151
|
Wang L, Hua D, He J, Duan Y, Chen Z, Hong X, Gong Z. Auxin Response Factor2 (ARF2) and its regulated homeodomain gene HB33 mediate abscisic acid response in Arabidopsis. PLoS Genet 2011; 7:e1002172. [PMID: 21779177 PMCID: PMC3136439 DOI: 10.1371/journal.pgen.1002172] [Citation(s) in RCA: 169] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/19/2011] [Indexed: 01/10/2023] Open
Abstract
The phytohormone abscisic acid (ABA) is an important regulator of plant development and response to environmental stresses. In this study, we identified two ABA overly sensitive mutant alleles in a gene encoding Auxin Response Factor2 (ARF2). The expression of ARF2 was induced by ABA treatment. The arf2 mutants showed enhanced ABA sensitivity in seed germination and primary root growth. In contrast, the primary root growth and seed germination of transgenic plants over-expressing ARF2 are less inhibited by ABA than that of the wild type. ARF2 negatively regulates the expression of a homeodomain gene HB33, the expression of which is reduced by ABA. Transgenic plants over-expressing HB33 are more sensitive, while transgenic plants reducing HB33 by RNAi are more resistant to ABA in the seed germination and primary root growth than the wild type. ABA treatment altered auxin distribution in the primary root tips and made the relative, but not absolute, auxin accumulation or auxin signal around quiescent centre cells and their surrounding columella stem cells to other cells stronger in arf2-101 than in the wild type. These results indicate that ARF2 and HB33 are novel regulators in the ABA signal pathway, which has crosstalk with auxin signal pathway in regulating plant growth. Abscisic acid is a phytohormone that regulates many aspects in plant growth and development and response to different biotic and abiotic stresses. Research on ABA inhibiting seed germination, controlling stomatal movement, and regulating gene expression has been widely performed. However, the molecular mechanism for ABA regulating root growth is not well known. We have set up a genetic screen by using ABA inhibiting root growth to identify ABA related mutants and to dissect the molecular mechanism of ABA regulating root growth. In this study, we identified two new mutant alleles that are defective in ARF2 gene. ARF2 is a transcriptional suppressor that has been found to be involved in ethylene, auxin, and brassinosteroid pathway to control plant growth and development. Our study indicates that ARF2 is an ABA responsive regulator that functions in both seed germination and primary root growth. ARF2 directly regulates the expression of a homeodomain gene HB33. We demonstrate that ABA treatment reduces the cell division and alters auxin distribution more in arf2 mutant than in the wild type, suggesting an important mechanism in ABA inhibiting the primary root growth through mediating cell division in root tips.
Collapse
Affiliation(s)
- Li Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Deping Hua
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Junna He
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Ying Duan
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhizhong Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xuhui Hong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
- China Agricultural University–Purdue University Joint Research Center, Beijing, China
- National Center for Plant Gene Research, Beijing, China
- * E-mail:
| |
Collapse
|
152
|
Takezawa D, Komatsu K, Sakata Y. ABA in bryophytes: how a universal growth regulator in life became a plant hormone? JOURNAL OF PLANT RESEARCH 2011; 124:437-53. [PMID: 21416316 DOI: 10.1007/s10265-011-0410-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 02/11/2011] [Indexed: 05/03/2023]
Abstract
Abscisic acid (ABA) is not a plant-specific compound but one found in organisms across kingdoms from bacteria to animals, suggesting that it is a ubiquitous and versatile substance that can modulate physiological functions of various organisms. Recent studies have shown that plants developed an elegant system for ABA sensing and early signal transduction mechanisms to modulate responses to environmental stresses for survival in terrestrial conditions. ABA-induced increase in stress tolerance has been reported not only in vascular plants but also in non-vascular bryophytes. Since bryophytes are the key group of organisms in the context of plant evolution, clarification of their ABA-dependent processes is important for understanding evolutionary adaptation of land plants. Molecular approaches using Physcomitrella patens have revealed that ABA plays a role in dehydration stress tolerance in mosses, which comprise a major group of bryophytes. Furthermore, we recently reported that signaling machinery for ABA responses is also conserved in liverworts, representing the most basal members of extant land plant lineage. Conservation of the mechanism for ABA sensing and responses in angiosperms and basal land plants suggests that acquisition of this mechanism for stress tolerance in vegetative tissues was one of the critical evolutionary events for adaptation to the land. This review describes the role of ABA in basal land plants as well as non-land plant organisms and further elaborates on recent progress in molecular studies of model bryophytes by comparative and functional genomic approaches.
Collapse
Affiliation(s)
- Daisuke Takezawa
- Graduate School of Science and Engineering, Institute for Environmental Science and Technology, Saitama University, Saitama 338-8570, Japan.
| | | | | |
Collapse
|
153
|
Joshi-Saha A, Valon C, Leung J. Abscisic acid signal off the STARting block. MOLECULAR PLANT 2011; 4:562-80. [PMID: 21746700 DOI: 10.1093/mp/ssr055] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The year 2009 marked a real turnaround in our understanding of the mode of abscisic acid (ABA) action. Nearly 25 years had elapsed since the first biochemical detection of ABA-binding proteins in the plasmalemma of Vicia guard cells was reported. This recent--and laudable--achievement is owed largely to the discovery of the soluble ABA receptors whose major interacting proteins happen to be some of the most well-established components of earliest steps in ABA signaling. These soluble receptors, with the double name of PYRABACTIN RESISTANCE (PYR) or REGULATORY COMPONENT OF ABA RECEPTOR (RCAR), are a family of Arabidopsis proteins of about 150-200 amino acids that share a conserved START domain. The ABA signal transduction circuitry under non-stress conditions is muted by the clade A protein phosphatases 2C (PP2C) (notably HAB1, ABI1, and ABI2). During the initial steps of ABA signaling, the binding of the hormone to the receptor induces a conformational change in the latter that allows it to sequester the PP2Cs. This excludes them from the negative regulation of the downstream ABA-activated kinases (OST1/SnRK2.6/SRK2E, SnRK2.2, and SnRK2.3), thus unleashing the pathway by freeing them to phosphorylate downstream targets that now include several b-ZIP transcription factors, ion channels (SLAC1, KAT1), and a NADPH oxidase (AtrbohF). The discovery of this family of soluble receptors and the rich insight already gained from structural studies of their complexes with different isoforms of ABA, PP2C, and the synthetic agonist pyrabactin lay the foundation towards rational design of chemical switches that can bolster drought hardiness in plants.
