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Xu L, Zhang L, Liu Y, Sod B, Li M, Yang T, Gao T, Yang Q, Long R. Overexpression of the elongation factor MtEF1A1 promotes salt stress tolerance in Arabidopsis thaliana and Medicago truncatula. BMC PLANT BIOLOGY 2023; 23:138. [PMID: 36907846 PMCID: PMC10009949 DOI: 10.1186/s12870-023-04139-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Elongation factor 1 A (EF1A), an essential regulator for protein synthesis, has been reported to participate in abiotic stress responses and environmental adaption in plants. However, the role of EF1A in abiotic stress response was barely studied in Medicago truncatula. Here, we identified elongation factor (EF) genes of M. truncatula and studied the salt stress response function of MtEF1A1 (MTR_6g021805). RESULTS A total of 34 EF genes were identified in the M. truncatula genome. Protein domains and motifs of EFs were highly conserved in plants. MtEF1A1 has the highest expression levels in root nodules and roots, followed by the leaves and stems. Transgenic Arabidopsis thaliana overexpressing MtEF1A1 was more resistant to salt stress treatment, with higher germination rate, longer roots, and more lateral roots than wild type plant. In addition, lower levels of H2O2 and malondialdehyde (MDA) were also detected in transgenic Arabidopsis. Similarly, MtEF1A1 overexpressing M. truncatula was more resistant to salt stress and had lower levels of reactive oxygen species (ROS) in leaves. Furthermore, the expression levels of abiotic stress-responsive genes (MtRD22A and MtCOR15A) and calcium-binding genes (MtCaM and MtCBL4) were upregulated in MtEF1A1 overexpressing lines of M. truncatula. CONCLUSION These results suggested that MtEF1A1 play a positive role in salt stress regulation. MtEF1A1 may realize its function by binding to calmodulin (CaM) or by participating in Ca2+-dependent signaling pathway. This study revealed that MtEF1A1 is an important regulator for salt stress response in M. truncatula, and provided potential strategy for salt-tolerant plant breeding.
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Affiliation(s)
- Lei Xu
- State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100000, China
| | - Lixia Zhang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100000, China
| | - Yajiao Liu
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100000, China
| | - Bilig Sod
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100000, China
| | - Mingna Li
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100000, China
| | - Tianhui Yang
- Institute of Animal Sciences, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan, 750000, China
| | - Ting Gao
- Institute of Animal Sciences, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan, 750000, China
| | - Qingchuan Yang
- State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100000, China
| | - Ruicai Long
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100000, China.
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Tomaž Š, Gruden K, Coll A. TGA transcription factors-Structural characteristics as basis for functional variability. FRONTIERS IN PLANT SCIENCE 2022; 13:935819. [PMID: 35958211 PMCID: PMC9360754 DOI: 10.3389/fpls.2022.935819] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
TGA transcription factors are essential regulators of various cellular processes, their activity connected to different hormonal pathways, interacting proteins and regulatory elements. Belonging to the basic region leucine zipper (bZIP) family, TGAs operate by binding to their target DNA sequence as dimers through a conserved bZIP domain. Despite sharing the core DNA-binding sequence, the TGA paralogues exert somewhat different DNA-binding preferences. Sequence variability of their N- and C-terminal protein parts indicates their importance in defining TGA functional specificity through interactions with diverse proteins, affecting their DNA-binding properties. In this review, we provide a short and concise summary on plant TGA transcription factors from a structural point of view, including the relation of their structural characteristics to their functional roles in transcription regulation.
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Affiliation(s)
- Špela Tomaž
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
- Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Kristina Gruden
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Anna Coll
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
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La VH, Lee BR, Islam MT, Mamun MA, Park SH, Bae DW, Kim TH. Characterization of Glutamate-Mediated Hormonal Regulatory Pathway of the Drought Responses in Relation to Proline Metabolism in Brassica napus L. PLANTS (BASEL, SWITZERLAND) 2020; 9:E512. [PMID: 32316109 PMCID: PMC7237994 DOI: 10.3390/plants9040512] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/06/2020] [Accepted: 04/14/2020] [Indexed: 11/16/2022]
Abstract
Proline metabolism influences the metabolic and/or signaling pathway in regulating plant stress responses. This study aimed to characterize the physiological significance of glutamate (Glu)-mediated proline metabolism in the drought stress responses, focusing on the hormonal regulatory pathway. The responses of cytosolic Ca2+ signaling, proline metabolism, and redox components to the exogenous application of Glu in well-watered or drought-stressed plants were interpreted in relation to endogenous hormone status and their signaling genes. Drought-enhanced level of abscisic acid (ABA) was concomitant with the accumulation of ROS and proline, as well as loss of reducing potential, which was assessed by measuring NAD(P)H/NAD(P)+ and GSH/GSSG ratios. Glu application to drought-stressed plants increased both salicylic acid (SA) and cytosolic Ca2+ levels, with the highest expression of calcium-dependent protein kinase (CPK5) and salicylic acid synthesis-related ICS1. The SA-enhanced CPK5 expression was closely associated with further enhancement of proline synthesis-related genes (P5CS1, P5CS2, and P5CR) expression and a reset of reducing potential with enhanced expression of redox regulating genes (TRXh5 and GRXC9) in a SA-mediated NPR1- and/or PR1-dependent manner. These results clearly indicate that Glu-activated interplay between SA- and CPK5-signaling as well as Glu-enhanced proline synthesis are crucial in the amelioration of drought stress in Brassica napus.
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Affiliation(s)
- Van Hien La
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.H.L.); (B.-R.L.); (M.T.I.); (M.A.M.); (S.-H.P.)
| | - Bok-Rye Lee
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.H.L.); (B.-R.L.); (M.T.I.); (M.A.M.); (S.-H.P.)
- Asian Pear Research Institute, Chonnam National University, Gwangju 61186, Korea
| | - Md. Tabibul Islam
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.H.L.); (B.-R.L.); (M.T.I.); (M.A.M.); (S.-H.P.)
- Alson H. Smith Jr. Agricultural Research and Extension Center, School of Plant and Environmental Sciences, Virginia Tech, Winchester, VA 22602, USA
| | - Md. Al Mamun
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.H.L.); (B.-R.L.); (M.T.I.); (M.A.M.); (S.-H.P.)
| | - Sang-Hyun Park
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.H.L.); (B.-R.L.); (M.T.I.); (M.A.M.); (S.-H.P.)
| | - Dong-Won Bae
- Biomaterial Analytical Laboratory, Central Instruments Facility, Gyeongsang National University, Jinju F52828, Korea;
| | - Tae-Hwan Kim
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture & Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.H.L.); (B.-R.L.); (M.T.I.); (M.A.M.); (S.-H.P.)
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Sall K, Dekkers BJW, Nonogaki M, Katsuragawa Y, Koyari R, Hendrix D, Willems LAJ, Bentsink L, Nonogaki H. DELAY OF GERMINATION 1-LIKE 4 acts as an inducer of seed reserve accumulation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:7-19. [PMID: 31359518 DOI: 10.1111/tpj.14485] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/10/2019] [Accepted: 06/17/2019] [Indexed: 05/18/2023]
Abstract
More than 70% of global food supply depends on seeds. The major seed reserves, such as proteins, lipids, and polysaccharides, are produced during seed maturation. Here, we report that DELAY OF GERMINATION 1-LIKE 4 (DOGL4) is a major inducer of reserve accumulation during seed maturation. The DOGL family proteins are plant-specific proteins of largely unknown biochemical function. DOGL4 shares only limited homology in amino acid sequence with DOG1, a major regulator of seed dormancy. DOGL4 was identified as one of the outstanding abscisic acid (ABA)-induced genes in our RNA sequencing analysis, whereas DOG1 was not induced by ABA. Induction of DOGL4 caused the expression of 70 seed maturation-specific genes, even in germinating seeds, including the major seed reserves ALBUMIN, CRUCIFERIN and OLEOSIN. Although DOG1 affects the expression of many seed maturation genes, the major seed reserve genes induced by DOGL4 are not altered by the dog1 mutation. Furthermore, the reduced dormancy and longevity phenotypes observed in the dog1 seeds were not observed in the dogl4 mutants, suggesting that these two genes have limited functional overlap. Taken together, these results suggest that DOGL4 is a central factor mediating reserve accumulation in seeds, and that the two DOG1 family proteins have diverged over the course of evolution into independent regulators of seed maturation, but retain some overlapping function.
