from wild type (WT), Ppcry1a/1b and PpphotA2/B1/B2 were obtained immediately following UV-A exposure (30 microW cm(-2) at 340 nm for 1,000 ms plus 30 microW cm(-2) at 380 nm for 1,000 ms) [abbreviated as 1,000 ms (340/380 nm)] and demonstrated two intracellular waves: a Ca2+ wave from the growing apical tip through the apical cap, and a wave from the junction of the neighboring cell through the vacuolar, nuclear and plastid regions. In WT, the UV-A-induced tip wave increase had a magnitude of 454.0 +/- 40 nM, traveled at a rate of 3.4 +/- 0.7 microm s(-1) and was complete within 26.6 +/- 2.3 s, while the basal vacuolar wave had a magnitude of 596.8 +/- 110 nM, a rate of 8.4 +/- 0.8 microm s(-1) and duration of 25.3 +/- 4.9 s. Subsequent Ca2+ spikes of similar magnitude followed these waves. The amplitude of the Ca2+ waves in the apical cap and basal vacuolar regions of Ppcry1a/1b were higher than those in the WT, while the duration of those in PpphotA2/B1/B2 was longer. Subsequent Ca2+ spikes occurred in WT and Ppcry1a/1b but not in PpphotA2/B1/B2. When Mn2+ was added to the culture medium, the [Ca2+](cyt) increase was delayed, did not move as a wave and lasted longer. The results indicate that plants respond to blue light and UV-A radiation by generating a wave of changes in the [Ca2+](cyt). The characteristics of these Ca2+ waves were dependent upon cryptochrome and phototropin. Blue/UV-A signaling in P. patens appears to differ from that in Arabidopsis.
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Affiliation(s)
- Edward B Tucker
- Natural Science Department, Baruch College, City University of New York, 17 Lexington Avenue, New York, NY 10010, USA.
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