Collapse
Affiliation(s)
- Archana Joshi-Saha
- Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, UPR2355, 1 Avenue de la Terrasse, Bât. 23, 91198 Gif-sur-Yvette, France
| | | | | |
Collapse
|
154
|
Hayashi M, Inoue SI, Takahashi K, Kinoshita T. Immunohistochemical detection of blue light-induced phosphorylation of the plasma membrane H+-ATPase in stomatal guard cells. PLANT & CELL PHYSIOLOGY 2011; 52:1238-48. [PMID: 21666226 DOI: 10.1093/pcp/pcr072] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Blue light (BL) receptor phototropins activate the plasma membrane H(+)-ATPase in guard cells through phosphorylation of a penultimate threonine and subsequent binding of the 14-3-3 protein to the phosphorylated C-terminus of H⁺-ATPase, mediating stomatal opening. To date, detection of the phosphorylation level of the guard cell H⁺-ATPase has been performed biochemically using guard cell protoplasts (GCPs). However, preparation of GCPs from Arabidopsis for this purpose requires >5,000 rosette leaves and takes >8 h. Here, we show that BL-induced phosphorylation of guard cell H⁺-ATPase is detected in the epidermis from a single Arabidopsis rosette leaf via an immunohistochemical method using a specific antibody against the phosphorylated penultimate threonine of H⁺-ATPase. BL-induced phosphorylation of the H⁺-ATPase was detected immunohistochemically in the wild type, but not in a phot1-5 phot2-1 double mutant. Moreover, we found that physiological concentrations of the phytohormone ABA completely inhibited BL-induced phosphorylation of guard cell H⁺-ATPase in the epidermis, and that inhibition by ABA in the epidermis is more sensitive than in GCPs. These results indicate that this immunohistochemical method is very useful for detecting the phosphorylation status of guard cell H⁺-ATPase. Thus, we applied this technique to ABA-insensitive mutants (abi1-1, abi2-1 and ost1-2) and found that ABA had no effect on BL-induced phosphorylation in these mutants. These results indicate that inhibition of BL-induced phosphorylation of guard cell H⁺-ATPase by ABA is regulated by ABI1, ABI2 and OST1, which are known to be early ABA signaling components for a wide range of ABA responses in plants.
Collapse
Affiliation(s)
- Maki Hayashi
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | | | | | | |
Collapse
|
155
|
Bazin J, Langlade N, Vincourt P, Arribat S, Balzergue S, El-Maarouf-Bouteau H, Bailly C. Targeted mRNA oxidation regulates sunflower seed dormancy alleviation during dry after-ripening. THE PLANT CELL 2011; 23:2196-208. [PMID: 21642546 PMCID: PMC3160027 DOI: 10.1105/tpc.111.086694] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 05/18/2011] [Accepted: 05/24/2011] [Indexed: 05/18/2023]
Abstract
After-ripening is the mechanism by which dormant seeds become nondormant during their dry storage after harvest. The absence of free water in mature seeds does not allow detectable metabolism; thus, the processes associated with dormancy release under these conditions are largely unknown. We show here that sunflower (Helianthus annuus) seed alleviation of dormancy during after-ripening is associated with mRNA oxidation and that this oxidation is prevented when seeds are maintained dormant. In vitro approaches demonstrate that mRNA oxidation results in artifacts in cDNA-amplified fragment length polymorphim analysis and alters protein translation. The oxidation of transcripts is not random but selective, and, using microarrays, we identified 24 stored mRNAs that became highly oxidized during after-ripening. Oxidized transcripts mainly correspond to genes involved in responses to stress and in cell signaling. Among them, protein phosphatase 2C PPH1, mitogen-activated protein kinase phosphatase 1, and phenyl ammonia lyase 1 were identified. We propose that targeted mRNA oxidation during dry after-ripening of dormant seeds could be a process that governs cell signaling toward germination in the early steps of seed imbibition.