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Affiliation(s)
- Khadidiatou Sall
- Department of Horticulture, Oregon State University, Corvallis, OR, 97331, USA
| | - Bas J W Dekkers
- Wageningen Seed Laboratory, Laboratory of Plant Physiology, Wageningen University, Wageningen, the Netherlands
| | - Mariko Nonogaki
- Department of Horticulture, Oregon State University, Corvallis, OR, 97331, USA
| | | | - Ryosuke Koyari
- Department of Horticulture, Oregon State University, Corvallis, OR, 97331, USA
| | - David Hendrix
- Department of Biochemistry and Biophysics, School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR, 97331, USA
| | - Leo A J Willems
- Wageningen Seed Laboratory, Laboratory of Plant Physiology, Wageningen University, Wageningen, the Netherlands
| | - Leónie Bentsink
- Wageningen Seed Laboratory, Laboratory of Plant Physiology, Wageningen University, Wageningen, the Netherlands
| | - Hiroyuki Nonogaki
- Department of Horticulture, Oregon State University, Corvallis, OR, 97331, USA
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Fang H, Liu Z, Long Y, Liang Y, Jin Z, Zhang L, Liu D, Li H, Zhai J, Pei Y. The Ca 2+ /calmodulin2-binding transcription factor TGA3 elevates LCD expression and H 2 S production to bolster Cr 6+ tolerance in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 91:1038-1050. [PMID: 28670772 DOI: 10.1111/tpj.13627] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 06/22/2017] [Indexed: 05/04/2023]
Abstract
Heavy metal (HM) contamination on agricultural land not only reduces crop yield but also causes human health concerns. As a plant gasotransmitter, hydrogen sulfide (H2 S) can trigger various defense responses and help reduce accumulation of HMs in plants; however, little is known about the regulatory mechanisms of H2 S signaling. Here, we provide evidence to answer the long-standing question about how H2 S production is elevated in the defense of plants against HM stress. During the response of Arabidopsis to chromium (Cr6+ ) stress, the transcription of L-cysteine desulfhydrase (LCD), the key enzyme for H2 S production, was enhanced through a calcium (Ca2+ )/calmodulin2 (CaM2)-mediated pathway. Biochemistry and molecular biology studies demonstrated that Ca2+ /CaM2 physically interacts with the bZIP transcription factor TGA3, a member of the 'TGACG'-binding factor family, to enhance binding of TGA3 to the LCD promoter and increase LCD transcription, which then promotes the generation of H2 S. Consistent with the roles of TGA3 and CaM2 in activating LCD expression, both cam2 and tga3 loss-of-function mutants have reduced LCD abundance and exhibit increased sensitivity to Cr6+ stress. Accordingly, this study proposes a regulatory pathway for endogenous H2 S generation, indicating that plants respond to Cr6+ stress by adjusting the binding affinity of TGA3 to the LCD promoter, which increases LCD expression and promotes H2 S production. This suggests that manipulation of the endogenous H2 S level through genetic engineering could improve the tolerance of grains to HM stress and increase agricultural production on soil contaminated with HMs.
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Affiliation(s)
- Huihui Fang
- College of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Zhiqiang Liu
- College of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Yanping Long
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yali Liang
- College of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Zhuping Jin
- College of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Liping Zhang
- College of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Danmei Liu
- College of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Hua Li
- College of Environmental and Resource Science, Shanxi University, Taiyuan, 030006, China
| | - Jixian Zhai
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yanxi Pei
- College of Life Science, Shanxi University, Taiyuan, 030006, China
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Tsuda K, Somssich IE. Transcriptional networks in plant immunity. THE NEW PHYTOLOGIST 2015; 206:932-947. [PMID: 25623163 DOI: 10.1111/nph.13286] [Citation(s) in RCA: 281] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/09/2014] [Indexed: 05/18/2023]
Abstract
Next to numerous abiotic stresses, plants are constantly exposed to a variety of pathogens within their environment. Thus, their ability to survive and prosper during the course of evolution was strongly dependent on adapting efficient strategies to perceive and to respond to such potential threats. It is therefore not surprising that modern plants have a highly sophisticated immune repertoire consisting of diverse signal perception and intracellular signaling pathways. This signaling network is intricate and deeply interconnected, probably reflecting the diverse lifestyles and infection strategies used by the multitude of invading phytopathogens. Moreover it allows signal communication between developmental and defense programs thereby ensuring that plant growth and fitness are not significantly retarded. How plants integrate and prioritize the incoming signals and how this information is transduced to enable appropriate immune responses is currently a major research area. An important finding has been that pathogen-triggered cellular responses involve massive transcriptional reprogramming within the host. Additional key observations emerging from such studies are that transcription factors (TFs) are often sites of signal convergence and that signal-regulated TFs act in concert with other context-specific TFs and transcriptional co-regulators to establish sensory transcription regulatory networks required for plant immunity.
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Affiliation(s)
- Kenichi Tsuda
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, Cologne, 50829, Germany
| | - Imre E Somssich
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, Cologne, 50829, Germany
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7
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Poovaiah B, Du L, Wang H, Yang T. Recent advances in calcium/calmodulin-mediated signaling with an emphasis on plant-microbe interactions. PLANT PHYSIOLOGY 2013; 163:531-42. [PMID: 24014576 PMCID: PMC3793035 DOI: 10.1104/pp.113.220780] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 08/28/2013] [Indexed: 05/18/2023]
Abstract
Calcium/calmodulin-mediated signaling contributes in diverse roles in plant growth, development, and response to environmental stimuli .
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Affiliation(s)
| | | | - Huizhong Wang
- Department of Horticulture, Washington State University, Pullman, Washington 99164–6414 (B.W.P., L.D.)
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036, People’s Republic of China (L.D., H.W.); and
- Food Quality Laboratory, Beltsville Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Beltsville, Maryland 20705 (T.Y.)
| | - Tianbao Yang
- Department of Horticulture, Washington State University, Pullman, Washington 99164–6414 (B.W.P., L.D.)
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036, People’s Republic of China (L.D., H.W.); and
- Food Quality Laboratory, Beltsville Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Beltsville, Maryland 20705 (T.Y.)