Collapse
Affiliation(s)
- Jérémie Bazin
- UR5 EAC7180 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Université Paris 06, 75005 Paris, France
| | - Nicolas Langlade
- Laboratoire Interactions Plantes Microorganismes, Institut National de la Recherche Agronomique, 31326 Castanet Tolosan, France
| | - Patrick Vincourt
- Laboratoire Interactions Plantes Microorganismes, Institut National de la Recherche Agronomique, 31326 Castanet Tolosan, France
| | - Sandrine Arribat
- Equipe Génomique Fonctionnelle d’Arabidopsis, Unité de Recherche en Génomique Végétale, Unité Mixte de Recherche, Institut National de la Recherche Agronomique 1165, Université d’Evry Val d’Essonne, ERL Centre National de la Recherche Scientifique 8196, F-91057 Evry Cedex, France
| | - Sandrine Balzergue
- Equipe Génomique Fonctionnelle d’Arabidopsis, Unité de Recherche en Génomique Végétale, Unité Mixte de Recherche, Institut National de la Recherche Agronomique 1165, Université d’Evry Val d’Essonne, ERL Centre National de la Recherche Scientifique 8196, F-91057 Evry Cedex, France
| | - Hayat El-Maarouf-Bouteau
- UR5 EAC7180 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Université Paris 06, 75005 Paris, France
| | - Christophe Bailly
- UR5 EAC7180 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Université Paris 06, 75005 Paris, France
- Address correspondence to
| |
Collapse
|
156
|
Dupeux F, Antoni R, Betz K, Santiago J, Gonzalez-Guzman M, Rodriguez L, Rubio S, Park SY, Cutler SR, Rodriguez PL, Márquez JA. Modulation of abscisic acid signaling in vivo by an engineered receptor-insensitive protein phosphatase type 2C allele. PLANT PHYSIOLOGY 2011; 156:106-16. [PMID: 21357183 PMCID: PMC3091035 DOI: 10.1104/pp.110.170894] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 02/28/2011] [Indexed: 05/20/2023]
Abstract
The plant hormone abscisic acid (ABA) plays a crucial role in the control of the stress response and the regulation of plant growth and development. ABA binding to PYRABACTIN RESISTANCE1 (PYR1)/PYR1-LIKE (PYL)/REGULATORY COMPONENTS OF ABA RECEPTORS intracellular receptors leads to inhibition of key negative regulators of ABA signaling, i.e. clade A protein phosphatases type 2C (PP2Cs) such as ABA-INSENSITIVE1 and HYPERSENSITIVE TO ABA1 (HAB1), causing the activation of the ABA signaling pathway. To gain further understanding on the mechanism of hormone perception, PP2C inhibition, and its implications for ABA signaling, we have performed a structural and functional analysis of the PYR1-ABA-HAB1 complex. Based on structural data, we generated a gain-of-function mutation in a critical residue of the phosphatase, hab1(W385A), which abolished ABA-dependent receptor-mediated PP2C inhibition without impairing basal PP2C activity. As a result, hab1(W385A) caused constitutive inactivation of the protein kinase OST1 even in the presence of ABA and PYR/PYL proteins, in contrast to the receptor-sensitive HAB1, and therefore hab1(W385A) qualifies as a hypermorphic mutation. Expression of hab1(W385A) in Arabidopsis (Arabidopsis thaliana) plants leads to a strong, dominant ABA insensitivity, which demonstrates that this conserved tryptophan residue can be targeted for the generation of dominant clade A PP2C alleles. Moreover, our data highlight the critical role of molecular interactions mediated by tryptophan-385 equivalent residues for clade A PP2C function in vivo and the mechanism of ABA perception and signaling.
Collapse
|
157
|
Somyong S, Munkvold JD, Tanaka J, Benscher D, Sorrells ME. Comparative genetic analysis of a wheat seed dormancy QTL with rice and Brachypodium identifies candidate genes for ABA perception and calcium signaling. Funct Integr Genomics 2011; 11:479-90. [PMID: 21468744 DOI: 10.1007/s10142-011-0219-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 03/05/2011] [Accepted: 03/12/2011] [Indexed: 11/24/2022]
Abstract
Wheat preharvest sprouting (PHS) occurs when seed germinates on the plant before harvest resulting in reduced grain quality. In wheat, PHS susceptibility is correlated with low levels of seed dormancy. A previous mapping of quantitative trait loci (QTL) revealed a major PHS/seed dormancy QTL, QPhs.cnl-2B.1, located on wheat chromosome 2B. A comparative genetic study with the related grass species rice (Oryza sativa L.) and Brachypodium distachyon at the homologous region to the QPhs.cnl-2B.1 interval was used to identify the candidate genes for marker development and subsequent fine mapping. Expressed sequence tags and a comparative mapping were used to design 278 primer pairs, of which 22 produced polymorphic amplicons that mapped to the group 2 chromosomes. Fourteen mapped to chromosome 2B, and ten were located in the QTL interval. A comparative analysis revealed good macrocollinearity between the PHS interval and 3 million base pair (mb) region on rice chromosomes 7 and 3, and a 2.7-mb region on Brachypodium Bd1. The comparative intervals in rice were found to contain three previously identified rice seed dormancy QTL. Further analyses of the interval in rice identified genes that are known to play a role in seed dormancy, including a homologue for the putative Arabidopsis ABA receptor ABAR/GUN5. Additional candidate genes involved in calcium signaling were identified and were placed in a functional protein association network that includes additional proteins critical for ABA signaling and germination. This study provides promising candidate genes for seed dormancy in both wheat and rice as well as excellent molecular markers for further comparative and fine mapping.
Collapse
Affiliation(s)
- Suthasinee Somyong
- National Center for Genetic Engineering and Biotechnology, Pathumthani, Thailand
| | | | | | | | | |
Collapse
|
158
|
Gao SQ, Chen M, Xu ZS, Zhao CP, Li L, Xu HJ, Tang YM, Zhao X, Ma YZ. The soybean GmbZIP1 transcription factor enhances multiple abiotic stress tolerances in transgenic plants. PLANT MOLECULAR BIOLOGY 2011; 75:537-53. [PMID: 21331631 DOI: 10.1007/s11103-011-9738-4] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2010] [Accepted: 01/15/2011] [Indexed: 05/18/2023]
Abstract
Abscisic acid (ABA)-responsive element binding proteins (AREBs) are basic domain/leucine zipper transcription factors that bind to the ABA-responsive element (ABRE) in the promoter regions of ABA-inducible genes in plants. A novel bZIP transcription factor gene, GmbZIP1, encoding 438 amino acids with a conserved bZIP domain composed of 60 amino acids was isolated from salt-tolerant soybean cv. Tiefeng 8. Southern blotting showed that only one copy was present in the soybean genome. Phylogenetic analyses showed that GmbZIP1 belonged to the AREB subfamily of the bZIP family and was most closely related to AtABF2 and OsTRAB1. The expression of GmbZIP1 was highly induced by ABA, drought, high salt and low temperature; and GmbZIP1 was expressed in soybean roots, stems and leaves under different stress conditions. GmbZIP1 was localized inside the nuclei of transformed onion epidermal cells. Overexpression of GmbZIP1 enhanced the responses of transgenic plants to ABA and triggered stomatal closure under stresses, potentially leading to improved tolerances to several abiotic stresses such as high salt, low temperature and drought in transgenic plants. Furthermore, overexpression of GmbZIP1 affected the expression of some ABA or stress-related genes involved in regulating stomatal closure in Arabidopsis under ABA, drought and high salt stress conditions. A few AREB elements were detected in the promoter region of those ABA or stress-related genes, suggesting that GmbZIP1 regulates the ABA response or stomatal closure mediated by those downstream genes in transgenic Arabidopsis. Moreover, GmbZIP1 was used to improve the drought tolerance trait of Chinese wheat varieties BS93. Functional analysis showed that overexpression of GmbZIP1 enhanced the drought tolerance of transgenic wheat, and transcripts of GmbZIP1 were detected in transgenic wheat using RT-PCR. In addition, GmbZIP1 overexpression did not result in growth retardation in all transgenic plants, suggesting that GmbZIP1 may be a valuable genetic resource for engineering stress tolerance of crops.
Collapse
MESH Headings
- Arabidopsis/genetics
- Basic-Leucine Zipper Transcription Factors/genetics
- Basic-Leucine Zipper Transcription Factors/physiology
- Blotting, Northern
- Blotting, Southern
- Cold-Shock Response/genetics
- Dehydration/genetics
- Gene Expression Regulation, Plant/genetics
- Gene Expression Regulation, Plant/physiology
- Genes, Plant/genetics
- Genes, Plant/physiology
- Phylogeny
- Plant Transpiration/genetics
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Salt-Tolerant Plants/genetics
- Soybean Proteins/genetics
- Soybean Proteins/physiology
- Glycine max/genetics
- Stress, Physiological/genetics
- Stress, Physiological/physiology
- Triticum/genetics
Collapse
Affiliation(s)
- Shi-Qing Gao
- National Key Facility for Crop Genetic Resources and Genetic Improvement (NFCRI), Key Laboratory of Crop Genetics and Breeding, Ministry of Agriculture, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China
| | | | | | | | | | | | | | | | | |
Collapse
|
159
|
Jiang T, Zhang XF, Wang XF, Zhang DP. Arabidopsis 3-ketoacyl-CoA thiolase-2 (KAT2), an enzyme of fatty acid β-oxidation, is involved in ABA signal transduction. PLANT & CELL PHYSIOLOGY 2011; 52:528-38. [PMID: 21257607 DOI: 10.1093/pcp/pcr008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The phytohormone ABA plays an important role in plant development and adaptation to diverse environmental stresses. Many of the components involved in ABA signaling remain to be discovered, and knowledge of these is needed to understand fully the highly complex ABA signaling network. Here, we report that an enzyme catalyzing β-oxidation of fatty acids, 3-ketoacyl-CoA thiolase-2 (KAT2/PED1/PKT3) (EC 2.3.1.16), is involved in ABA signaling. We provide genetic evidence that KAT2 positively regulates ABA signaling in all the major ABA responses, including ABA-induced inhibition of seed germination and post-germination growth arrest, and ABA-induced stomatal closure and stomatal opening inhibition in Arabidopsis thaliana. KAT2 was shown to be important for reactive oxygen species (ROS) production in response to ABA, suggesting that KAT2 regulates ABA signaling at least partly through modulating ROS homeostasis in plant cells. Additionally, we provide data suggesting that KAT2 may function downstream of an important WRKY transcription repressor WRKY40, which may link KAT2 with the ABA receptor ABAR/CHLH-mediated signaling.
Collapse
Affiliation(s)
- Tao Jiang
- College of Biological Sciences, China Agricultural University, Beijing 100094, PR China
| | | | | | | |
Collapse
|
160
|
Zhang Z, Zhang S, Zhang Y, Wang X, Li D, Li Q, Yue M, Li Q, Zhang YE, Xu Y, Xue Y, Chong K, Bao S. Arabidopsis floral initiator SKB1 confers high salt tolerance by regulating transcription and pre-mRNA splicing through altering histone H4R3 and small nuclear ribonucleoprotein LSM4 methylation. THE PLANT CELL 2011; 23:396-411. [PMID: 21258002 PMCID: PMC3051234 DOI: 10.1105/tpc.110.081356] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 11/15/2010] [Accepted: 01/04/2011] [Indexed: 05/19/2023]
Abstract
Plants adapt their growth and development in response to perceived salt stress. Although DELLA-dependent growth restraint is thought to be an integration of the plant's response to salt stress, little is known about how histone modification confers salt stress and, in turn, affects development. Here, we report that floral initiator Shk1 kinase binding protein1 (SKB1) and histone4 arginine3 (H4R3) symmetric dimethylation (H4R3sme2) integrate responses to plant developmental progress and salt stress. Mutation of SKB1 results in salt hypersensitivity, late flowering, and growth retardation. SKB1 associates with chromatin and thereby increases the H4R3sme2 level to suppress the transcription of FLOWERING LOCUS C (FLC) and a number of stress-responsive genes. During salt stress, the H4R3sme2 level is reduced, as a consequence of SKB1 disassociating from chromatin to induce the expression of FLC and the stress-responsive genes but increasing the methylation of small nuclear ribonucleoprotein Sm-like4 (LSM4). Splicing defects are observed in the skb1 and lsm4 mutants, which are sensitive to salt. We propose that SKB1 mediates plant development and the salt response by altering the methylation status of H4R3sme2 and LSM4 and linking transcription to pre-mRNA splicing.