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8
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Yang S, Wang F, Guo F, Meng JJ, Li XG, Dong ST, Wan SB. Exogenous calcium alleviates photoinhibition of PSII by improving the xanthophyll cycle in peanut (Arachis hypogaea) leaves during heat stress under high irradiance. PLoS One 2013; 8:e71214. [PMID: 23940721 PMCID: PMC3737129 DOI: 10.1371/journal.pone.0071214] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 06/27/2013] [Indexed: 11/24/2022] Open
Abstract
Peanut is one of the calciphilous plants. Calcium (Ca) serves as a ubiquitous central hub in a large number of signaling pathways. The effect of exogenous calcium nitrate [Ca(NO3)2] (6 mM) on the dissipation of excess excitation energy in the photosystem II (PSII) antenna, especially on the level of D1 protein and the xanthophyll cycle in peanut plants under heat (40°C) and high irradiance (HI) (1 200 µmol m(-2) s(-1)) stress were investigated. Compared with the control plants [cultivated in 0 mM Ca(NO3)2 medium], the maximal photochemical efficiency of PSII (Fv/Fm) in Ca(2+)-treated plants showed a slighter decrease after 5 h of stress, accompanied by higher non-photochemical quenching (NPQ), higher expression of antioxidative genes and less reactive oxygen species (ROS) accumulation. Meanwhile, higher content of D1 protein and higher ratio of (A+Z)/(V+A+Z) were also detected in Ca(2+)-treated plants under such stress. These results showed that Ca(2+) could help protect the peanut photosynthetic system from severe photoinhibition under heat and HI stress by accelerating the repair of D1 protein and improving the de-epoxidation ratio of the xanthophyll cycle. Furthermore, EGTA (a chelant of Ca ion), LaCl3 (a blocker of Ca(2+) channel in cytoplasmic membrane), and CPZ [a calmodulin (CaM) antagonist] were used to analyze the effects of Ca(2+)/CaM on the variation of (A+Z)/(V+A+Z) (%) and the expression of violaxanthin de-epoxidase (VDE). The results indicated that CaM, an important component of the Ca(2+) signal transduction pathway, mediated the expression of the VDE gene in the presence of Ca to improve the xanthophyll cycle.
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Affiliation(s)
- Sha Yang
- High-Tech Research Center of Shandong Academy of Agricultural Sciences, Ji’nan, China
- Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Ji’nan, China
| | - Fang Wang
- High-Tech Research Center of Shandong Academy of Agricultural Sciences, Ji’nan, China
- College of Life Sciences, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an, China
| | - Feng Guo
- High-Tech Research Center of Shandong Academy of Agricultural Sciences, Ji’nan, China
- Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Ji’nan, China
| | - Jing-Jing Meng
- High-Tech Research Center of Shandong Academy of Agricultural Sciences, Ji’nan, China
- Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Ji’nan, China
| | - Xin-Guo Li
- High-Tech Research Center of Shandong Academy of Agricultural Sciences, Ji’nan, China
- Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Ji’nan, China
| | - Shu-Ting Dong
- College of Life Sciences, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an, China
| | - Shu-Bo Wan
- Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Ji’nan, China
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Han HJ, Park HC, Byun HJ, Lee SM, Kim HS, Yun DJ, Cho MJ, Chung WS. The transcriptional repressor activity of ASYMMETRIC LEAVES1 is inhibited by direct interaction with calmodulin in Arabidopsis. PLANT, CELL & ENVIRONMENT 2012; 35:1969-82. [PMID: 22554014 DOI: 10.1111/j.1365-3040.2012.02530.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Calmodulin (CaM), a key Ca2+ sensor, regulates diverse cellular processes by modulating the activity of a variety of enzymes and proteins. However, little is known about the biological function of CaM in plant development. In this study, an ASYMMETRIC LEAVES1 (AS1) transcription factor was isolated as a CaM-binding protein. AS1 contains two putative CaM-binding domains (CaMBDs) at the N-terminus. Using domain mapping analysis, both predicted domains were identified as authentic Ca2+ -dependent CaMBDs. We identified three hydrophobic amino acid residues for CaM binding, Trp49 in CaMBDI, and Trp81 and Phe103 in CaMBDII. The interactions of AS1 with CaM were verified in yeast and plant cells. Based on electrophoretic mobility shift assays, CaM inhibited the DNA-binding activity of the AS1/AS2 complex to two cis-regulatory motifs in the KNAT1 promoter. Furthermore, CaM relieved the suppression of KNAT1 transcription by AS1 not only in transient expression assays of protoplasts but also by the overexpression of a CaM-binding negative form of AS1 in as1 mutant plant. Our study suggests that CaM, a calcium sensor, can be involved in the transcriptional control of meristem cell-specific genes by the inhibition of AS1 under the condition of higher levels of Ca2+ in plants.
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Affiliation(s)
- Hay Ju Han
- Division of Applied Life Science (BK21 program) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, Korea
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Di Sole F, Vadnagara K, Moe OW, Babich V. Calcineurin homologous protein: a multifunctional Ca2+-binding protein family. Am J Physiol Renal Physiol 2012; 303:F165-79. [PMID: 22189947 PMCID: PMC3404583 DOI: 10.1152/ajprenal.00628.2011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 05/17/2012] [Indexed: 12/13/2022] Open
Abstract
The calcineurin homologous protein (CHP) belongs to an evolutionarily conserved Ca(2+)-binding protein subfamily. The CHP subfamily is composed of CHP1, CHP2, and CHP3, which in vertebrates share significant homology at the protein level with each other and between other Ca(2+)-binding proteins. The CHP structure consists of two globular domains containing from one to four EF-hand structural motifs (calcium-binding regions composed of two helixes, E and F, joined by a loop), the myristoylation, and nuclear export signals. These structural features are essential for the function of the three members of the CHP subfamily. Indeed, CHP1-CHP3 have multiple and diverse essential functions, ranging from the regulation of the plasma membrane Na(+)/H(+) exchanger protein function, to carrier vesicle trafficking and gene transcription. The diverse functions attributed to the CHP subfamily rendered an understanding of its action highly complex and often controversial. This review provides a comprehensive and organized examination of the properties and physiological roles of the CHP subfamily with a view to revealing a link between CHP diverse functions.
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Affiliation(s)
- Francesca Di Sole
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75390-8885, USA.
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Mazars C, Brière C, Bourque S, Thuleau P. Nuclear calcium signaling: an emerging topic in plants. Biochimie 2011; 93:2068-74. [PMID: 21683118 DOI: 10.1016/j.biochi.2011.05.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 05/31/2011] [Indexed: 01/02/2023]
Abstract
The calcium ion is probably one of the most studied second messenger both in plant and animal fields. A large number of reviews have browsed the diversity of cytosolic calcium signatures and evaluated their pleiotropic roles in plant and animal cells. In the recent years, an increasing number of reviews has focused on nuclear calcium, especially on the possible roles of nuclear calcium concentration variations on nuclear activities. Experiments initially performed on animal cells gave conflicting results that brought about a controversy about the ability of the nucleus to generate its own calcium signals and to regulate its calcium level. But in plant cells, several converging scientific pieces of evidence support the hypothesis of nucleus autonomy. The present review briefly summarizes data supporting this hypothesis and tries to put forward some possible roles for these nucleus-generated calcium signals in controlling nuclear activity.
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Affiliation(s)
- Christian Mazars
- Université de Toulouse, Université Paul Sabatier, Laboratoire de Recherche en Sciences végétales, Castanet-Tolosan, France.
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Reddy ASN, Ali GS, Celesnik H, Day IS. Coping with stresses: roles of calcium- and calcium/calmodulin-regulated gene expression. THE PLANT CELL 2011; 23:2010-32. [PMID: 21642548 PMCID: PMC3159525 DOI: 10.1105/tpc.111.084988] [Citation(s) in RCA: 408] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/02/2011] [Accepted: 05/16/2011] [Indexed: 05/18/2023]
Abstract
Abiotic and biotic stresses are major limiting factors of crop yields and cause billions of dollars of losses annually around the world. It is hoped that understanding at the molecular level how plants respond to adverse conditions and adapt to a changing environment will help in developing plants that can better cope with stresses. Acquisition of stress tolerance requires orchestration of a multitude of biochemical and physiological changes, and most of these depend on changes in gene expression. Research during the last two decades has established that different stresses cause signal-specific changes in cellular Ca(2+) level, which functions as a messenger in modulating diverse physiological processes that are important for stress adaptation. In recent years, many Ca(2+) and Ca(2+)/calmodulin (CaM) binding transcription factors (TFs) have been identified in plants. Functional analyses of some of these TFs indicate that they play key roles in stress signaling pathways. Here, we review recent progress in this area with emphasis on the roles of Ca(2+)- and Ca(2+)/CaM-regulated transcription in stress responses. We will discuss emerging paradigms in the field, highlight the areas that need further investigation, and present some promising novel high-throughput tools to address Ca(2+)-regulated transcriptional networks.