Collapse
Affiliation(s)
- Zhaoliang Zhang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- Graduate University of the Chinese Academy of Sciences, Beijing 100039, China
| | - Shupei Zhang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ya Zhang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xin Wang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Dan Li
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiuling Li
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- Graduate University of the Chinese Academy of Sciences, Beijing 100039, China
| | - Minghui Yue
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- Graduate University of the Chinese Academy of Sciences, Beijing 100039, China
| | - Qun Li
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu-e Zhang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yunyuan Xu
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yongbiao Xue
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- National Plant Gene Research Centre, Beijing 100101, China
| | - Kang Chong
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- National Plant Gene Research Centre, Beijing 100101, China
| | - Shilai Bao
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- Address correspondence to
| |
Collapse
|
161
|
Muñoz-Bertomeu J, Bermúdez MA, Segura J, Ros R. Arabidopsis plants deficient in plastidial glyceraldehyde-3-phosphate dehydrogenase show alterations in abscisic acid (ABA) signal transduction: interaction between ABA and primary metabolism. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:1229-39. [PMID: 21068209 PMCID: PMC3022406 DOI: 10.1093/jxb/erq353] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 10/11/2010] [Accepted: 10/14/2010] [Indexed: 05/18/2023]
Abstract
Abscisic acid (ABA) controls plant development and regulates plant responses to environmental stresses. A role for ABA in sugar regulation of plant development has also been well documented although the molecular mechanisms connecting the hormone with sugar signal transduction pathways are not well understood. In this work it is shown that Arabidopsis thaliana mutants deficient in plastidial glycolytic glyceraldehyde-3-phosphate dehydrogenase (gapcp1gapcp2) are ABA insensitive in growth, stomatal closure, and germination assays. The ABA levels of gapcp1gapcp2 were normal, suggesting that the ABA signal transduction pathway is impaired in the mutants. ABA modified gapcp1gapcp2 gene expression, but the mutant response to the hormone differed from that observed in wild-type plants. The gene expression of the transcription factor ABI4, involved in both sugar and ABA signalling, was altered in gapcp1gapcp2, suggesting that their ABA insensitivity is mediated, at least partially, through this transcriptional regulator. Serine supplementation was able partly to restore the ABA sensitivity of gapcp1gapcp2, indicating that amino acid homeostasis and/or serine metabolism may also be important determinants in the connections of ABA with primary metabolism. Overall, these studies provide new insights into the links between plant primary metabolism and ABA signalling, and demonstrate the importance of plastidial glycolytic glyceraldehyde-3-phosphate dehydrogenase in these interactions.
Collapse
Affiliation(s)
- Jesús Muñoz-Bertomeu
- Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València. Av. Vicent Andrés Estellés S/N, 46100 Burjassot (Valencia), Spain
| | - María Angeles Bermúdez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and University of Seville, Avda. Américo Vespucio, 49, 41092 Sevilla, Spain
| | - Juan Segura
- Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València. Av. Vicent Andrés Estellés S/N, 46100 Burjassot (Valencia), Spain
| | - Roc Ros
- Departament de Biologia Vegetal, Facultat de Farmàcia, Universitat de València. Av. Vicent Andrés Estellés S/N, 46100 Burjassot (Valencia), Spain
| |
Collapse
|
162
|
The CBL–CIPK Network for Decoding Calcium Signals in Plants. CODING AND DECODING OF CALCIUM SIGNALS IN PLANTS 2011. [DOI: 10.1007/978-3-642-20829-4_12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
163
|
Chen YH, Hu L, Punta M, Bruni R, Hillerich B, Kloss B, Rost B, Love J, Siegelbaum SA, Hendrickson WA. Homologue structure of the SLAC1 anion channel for closing stomata in leaves. Nature 2010; 467:1074-80. [PMID: 20981093 PMCID: PMC3548404 DOI: 10.1038/nature09487] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Accepted: 09/10/2010] [Indexed: 01/17/2023]
Abstract
The plant SLAC1 anion channel controls turgor pressure in the aperture-defining guard cells of plant stomata, thereby regulating exchange of water vapor and photosynthetic gases in response to environmental signals such as drought or high levels of carbon dioxide. We determined the crystal structure of a bacterial homolog of SLAC1 at 1.20Å resolution, and we have used structure-inspired mutagenesis to analyze the conductance properties of SLAC1 channels. SLAC1 is a symmetric trimer composed from quasi-symmetric subunits, each having ten transmembrane helices arranged from helical hairpin pairs to form a central five-helix transmembrane pore that is gated by an extremely conserved phenylalanine residue. Conformational features suggest a mechanism for control of gating by kinase activation, and electrostatic features of the pore coupled with electrophysiological characteristics suggest that selectivity among different anions is largely a function of the energetic cost of ion dehydration.