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Affiliation(s)
- Anireddy S N Reddy
- Department of Biology, Program in Molecular Plant Biology, Program in Cell and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA.
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13
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Lachaud C, Da Silva D, Cotelle V, Thuleau P, Xiong TC, Jauneau A, Brière C, Graziana A, Bellec Y, Faure JD, Ranjeva R, Mazars C. Nuclear calcium controls the apoptotic-like cell death induced by d-erythro-sphinganine in tobacco cells. Cell Calcium 2010; 47:92-100. [PMID: 20022633 DOI: 10.1016/j.ceca.2009.11.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 11/24/2009] [Accepted: 11/26/2009] [Indexed: 01/02/2023]
Abstract
Studies performed in animals have highlighted the major role of sphingolipids in regulating the balance between cell proliferation and cell death. Sphingolipids have also been shown to induce cell death in plants via calcium-based signalling pathways but the contribution of free cytosolic and/or nuclear calcium in the overall process has never been evaluated. Here, we show that increase in tobacco BY-2 cells of the endogenous content of Long Chain Bases (LCBs) caused by external application of d-erythro-sphinganine (DHS) is followed by immediate dose-dependent elevations of cellular free calcium concentration within the first minute in the cytosol and 10min later in the nucleus. Cells challenged with DHS enter a death process through apoptotic-like mechanisms. Lanthanum chloride, a general blocker of calcium entry, suppresses the cellular calcium variations and the PCD induced by DHS. Interestingly, dl-2-amino-5-phosphopentanoic acid (AP5) and [(+)-dizocilpine] (MK801), two inhibitors of animal and plant ionotropic glutamate receptors, suppress DHS-induced cell death symptoms by selectively inhibiting the variations of nuclear calcium concentration. The selective action of these compounds demonstrates the crucial role of nuclear calcium signature in controlling DHS-induced cell death in tobacco cells.
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Affiliation(s)
- Christophe Lachaud
- Université de Toulouse, UPS, UMR CNRS-UPS, Surfaces Cellulaires et Signalisation chez les Végétaux, Auzeville, Castanet-Tolosan, France
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14
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Koo SC, Choi MS, Chun HJ, Shin DB, Park BS, Kim YH, Park HM, Seo HS, Song JT, Kang KY, Yun DJ, Chung WS, Cho MJ, Kim MC. The calmodulin-binding transcription factor OsCBT suppresses defense responses to pathogens in rice. Mol Cells 2009; 27:563-70. [PMID: 19466605 DOI: 10.1007/s10059-009-0081-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 03/30/2009] [Accepted: 04/07/2009] [Indexed: 12/30/2022] Open
Abstract
We previously isolated the OsCBT gene, which encodes a calmodulin (CaM)-binding protein, from a rice expression library constructed from fungal elicitor-treated rice suspension cells. In order to understand the function of OsCBT in rice, we isolated and characterized a T-DNA insertion mutant allele named oscbt-1. The oscbt-1 mutant exhibits reduced levels of OsCBT transcripts and no significant morphological changes compared to wild-type plant although the growth of the mutant is stunted. However, oscbt-1 mutants showed significant resistance to two major rice pathogens. The growth of the rice blast fungus Magnaporthe grisea, as well as the bacterial pathogen Xanthomonas oryzae pv. oryzae was significantly suppressed in oscbt-1 plants. Histochemical analysis indicated that the hypersensitive-response was induced in the oscbt-1 mutant in response to compatible strains of fungal pathogens. OsCBT expression was induced upon challenge with fungal elicitor. We also observed significant increase in the level of pathogenesis-related genes in the oscbt-1 mutant even under pathogen-free condition. Taken together, the results support an idea that OsCBT might act as a negative regulator on plant defense.
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Affiliation(s)
- Sung Cheol Koo
- Division of Applied Life Science (Brain Korea 21 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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15
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Park HC, Kim ML, Kang YH, Jeong JC, Cheong MS, Choi W, Lee SY, Cho MJ, Kim MC, Chung WS, Yun DJ. Functional analysis of the stress-inducible soybean calmodulin isoform-4 (GmCaM-4) promoter in transgenic tobacco plants. Mol Cells 2009; 27:475-80. [PMID: 19390829 DOI: 10.1007/s10059-009-0063-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 02/24/2009] [Accepted: 02/26/2009] [Indexed: 10/20/2022] Open
Abstract
The transcription of soybean (Glycine max) calmodulin isoform-4 (GmCaM-4) is dramatically induced within 0.5 h of exposure to pathogen or NaCl. Core cis-acting elements that regulate the expression of the GmCaM-4 gene in response to pathogen and salt stress were previously identified, between -1,207 and -1,128 bp, and between -858 and -728 bp, in the GmCaM-4 promoter. Here, we characterized the properties of the DNA-binding complexes that form at the two core cis-acting elements of the GmCaM-4 promoter in pathogen-treated nuclear extracts. We generated GUS reporter constructs harboring various deletions of approximately 1.3-kb GmCaM-4 promoter, and analyzed GUS expression in tobacco plants transformed with these constructs. The GUS expression analysis suggested that the two previously identified core regions are involved in inducing GmCaM-4 expression in the heterologous system. Finally, a transient expression assay of Arabidopsis protoplasts showed that the GmCaM-4 promoter produced greater levels of GUS activity than did the CaMV35S promoter after pathogen or NaCl treatments, suggesting that the GmCaM-4 promoter may be useful in the production of conditional gene expression systems.
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Affiliation(s)
- Hyeong Cheol Park
- Division of Applied Life Science, Plant Molecular Biology and Biotechnology Research Center and Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju, Korea.
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16
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Induction of TLR4-target genes entails calcium/calmodulin-dependent regulation of chromatin remodeling. Proc Natl Acad Sci U S A 2009; 106:1169-74. [PMID: 19164553 DOI: 10.1073/pnas.0811274106] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Upon toll-like receptor 4 (TLR4) signaling in macrophages, the mammalian Swi/Snf-like BAF chromatin remodeling complex is recruited to many TLR4 target genes where it remodels their chromatin to promote transcription. Here, we show that, surprisingly, recruitment is not sufficient for chromatin remodeling; a second event, dependent on calcium/calmodulin (CaM), is additionally required. Calcium/CaM directly binds the HMG domain of the BAF57 subunit within the BAF complex. Calcium/CaM antagonists, including a CaM-binding peptide derived from BAF57, abolish BAF-dependent remodeling and gene expression without compromising BAF recruitment. BAF57 RNAi and BAF57 dominant negative mutants defective in CaM binding similarly impair the induction of BAF target genes. Our data implicate calcium/CaM in TLR4 signaling, and reveal a previously undescribed, recruitment-independent mode of regulation of the BAF complex that is probably achieved through a direct CaM-BAF interaction.