Collapse
Affiliation(s)
- Yu-Hang Chen
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
164
|
Sirichandra C, Davanture M, Turk BE, Zivy M, Valot B, Leung J, Merlot S. The Arabidopsis ABA-activated kinase OST1 phosphorylates the bZIP transcription factor ABF3 and creates a 14-3-3 binding site involved in its turnover. PLoS One 2010; 5:e13935. [PMID: 21085673 PMCID: PMC2978106 DOI: 10.1371/journal.pone.0013935] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 10/21/2010] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Genetic evidence in Arabidopsis thaliana indicates that members of the Snf1-Related Kinases 2 family (SnRK2) are essential in mediating various stress-adaptive responses. Recent reports have indeed shown that one particular member, Open Stomata (OST)1, whose kinase activity is stimulated by the stress hormone abscisic acid (ABA), is a direct target of negative regulation by the core ABA co-receptor complex composed of PYR/PYL/RCAR and clade A Protein Phosphatase 2C (PP2C) proteins. METHODOLOGY/PRINCIPAL FINDINGS Here, the substrate preference of OST1 was interrogated at a genome-wide scale. We phosphorylated in vitro a bank of semi-degenerate peptides designed to assess the relative phosphorylation efficiency on a positionally fixed serine or threonine caused by systematic changes in the flanking amino acid sequence. Our results designate the ABA-responsive-element Binding Factor 3 (ABF3), which controls part of the ABA-regulated transcriptome, as a genuine OST1 substrate. Bimolecular Fluorescence Complementation experiments indicate that ABF3 interacts directly with OST1 in the nuclei of living plant cells. In vitro, OST1 phosphorylates ABF3 on multiple LXRXXpS/T preferred motifs including T451 located in the midst of a conserved 14-3-3 binding site. Using an antibody sensitive to the phosphorylated state of the preferred motif, we further show that ABF3 is phosphorylated on at least one such motif in response to ABA in vivo and that phospho-T451 is important for stabilization of ABF3. CONCLUSIONS/SIGNIFICANCE All together, our results suggest that OST1 phosphorylates ABF3 in vivo on T451 to create a 14-3-3 binding motif. In a wider physiological context, we propose that the long term responses to ABA that require sustained gene expression is, in part, mediated by the stabilization of ABFs driven by ABA-activated SnRK2s.
Collapse
Affiliation(s)
| | - Marlène Davanture
- UMR Génétique Végétale (UMR 0320/UMR 8120), Plate-Forme de Protéomique PAPPSO, INRA, Université Paris-Sud 11, CNRS, AgroParistTech, Gif-sur-Yvette, France
- IFR87 La plante et son environnement, Université Paris-Sud 11, INRA, CNRS, AgroParistTech, Gif-sur-Yvette, France
| | - Benjamin E. Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Michel Zivy
- UMR Génétique Végétale (UMR 0320/UMR 8120), Plate-Forme de Protéomique PAPPSO, INRA, Université Paris-Sud 11, CNRS, AgroParistTech, Gif-sur-Yvette, France
| | - Benoît Valot
- UMR Génétique Végétale (UMR 0320/UMR 8120), Plate-Forme de Protéomique PAPPSO, INRA, Université Paris-Sud 11, CNRS, AgroParistTech, Gif-sur-Yvette, France
| | - Jeffrey Leung
- Institut des Sciences du Végétal (UPR 2355), CNRS, Gif-sur-Yvette, France
| | - Sylvain Merlot
- Institut des Sciences du Végétal (UPR 2355), CNRS, Gif-sur-Yvette, France
| |
Collapse
|
165
|
Umezawa T, Nakashima K, Miyakawa T, Kuromori T, Tanokura M, Shinozaki K, Yamaguchi-Shinozaki K. Molecular basis of the core regulatory network in ABA responses: sensing, signaling and transport. PLANT & CELL PHYSIOLOGY 2010; 51:1821-39. [PMID: 20980270 PMCID: PMC2978318 DOI: 10.1093/pcp/pcq156] [Citation(s) in RCA: 563] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 10/12/2010] [Indexed: 05/17/2023]
Abstract
ABA is a major phytohormone that regulates a broad range of plant traits and is especially important for adaptation to environmental conditions. Our understanding of the molecular basis of ABA responses in plants improved dramatically in 2009 and 2010, banner years for ABA research. There are three major components; PYR/PYL/ RCAR (an ABA receptor), type 2C protein phosphatase (PP2C; a negative regulator) and SNF1-related protein kinase 2 (SnRK2; a positive regulator), and they offer a double negative regulatory system, [PYR/PYL/RCAR-| PP2C-| SnRK2]. In the absence of ABA, PP2C inactivates SnRK2 by direct dephosphorylation. In response to environmental or developmental cues, ABA promotes the interaction of PYR/PYL/RCAR and PP2C, resulting in PP2C inhibition and SnRK2 activation. This signaling complex can work in both the nucleus and cytosol, as it has been shown that SnRK2 phosphorylates basic-domain leucine zipper (bZIP) transcription factors or membrane proteins. Several structural analyses of PYR/PYL/RCAR have provided the mechanistic basis for this 'core signaling' model, by elucidating the mechanism of ABA binding of receptors, or the 'gate-latch-lock' mechanism of interaction with PP2C in inhibiting activity. On the other hand, intercellular ABA transport had remained a major issue, as had intracellular ABA signaling. Recently, two plasma membrane-type ABC transporters were identified and shed light on the influx/efflux system of ABA, resolving how ABA is transported from cell to cell in plants. Our knowledge of ABA responses in plants has been greatly expanded from intracellular signaling to intercellular transport of ABA.