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17
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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: 85] [Impact Index Per Article: 5.7] [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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18
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Kushwaha R, Singh A, Chattopadhyay S. Calmodulin7 plays an important role as transcriptional regulator in Arabidopsis seedling development. THE PLANT CELL 2008; 20:1747-59. [PMID: 18621945 PMCID: PMC2518239 DOI: 10.1105/tpc.107.057612] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2007] [Revised: 06/15/2008] [Accepted: 06/27/2008] [Indexed: 05/21/2023]
Abstract
Although calmodulin (CaM) is known to play multiple regulatory roles in eukaryotes, its direct function as transcriptional regulator is unknown. Furthermore, the physiological functions of CaM are largely unknown in plants. Here, we show that one of the four Arabidopsis thaliana CaM isoforms, CAM7, is a transcriptional regulator that directly interacts with the promoters of light-inducible genes and promotes photomorphogenesis. CAM7 overexpression causes hyperphotomorphogenic growth and an increase in the expression of light-inducible genes. Mutations in CAM7 produce no visible effects on photomorphogenic growth, indicating likely redundant gene functions. However, cam7 mutants display reduced expression of light-inducible genes, and cam7 hy5 double mutants show an enhancement of the hy5 phenotype. Moreover, overexpression of CAM7 can partly suppress the hy5 phenotype, indicating that the two factors work together to control light-induced seedling development. The mutational and transgenic studies, together with physiological analyses, illustrate the concerted function of CAM7 and HY5 basic leucine zipper transcription factor in Arabidopsis seedling development.
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Affiliation(s)
- Ritu Kushwaha
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
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19
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Popescu SC, Snyder M, Dinesh-Kumar S. Arabidopsis protein microarrays for the high-throughput identification of protein-protein interactions. PLANT SIGNALING & BEHAVIOR 2007; 2:416-20. [PMID: 19704619 PMCID: PMC2634232 DOI: 10.4161/psb.2.5.4416] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 05/10/2007] [Indexed: 05/20/2023]
Abstract
Protein microarray technology has emerged as a powerful new approach for the study of thousands of proteins simultaneously. Protein microarrays have been used for a wide variety of applications for the human and yeast systems. In a recent study, we demonstrated that Arabidopsis functional protein microarrays can be generated and employed to characterize the function of plant proteins. The arrayed proteins were produced using an optimized large-scale plant-based expression system. In a proof-of concept study, 173 known and novel potential substrates of calmodulin (CaM) and calmodulin-like proteins (CML) were identified in an unbiased and high-throughput manner. The information documented here on novel potential CaM targets provides new testable hypotheses in the area of CaM/Ca(2+)-regulated processes and represents a resource of functional information for the scientific community.
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Affiliation(s)
- Sorina C Popescu
- Department of Molecular, Cellular and Developmental Biology; Yale University; New Haven, Connecticut USA
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20
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Radivojac P, Vucetic S, O'Connor TR, Uversky VN, Obradovic Z, Dunker AK. Calmodulin signaling: analysis and prediction of a disorder-dependent molecular recognition. Proteins 2007; 63:398-410. [PMID: 16493654 DOI: 10.1002/prot.20873] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Calmodulin (CaM) signaling involves important, wide spread eukaryotic protein-protein interactions. The solved structures of CaM associated with several of its binding targets, the distinctive binding mechanism of CaM, and the significant trypsin sensitivity of the binding targets combine to indicate that the process of association likely involves coupled binding and folding for both CaM and its binding targets. Here, we use bioinformatics approaches to test the hypothesis that CaM-binding targets are intrinsically disordered. We developed a predictor of CaM-binding regions and estimated its performance. Per residue accuracy of this predictor reached 81%, which, in combination with a high recall/precision balance at the binding region level, suggests high predictability of CaM-binding partners. An analysis of putative CaM-binding proteins in yeast and human strongly indicates that their molecular functions are related to those of intrinsically disordered proteins. These findings add to the growing list of examples in which intrinsically disordered protein regions are indicated to provide the basis for cell signaling and regulation.
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Affiliation(s)
- Predrag Radivojac
- School of Informatics, Indiana University, Bloomington, Indiana, USA
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21
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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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22
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Levy M, Wang Q, Kaspi R, Parrella MP, Abel S. Arabidopsis IQD1, a novel calmodulin-binding nuclear protein, stimulates glucosinolate accumulation and plant defense. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 43:79-96. [PMID: 15960618 DOI: 10.1111/j.1365-313x.2005.02435.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Glucosinolates are a class of secondary metabolites with important roles in plant defense and human nutrition. To uncover regulatory mechanisms of glucosinolate production, we screened Arabidopsis thaliana T-DNA activation-tagged lines and identified a high-glucosinolate mutant caused by overexpression of IQD1 (At3g09710). A series of gain- and loss-of-function IQD1 alleles in different accessions correlates with increased and decreased glucosinolate levels, respectively. IQD1 encodes a novel protein that contains putative nuclear localization signals and several motifs known to mediate calmodulin binding, which are arranged in a plant-specific segment of 67 amino acids, called the IQ67 domain. We demonstrate that an IQD1-GFP fusion protein is targeted to the cell nucleus and that recombinant IQD1 binds to calmodulin in a Ca(2+)-dependent fashion. Analysis of steady-state messenger RNA levels of glucosinolate pathway genes indicates that IQD1 affects expression of multiple genes with roles in glucosinolate metabolism. Histochemical analysis of tissue-specific IQD1::GUS expression reveals IQD1 promoter activity mainly in vascular tissues of all organs, consistent with the expression patterns of several glucosinolate-related genes. Interestingly, overexpression of IQD1 reduces insect herbivory, which we demonstrated in dual-choice assays with the generalist phloem-feeding green peach aphid (Myzus persicae), and in weight-gain assays with the cabbage looper (Trichoplusia ni), a generalist-chewing lepidopteran. As IQD1 is induced by mechanical stimuli, we propose IQD1 to be novel nuclear factor that integrates intracellular Ca(2+) signals to fine-tune glucosinolate accumulation in response to biotic challenge.
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Affiliation(s)
- Maggie Levy
- Department of Plant Sciences, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
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23
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Reddy VS, Reddy ASN. Proteomics of calcium-signaling components in plants. PHYTOCHEMISTRY 2004; 65:1745-76. [PMID: 15276435 DOI: 10.1016/j.phytochem.2004.04.033] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Revised: 03/30/2004] [Indexed: 05/21/2023]
Abstract
Calcium functions as a versatile messenger in mediating responses to hormones, biotic/abiotic stress signals and a variety of developmental cues in plants. The Ca(2+)-signaling circuit consists of three major "nodes"--generation of a Ca(2+)-signature in response to a signal, recognition of the signature by Ca2+ sensors and transduction of the signature message to targets that participate in producing signal-specific responses. Molecular genetic and protein-protein interaction approaches together with bioinformatic analysis of the Arabidopsis genome have resulted in identification of a large number of proteins at each "node"--approximately 80 at Ca2+ signature, approximately 400 sensors and approximately 200 targets--that form a myriad of Ca2+ signaling networks in a "mix and match" fashion. In parallel, biochemical, cell biological, genetic and transgenic approaches have unraveled functions and regulatory mechanisms of a few of these components. The emerging paradigm from these studies is that plants have many unique Ca2+ signaling proteins. The presence of a large number of proteins, including several families, at each "node" and potential interaction of several targets by a sensor or vice versa are likely to generate highly complex networks that regulate Ca(2+)-mediated processes. Therefore, there is a great demand for high-throughput technologies for identification of signaling networks in the "Ca(2+)-signaling-grid" and their roles in cellular processes. Here we discuss the current status of Ca2+ signaling components, their known functions and potential of emerging high-throughput genomic and proteomic technologies in unraveling complex Ca2+ circuitry.
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Affiliation(s)
- Vaka S Reddy
- Department of Biology and Program in Cell and Molecular Biology, Colorado State University, 200 West Lake Street, Fort Collins, CO 80523, USA
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24
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Abstract
Calcium is an essential plant nutrient. It is required for various structural roles in the cell wall and membranes, it is a counter-cation for inorganic and organic anions in the vacuole, and the cytosolic Ca2+ concentration ([Ca2+]cyt) is an obligate intracellular messenger coordinating responses to numerous developmental cues and environmental challenges. This article provides an overview of the nutritional requirements of different plants for Ca, and how this impacts on natural flora and the Ca content of crops. It also reviews recent work on (a) the mechanisms of Ca2+ transport across cellular membranes, (b) understanding the origins and specificity of [Ca2+]cyt signals and (c) characterizing the cellular [Ca2+]cyt-sensors (such as calmodulin, calcineurin B-like proteins and calcium-dependent protein kinases) that allow plant cells to respond appropriately to [Ca2+]cyt signals.
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Affiliation(s)
- Philip J White
- Horticulture Research International, Wellesbourne, Warwick CV35 9EF, UK.
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25
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Antonsson A, Hughes K, Edin S, Grundström T. Regulation of c-Rel nuclear localization by binding of Ca2+/calmodulin. Mol Cell Biol 2003; 23:1418-27. [PMID: 12556500 PMCID: PMC141150 DOI: 10.1128/mcb.23.4.1418-1427.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The NF-kappa B/Rel family of transcription factors participates in the control of a wide array of genes, including genes involved in embryonic development and regulation of immune, inflammation, and stress responses. In most cells, inhibitory I kappa B proteins sequester NF-kappa B/Rel in the cytoplasm. Cellular stimulation results in the degradation of I kappa B and modification of NF-kappa B/Rel proteins, allowing NF-kappa B/Rel to translocate to the nucleus and act on its target genes. Calmodulin (CaM) is a highly conserved, ubiquitously expressed Ca(2+) binding protein that serves as a key mediator of intracellular Ca(2+) signals. Here we report that two members of the NF-kappa B/Rel family, c-Rel and RelA, interact directly with Ca(2+)-loaded CaM. The interaction with CaM is greatly enhanced by cell stimulation, and this enhancement is blocked by addition of I kappa B. c-Rel and RelA interact with CaM through a similar sequence near the nuclear localization signal. Compared to the wild-type protein, CaM binding-deficient mutants of c-Rel exhibit increases in both nuclear accumulation and transcriptional activity on the interleukin 2 and granulocyte macrophage colony-stimulating factor promoters in the presence of a Ca(2+) signal. Conversely, for RelA neither nuclear accumulation nor transcriptional activity on these promoters is increased by mutation of the sequence interacting with CaM. Our results suggest that CaM binds c-Rel and RelA after their release from I kappa B and can inhibit nuclear import of c-Rel while letting RelA translocate to the nucleus and act on its target genes. CaM can therefore differentially regulate the activation of NF-kappa B/Rel proteins following stimulation.
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Affiliation(s)
- Asa Antonsson
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
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26
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Camas A, Cárdenas L, Quinto C, Lara M. Expression of different calmodulin genes in bean (Phaseolus vulgaris L.): role of nod factor on calmodulin gene regulation. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2002; 15:428-436. [PMID: 12036273 DOI: 10.1094/mpmi.2002.15.5.428] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three calmodulin (PvCaM-1, PvCaM-2, and PvCaM-3) clones were isolated from a Phaseolus vulgaris nodule cDNA library. All clones contain the complete coding region and are 62 to 74% homologous within this region. Compared to plant CaM consensus sequences, PvCaM-2 has a novel tyrosine118 residue, representing a putative phosphorylation site. Southern analysis suggested that calmodulin is encoded by a gene family. These three CaM clones are expressed mainly in young tissues and meristems. The expression pattern of PvCaM-2 and PvCaM-3 is almost identical but different from that of PvCaM-1, suggesting that PvCaM-1 is a well-defined CaM gene, whereas PvCaM-2 and PvCaM-3 could be alleles. PvCaM clones are expressed early in nodules, and transcript levels increase from nodule primordia to nodule-like structures induced by the Nod factor. Conversely, in roots, Nod factor lowers mRNA levels of all three PvCaM clones, but especially of PvCaM-1. Inhibition of PvCaM-1 expression also is observed when 2,3,5-triiodobenzoic acid is added and is prevented when roots are treated with indole-3-acetic acid, suggesting that PvCaM-1 regulation is related to the Nod factor inhibition of polar auxin transport. These results could suggest that CaM clones do not participate in the early signaling generated by the Nod factor but do participate in early events of nodule formation.
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Affiliation(s)
- Alberto Camas
- Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Cuernavaca, Morelos
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27
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Yang T, Poovaiah BW. Hydrogen peroxide homeostasis: activation of plant catalase by calcium/calmodulin. Proc Natl Acad Sci U S A 2002; 99:4097-102. [PMID: 11891305 PMCID: PMC122654 DOI: 10.1073/pnas.052564899] [Citation(s) in RCA: 237] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2001] [Indexed: 11/18/2022] Open
Abstract
Environmental stimuli such as UV, pathogen attack, and gravity can induce rapid changes in hydrogen peroxide (H(2)O(2)) levels, leading to a variety of physiological responses in plants. Catalase, which is involved in the degradation of H(2)O(2) into water and oxygen, is the major H(2)O(2)-scavenging enzyme in all aerobic organisms. A close interaction exists between intracellular H(2)O(2) and cytosolic calcium in response to biotic and abiotic stresses. Studies indicate that an increase in cytosolic calcium boosts the generation of H(2)O(2). Here we report that calmodulin (CaM), a ubiquitous calcium-binding protein, binds to and activates some plant catalases in the presence of calcium, but calcium/CaM does not have any effect on bacterial, fungal, bovine, or human catalase. These results document that calcium/CaM can down-regulate H(2)O(2) levels in plants by stimulating the catalytic activity of plant catalase. Furthermore, these results provide evidence indicating that calcium has dual functions in regulating H(2)O(2) homeostasis, which in turn influences redox signaling in response to environmental signals in plants.
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Affiliation(s)
- T Yang
- Laboratory of Plant Molecular Biology and Physiology, Department of Horticulture, Washington State University, Pullman, WA 99164-6414, USA
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28
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Luan S, Kudla J, Rodriguez-Concepcion M, Yalovsky S, Gruissem W. Calmodulins and calcineurin B-like proteins: calcium sensors for specific signal response coupling in plants. THE PLANT CELL 2002; 14 Suppl:S389-400. [PMID: 12045290 PMCID: PMC151268 DOI: 10.1105/tpc.001115] [Citation(s) in RCA: 411] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2001] [Accepted: 03/24/2002] [Indexed: 05/17/2023]
Affiliation(s)
- Sheng Luan
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720
| | - Jörg Kudla
- Molekulare Botanik, Universität Ulm, Albert-Einstein-Allee 11, 89069 Ulm, Germany
| | - Manuel Rodriguez-Concepcion
- Departament de Bioquímica i Biologia Molecular, Universitat de Barcelona, Martí i Franquès 1-7, 08028 Barcelona, Spain
| | - Shaul Yalovsky
- Department of Plant Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Wilhelm Gruissem
- Institute of Plant Sciences, Swiss Federal Institute of Technology, ETH Zentrum, CH-8092 Zurich, Switzerland
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29
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Pauly N, Knight MR, Thuleau P, Graziana A, Muto S, Ranjeva R, Mazars C. The nucleus together with the cytosol generates patterns of specific cellular calcium signatures in tobacco suspension culture cells. Cell Calcium 2001; 30:413-21. [PMID: 11728136 DOI: 10.1054/ceca.2001.0250] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Plant cell suspension cultures respond to osmotic changes by alterations in levels of free cellular calcium. Using the aequorin recombinant method, we have measured the spatial and temporal characteristics of calcium signatures in the nucleus and the cytosol of BY-2 tobacco suspension cells challenged with hypo- or hyper-osmotic shock. We show here that the nuclear compartment contributes together with the cytosol to produce calcium signal patterns that discriminate hypo- from hyper-osmotic treatments, i.e. turgor from tension. We also demonstrate that calcium responses in the nucleus and the cytosol are differentially modulated by the strength and the nature of hyper-osmotic treatments. We conclude that qualitative and quantitative changes in the parameters of an external stimulus such as osmotic changes are converted into calcium signatures, distinctive in their temporal and subcellular characteristics, involving both the nucleus and the cytosol. Our results illustrate the versatility of calcium signaling in plant cells. In addition to the physiological 'address' of the cell, the compartmentation of the calcium signal is probably an important parameter in encoding response specificity.