Collapse
Affiliation(s)
- Taishi Umezawa
- Gene Discovery Research Group, RIKEN Plant Science Center, 3-1-1 Kouyadai, Tsukuba, Ibaraki, 305-0074 Japan
| | - Kazuo Nakashima
- Biological Resources Division, Japan International Research Center for Agricultural Sciences, Ibaraki, 305-8686 Japan
| | - Takuya Miyakawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan
| | - Takashi Kuromori
- Gene Discovery Research Group, RIKEN Plant Science Center, Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045 Japan
| | - Masaru Tanokura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan
| | - Kazuo Shinozaki
- Gene Discovery Research Group, RIKEN Plant Science Center, 3-1-1 Kouyadai, Tsukuba, Ibaraki, 305-0074 Japan
- Gene Discovery Research Group, RIKEN Plant Science Center, Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045 Japan
- *Corresponding author: E-mail, ; Fax, +81-29-836-9060
| | - Kazuko Yamaguchi-Shinozaki
- Biological Resources Division, Japan International Research Center for Agricultural Sciences, Ibaraki, 305-8686 Japan
- Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan
| |
Collapse
|
166
|
Hubbard KE, Nishimura N, Hitomi K, Getzoff ED, Schroeder JI. Early abscisic acid signal transduction mechanisms: newly discovered components and newly emerging questions. Genes Dev 2010; 24:1695-708. [PMID: 20713515 DOI: 10.1101/gad.1953910] [Citation(s) in RCA: 422] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The plant hormone abscisic acid (ABA) regulates many key processes in plants, including seed germination and development and abiotic stress tolerance, particularly drought resistance. Understanding early events in ABA signal transduction has been a major goal of plant research. The recent identification of the PYRABACTIN (4-bromo-N-[pyridin-2-yl methyl]naphthalene-1-sulfonamide) RESISTANCE (PYR)/REGULATORY COMPONENT OF ABA RECEPTOR (RCAR) family of ABA receptors and their biochemical mode of action represents a major breakthrough in the field. The solving of PYR/RCAR structures provides a context for resolving mechanisms mediating ABA control of protein-protein interactions for downstream signaling. Recent studies show that a pathway based on PYR/RCAR ABA receptors, PROTEIN PHOSPHATASE 2Cs (PP2Cs), and SNF1-RELATED PROTEIN KINASE 2s (SnRK2s) forms the primary basis of an early ABA signaling module. This pathway interfaces with ion channels, transcription factors, and other targets, thus providing a mechanistic connection between the phytohormone and ABA-induced responses. This emerging PYR/RCAR-PP2C-SnRK2 model of ABA signal transduction is reviewed here, and provides an opportunity for testing novel hypotheses concerning ABA signaling. We address newly emerging questions, including the potential roles of different PYR/RCAR isoforms, and the significance of ABA-induced versus constitutive PYR/RCAR-PP2C interactions. We also consider how the PYR/RCAR-PP2C-SnRK2 pathway interfaces with ABA-dependent gene expression, ion channel regulation, and control of small molecule signaling. These exciting developments provide researchers with a framework through which early ABA signaling can be understood, and allow novel questions about the hormone response pathway and possible applications in stress resistance engineering of plants to be addressed.
Collapse
Affiliation(s)
- Katharine E Hubbard
- Center for Molecular Genetics, University of California, San Diego, La Jolla, CA 92093, USA
| | | | | | | | | |
Collapse
|
167
|
Li C, Lv J, Zhao X, Ai X, Zhu X, Wang M, Zhao S, Xia G. TaCHP: a wheat zinc finger protein gene down-regulated by abscisic acid and salinity stress plays a positive role in stress tolerance. PLANT PHYSIOLOGY 2010; 154:211-21. [PMID: 20639406 PMCID: PMC2938152 DOI: 10.1104/pp.110.161182] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The plant response to abiotic stresses involves both abscisic acid (ABA)-dependent and ABA-independent signaling pathways. Here we describe TaCHP, a CHP-rich (for cysteine, histidine, and proline rich) zinc finger protein family gene extracted from bread wheat (Triticum aestivum), is differentially expressed during abiotic stress between the salinity-sensitive cultivar Jinan 177 and its tolerant somatic hybrid introgression cultivar Shanrong No.3. TaCHP expressed in the roots of seedlings at the three-leaf stage, and the transcript localized within the cells of the root tip cortex and meristem. TaCHP transcript abundance was higher in Shanrong No.3 than in Jinan 177, but was reduced by the imposition of salinity or drought stress, as well as by the exogenous supply of ABA. When JN17, a salinity hypersensitive wheat cultivar, was engineered to overexpress TaCHP, its performance in the face of salinity stress was improved, and the ectopic expression of TaCHP in Arabidopsis (Arabidopsis thaliana) also improved the ability of salt tolerance. The expression level of a number of stress reporter genes (AtCBF3, AtDREB2A, AtABI2, and AtABI1) was raised in the transgenic lines in the presence of salinity stress, while that of AtMYB15, AtABA2, and AtAAO3 was reduced in its absence. The presence in the upstream region of the TaCHP open reading frame of the cis-elements ABRE, MYBRS, and MYCRS suggests that it is a component of the ABA-dependent and -independent signaling pathways involved in the plant response to abiotic stress. We suggest that TaCHP enhances stress tolerance via the promotion of CBF3 and DREB2A expression.
Collapse
|
168
|
Liu Y, He J, Chen Z, Ren X, Hong X, Gong Z. ABA overly-sensitive 5 (ABO5), encoding a pentatricopeptide repeat protein required for cis-splicing of mitochondrial nad2 intron 3, is involved in the abscisic acid response in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 63:749-65. [PMID: 20561255 DOI: 10.1111/j.1365-313x.2010.04280.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
To study the molecular mechanism of abscisic acid (ABA) regulation of root development, we screened the root growth of Arabidopsis mutants for sensitivity to ABA. ABA overly-sensitive 5 (ABO5/At1g51965) was identified, and was determined to encode a pentatricopeptide repeat protein required for cis-splicing of mitochondrial nad2 intron 3 (nad2 is one subunit in complex I). Under constant light conditions (24-h light/0-h dark photoperiod), abo5 mutants exhibited various phenotypes and expressed lower transcripts of stress-inducible genes, such as RD29A, COR47 and ABF2, and photosynthesis-related genes proton gradient regulation 5 (PGR5) and PGR5-likephotosynthetic phenotype (PGRL1), but higher levels of nuclear-encoded genes alternative oxidase 1a (AOX1a) and oxidative signal-inducible 1 (OXI1). Prolonged ABA treatment increased the expression of the cox2 gene in complex IV and nad genes in complex I to a higher level than no ABA treatment in the wild type, but only to a moderate level in abo5, probably because abo5 already expressed high levels of mitochondrial-encoded cox2 and nad genes under no ABA treatment. More H(2) O(2) accumulated in the root tips of abo5 than in the wild type, and H(2) O(2) accumulation was further enhanced by ABA treatment. However, these growth phenotypes and gene-expression defects were attenuated by growing abo5 plants under short-day conditions (12-h light/12-h dark photoperiod). Our results indicate that ABO5 is important in the plant response to ABA.