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Affiliation(s)
- N Pauly
- Signaux et Messages Cellulaires chez les Végétaux, Centre National de la Recherche Scientifique, Université Paul Sabatier, Castanet-Tolosan, France
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30
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Snedden WA, Fromm H. Calmodulin as a versatile calcium signal transducer in plants. THE NEW PHYTOLOGIST 2001; 151:35-66. [PMID: 33873389 DOI: 10.1046/j.1469-8137.2001.00154.x] [Citation(s) in RCA: 260] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The complexity of Ca2+ patterns observed in eukaryotic cells, including plants, has led to the hypothesis that specific patterns of Ca2+ propagation, termed Ca2+ signatures, encode information and relay it to downstream elements (effectors) for translation into appropriate cellular responses. Ca2+ -binding proteins (sensors) play a key role in decoding Ca2+ signatures and transducing signals by activating specific targets and pathways. Calmodulin is a Ca2+ sensor known to modulate the activity of many mammalian proteins, whose targets in plants are now being actively characterized. Plants possess an interesting and rapidly growing list of calmodulin targets with a variety of cellular roles. Nevertheless, many targets appear to be unique to plants and remain uncharacterized, calling for a concerted effort to elucidate their functions. Moreover, the extended family of calmodulin-related proteins in plants consists of evolutionarily divergent members, mostly of unknown function, although some have recently been implicated in stress responses. It is hoped that advances in functional genomics, and the research tools it generates, will help to explain themultiplicity of calmodulin genes in plants, and to identify their downstream effectors. This review summarizes current knowledge of the Ca2+ -calmodulin messenger system in plants and presents suggestions for future areas of research. Contents I. Introduction 36 II. CaM isoforms and CaM-like proteins 37 III. CaM-target proteins 42 IV. CaM and nuclear functions 46 V. Regulation of ion transport 49 VI. CaM and plant responses to environmental stimuli 52 VII. Conclusions and future studies 58 Acknowledgements 59 References 59.
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Affiliation(s)
- Wayne A Snedden
- Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Hillel Fromm
- Centre for Plant Sciences, Leeds Institute for Biotechnology and Agriculture (LIBA), School of Biology, University of Leeds, Leeds LS2 9JT, UK
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31
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Reddy AS. Calcium: silver bullet in signaling. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2001; 160:381-404. [PMID: 11166425 DOI: 10.1016/s0168-9452(00)00386-1] [Citation(s) in RCA: 199] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Accumulating evidence suggests that Ca(2+) serves as a messenger in many normal growth and developmental process and in plant responses to biotic and abiotic stresses. Numerous signals have been shown to induce transient elevation of [Ca(2+)](cyt) in plants. Genetic, biochemical, molecular and cell biological approaches in recent years have resulted in significant progress in identifying several Ca(2+)-sensing proteins in plants and in understanding the function of some of these Ca(2+)-regulated proteins at the cellular and whole plant level. As more and more Ca(2+)-sensing proteins are identified it is becoming apparent that plants have several unique Ca(2+)-sensing proteins and that the downstream components of Ca(2+) signaling in plants have novel features and regulatory mechanisms. Although the mechanisms by which Ca(2+) regulates diverse biochemical and molecular processes and eventually physiological processes in response to diverse signals are beginning to be understood, recent studies have raised many interesting questions. Despite the fact that Ca(2+) sensing proteins are being identified at a rapid pace, progress on the function(s) of many of them is limited. Studies on plant 'signalome' - the identification of all signaling components in all messengers mediated transduction pathways, analysis of their function and regulation, and cross talk among these components - should help in understanding the inner workings of plant cell responses to diverse signals. New functional genomics approaches such as reverse genetics, microarray analyses coupled with in vivo protein-protein interaction studies and proteomics should not only permit functional analysis of various components in Ca(2+) signaling but also enable identification of a complex network of interactions.
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Affiliation(s)
- A S.N. Reddy
- Department of Biology and Program in Cell and Molecular Biology, Colorado State University, 80523, Fort Collins, CO, USA
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32
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van Der Luit AH, Olivari C, Haley A, Knight MR, Trewavas AJ. Distinct calcium signaling pathways regulate calmodulin gene expression in tobacco. PLANT PHYSIOLOGY 1999; 121:705-14. [PMID: 10557218 PMCID: PMC59432 DOI: 10.1104/pp.121.3.705] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/1999] [Accepted: 07/20/1999] [Indexed: 05/17/2023]
Abstract
Cold shock and wind stimuli initiate Ca(2+) transients in transgenic tobacco (Nicotiana plumbaginifolia) seedlings (named MAQ 2.4) containing cytoplasmic aequorin. To investigate whether these stimuli initiate Ca(2+) pathways that are spatially distinct, stress-induced nuclear and cytoplasmic Ca(2+) transients and the expression of a stress-induced calmodulin gene were compared. Tobacco seedlings were transformed with a construct that encodes a fusion protein between nucleoplasmin (a major oocyte nuclear protein) and aequorin. Immunocytochemical evidence indicated targeting of the fusion protein to the nucleus in these plants, which were named MAQ 7.11. Comparison between MAQ 7.11 and MAQ 2.4 seedlings confirmed that wind stimuli and cold shock invoke separate Ca(2+) signaling pathways. Partial cDNAs encoding two tobacco calmodulin genes, NpCaM-1 and NpCaM-2, were identified and shown to have distinct nucleotide sequences that encode identical polypeptides. Expression of NpCaM-1, but not NpCaM-2, responded to wind and cold shock stimulation. Comparison of the Ca(2+) dynamics with NpCaM-1 expression after stimulation suggested that wind-induced NpCaM-1 expression is regulated by a Ca(2+) signaling pathway operational predominantly in the nucleus. In contrast, expression of NpCaM-1 in response to cold shock is regulated by a pathway operational predominantly in the cytoplasm.
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Affiliation(s)
- A H van Der Luit
- Institute for Molecular Cell Biology, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands.
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33
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Taybi T, Cushman JC. Signaling events leading to crassulacean acid metabolism induction in the common ice plant. PLANT PHYSIOLOGY 1999; 121:545-56. [PMID: 10517846 PMCID: PMC59417 DOI: 10.1104/pp.121.2.545] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/1999] [Accepted: 06/22/1999] [Indexed: 05/22/2023]
Abstract
A rapid, semiquantitative reverse transcriptase-polymerase chain reaction assay was developed to investigate signal transduction events involved in the induction of Crassulacean acid metabolism (CAM) in detached common ice plant (Mesembryanthemum crystallinum) leaves. Transcript abundance of Ppc1, a gene encoding the CAM-specific isoform of phosphoenolpyruvate carboxylase, increased rapidly in response to osmotic stress (dehydration and mannitol), ionic stress (NaCl), and exogenous abscisic acid treatment, but failed to accumulate in response to exogenous cytokinin or methyl jasmonate. Stress-induced accumulation of Ppc1, GapC1, and Mdh1 transcripts was inhibited by pretreating leaves with the calcium chelator ethyleneglycol-bis(aminoethyl ether)-N,N'-tetraacetic acid, suggesting that extracellular calcium participates in signaling events leading to CAM induction. Treatment of unstressed detached leaves with ionomycin, a Ca(2+) ionophore, and thapsigargin, a Ca(2+)-ATPase inhibitor, enhanced Ppc1 transcript accumulation, indicating that elevations in cytosolic [Ca(2+)] are likely to participate in signaling CAM induction. Inhibitors of Ca(2+)- or calmodulin-dependent protein kinases (N-[6-aminohexyl]-5-chloro-1-napthalenesulfonamide, Lavendustin C) and protein phosphatase 1 and 2A (okadaic acid) activity suppressed Ppc1 transcript accumulation in response to ionic and osmotic stresses, as well as abscisic acid treatment. These results suggest that both protein phosphorylation and dephosphorylation events participate in signaling during CAM induction. In contrast, pretreatment with cyclosporin A or ascomycin, inhibitors of protein phosphatase 2B activity, stimulated Ppc1 gene expression either directly or indirectly through promoting water loss.
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Affiliation(s)
- T Taybi
- Department of Biochemistry and Molecular Biology, 147 Noble Research Center, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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34
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Abstract
C4 plants, including maize, Flaveria, amaranth, sorghum, and an amphibious sedge Eleocharis vivipara, have been employed to elucidate the molecular mechanisms and signaling pathways that control C4 photosynthesis gene expression. Current evidence suggests that pre-existing genes were recruited for the C4 pathway after acquiring potent and surprisingly diverse regulatory elements. This review emphasizes recent advances in our understanding of the creation of C4 genes, the activities of the C4 gene promoters consisting of synergistic and combinatorial enhancers and silencers, the use of 5' and 3' untranslated regions for transcriptional and posttranscriptional regulations, and the function of novel transcription factors. The research has also revealed new insights into unique or universal mechanisms underlying cell-type specificity, coordinate nuclear-chloroplast actions, hormonal, metabolic, stress and light responses, and the control of enzymatic activities by phosphorylation and reductive processes.
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Affiliation(s)
- Jen Sheen
- Department of Molecular Biology, Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; e-mail:
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35
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Meagher RB, McKinney EC, Kandasamy MK. Isovariant dynamics expand and buffer the responses of complex systems: the diverse plant actin gene family. THE PLANT CELL 1999. [PMID: 10368172 DOI: 10.2307/3870793] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Affiliation(s)
- R B Meagher
- Genetics Department, Life Sciences Building, University of Georgia, Athens, Georgia 30602-7223, USA.
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36
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Meagher RB, McKinney EC, Kandasamy MK. Isovariant dynamics expand and buffer the responses of complex systems: the diverse plant actin gene family. THE PLANT CELL 1999; 11:995-1006. [PMID: 10368172 PMCID: PMC1464670 DOI: 10.1105/tpc.11.6.995] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Affiliation(s)
- R B Meagher
- Genetics Department, Life Sciences Building, University of Georgia, Athens, Georgia 30602-7223, USA.
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37
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Liao B, Paschal BM, Luby-Phelps K. Mechanism of Ca2+-dependent nuclear accumulation of calmodulin. Proc Natl Acad Sci U S A 1999; 96:6217-22. [PMID: 10339568 PMCID: PMC26862 DOI: 10.1073/pnas.96.11.6217] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The intracellular Ca2+ receptor calmodulin (CaM) coordinates responses to extracellular stimuli by modulating the activities of its various binding proteins. Recent reports suggest that, in addition to its familiar functions in the cytoplasm, CaM may be directly involved in rapid signaling between cytoplasm and nucleus. Here we show that Ca2+-dependent nuclear accumulation of CaM can be reconstituted in permeabilized cells. Accumulation was blocked by M13, a CaM antagonist peptide, but did not require cytosolic factors or an ATP regenerating system. Ca2+-dependent influx of CaM into nuclei was not blocked by inhibitors of nuclear localization signal-mediated nuclear import in either permeabilized or intact cells. Fluorescence recovery after photobleaching studies of CaM in intact cells showed that influx is a first-order process with a rate constant similar to that of a freely diffusible control molecule (20-kDa dextran). Studies of CaM efflux from preloaded nuclei in permeablized cells revealed the existence of three classes of nuclear binding sites that are distinguished by their Ca2+-dependence and affinity. At high [Ca2+], efflux was enhanced by addition of a high affinity CaM-binding protein outside the nucleus. These data suggest that CaM diffuses freely through nuclear pores and that CaM-binding proteins in the nucleus act as a sink for Ca2+-CaM, resulting in accumulation of CaM in the nucleus on elevation of intracellular free Ca2+.
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Affiliation(s)
- B Liao
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, TX 75235, USA
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38
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Rodríguez-Concepción M, Yalovsky S, Zik M, Fromm H, Gruissem W. The prenylation status of a novel plant calmodulin directs plasma membrane or nuclear localization of the protein. EMBO J 1999; 18:1996-2007. [PMID: 10202162 PMCID: PMC1171284 DOI: 10.1093/emboj/18.7.1996] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Post-translational attachment of isoprenyl groups to conserved cysteine residues at the C-terminus of a number of regulatory proteins is important for their function and subcellular localization. We have identified a novel calmodulin, CaM53, with an extended C-terminal basic domain and a CTIL CaaX-box motif which are required for efficient prenylation of the protein in vitro and in vivo. Ectopic expression of wild-type CaM53 or a non-prenylated mutant protein in plants causes distinct morphological changes. Prenylated CaM53 associates with the plasma membrane, but the non-prenylated mutant protein localizes to the nucleus, indicating a dual role for the C-terminal domain. The subcellular localization of CaM53 can be altered by a block in isoprenoid biosynthesis or sugar depletion, suggesting that CaM53 activates different targets in response to metabolic changes. Thus, prenylation of CaM53 appears to be a novel mechanism by which plant cells can coordinate Ca2+ signaling with changes in metabolic activities.
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Affiliation(s)
- M Rodríguez-Concepción
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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39
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Shah J, Klessig DF. Salicylic acid: signal perception and transduction. BIOCHEMISTRY AND MOLECULAR BIOLOGY OF PLANT HORMONES 1999. [DOI: 10.1016/s0167-7306(08)60503-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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40
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Busk PK, Borrell A, Kizis D, Pagès M. Abscisic acid perception and transduction. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0167-7306(08)60502-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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41
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Abstract
Calmodulin is a small Ca2+-binding protein that acts to transduce second messenger signals into a wide array of cellular responses. Plant calmodulins share many structural and functional features with their homologs from animals and yeast, but the expression of multiple protein isoforms appears to be a distinctive feature of higher plants. Calmodulin acts by binding to short peptide sequences within target proteins, thereby inducing structural changes, which alters their activities in response to changes in intracellular Ca2+ concentration. The spectrum of plant calmodulin-binding proteins shares some overlap with that found in animals, but a growing number of calmodulin-regulated proteins in plants appear to be unique. Ca2+-binding and enzymatic activation properties of calmodulin are discussed emphasizing the functional linkages between these processes and the diverse pathways that are dependent on Ca2+ signaling.
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Affiliation(s)
- Raymond E. Zielinski
- Department of Plant Biology and the Physiological and Molecular Plant Biology Program, University of Illinois, 1201 W. Gregory Drive, Urbana, Illinois 61801; e-mail:
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