Collapse
Affiliation(s)
- Yue Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
| | | | | | | | | | | |
Collapse
|
169
|
Abstract
Most differentiation events in higher plants occur continuously in the postembryonic adult phase of the life cycle. Embryogenesis in plants, therefore, is concerned primarily with establishing the basic shoot-root body pattern of the plant and accumulating food reserves that will be used by the germinating seedling after a period of embryonic dormancy within the seed. Recent genetics studies in Arabidopsis have identified genes that provide new insight into how embryos form during plant development. These studies, and others using molecular approaches, are beginning to reveal the underlying processes that control plant embryogenesis.
Collapse
|
170
|
Klingler JP, Batelli G, Zhu JK. ABA receptors: the START of a new paradigm in phytohormone signalling. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:3199-210. [PMID: 20522527 PMCID: PMC3107536 DOI: 10.1093/jxb/erq151] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The phytohormone abscisic acid (ABA) plays a central role in plant development and in plant adaptation to both biotic and abiotic stressors. In recent years, knowledge of ABA metabolism and signal transduction has advanced rapidly to provide detailed glimpses of the hormone's activities at the molecular level. Despite this progress, many gaps in understanding have remained, particularly at the early stages of ABA perception by the plant cell. The search for an ABA receptor protein has produced multiple candidates, including GCR2, GTG1, and GTG2, and CHLH. In addition to these candidates, in 2009 several research groups converged on a novel family of Arabidopsis proteins that bind ABA, and thereby interact directly with a class of protein phosphatases that are well known as critical players in ABA signal transduction. The PYR/PYL/RCAR receptor family is homologous to the Bet v 1-fold and START domain proteins. It consists of 14 members, nearly all of which appear capable of participating in an ABA receptor-signal complex that responds to the hormone by activating the transcription of ABA-responsive genes. Evidence is provided here that PYR/PYL/RCAR receptors can also drive the phosphorylation of the slow anion channel SLAC1 to provide a fast and timely response to the ABA signal. Crystallographic studies have vividly shown the mechanics of ABA binding to PYR/PYL/RCAR receptors, presenting a model that bears some resemblance to the binding of gibberellins to GID1 receptors. Since this ABA receptor family is highly conserved in crop species, its discovery is likely to usher a new wave of progress in the elucidation and manipulation of plant stress responses in agricultural settings.
Collapse
Affiliation(s)
- John P. Klingler
- Plant Stress Genomics Research Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Department of Botany and Plant Sciences, 2150 Batchelor Hall, University of California at Riverside, Riverside, California 92521, USA
| | - Giorgia Batelli
- Plant Stress Genomics Research Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Department of Botany and Plant Sciences, 2150 Batchelor Hall, University of California at Riverside, Riverside, California 92521, USA
| | - Jian-Kang Zhu
- Plant Stress Genomics Research Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Department of Botany and Plant Sciences, 2150 Batchelor Hall, University of California at Riverside, Riverside, California 92521, USA
- To whom correspondence should be addressed: E-mail:
| |
Collapse
|
171
|
Gambetta GA, Matthews MA, Shaghasi TH, McElrone AJ, Castellarin SD. Sugar and abscisic acid signaling orthologs are activated at the onset of ripening in grape. PLANTA 2010; 232:219-34. [PMID: 20407788 PMCID: PMC2872022 DOI: 10.1007/s00425-010-1165-2] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 03/30/2010] [Indexed: 05/18/2023]
Abstract
The onset of ripening involves changes in sugar metabolism, softening, and color development. Most understanding of this process arises from work in climacteric fruits where the control of ripening is predominately by ethylene. However, many fruits such as grape are nonclimacteric, where the onset of ripening results from the integration of multiple hormone signals including sugars and abscisic acid (ABA). In this study, we identified ten orthologous gene families in Vitis vinifera containing components of sugar and ABA-signaling pathways elucidated in model systems, including PP2C protein phosphatases, and WRKY and homeobox transcription factors. Gene expression was characterized in control- and deficit-irrigated, field-grown Cabernet Sauvignon. Sixty-seven orthologous genes were identified, and 38 of these were expressed in berries. Of the genes expressed in berries, 68% were differentially expressed across development and/or in response to water deficit. Orthologs of several families were induced at the onset of ripening, and induced earlier and to higher levels in response to water deficit; patterns of expression that correlate with sugar and ABA accumulation during ripening. Similar to field-grown berries, ripening phenomena were induced in immature berries when cultured with sucrose and ABA, as evidenced by changes in color, softening, and gene expression. Finally, exogenous sucrose and ABA regulated key orthologs in culture, similar to their regulation in the field. This study identifies novel candidates in the control of nonclimacteric fruit ripening and demonstrates that grape orthologs of key sugar and ABA-signaling components are regulated by sugar and ABA in fleshy fruit.
Collapse
Affiliation(s)
- Gregory A Gambetta
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA.
| | | | | | | | | |
Collapse
|
172
|
Lee JH, Yoon HJ, Terzaghi W, Martinez C, Dai M, Li J, Byun MO, Deng XW. DWA1 and DWA2, two Arabidopsis DWD protein components of CUL4-based E3 ligases, act together as negative regulators in ABA signal transduction. THE PLANT CELL 2010; 22:1716-32. [PMID: 20525848 PMCID: PMC2910972 DOI: 10.1105/tpc.109.073783] [Citation(s) in RCA: 198] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 05/05/2010] [Accepted: 05/17/2010] [Indexed: 05/19/2023]
Abstract
To elucidate potential roles of CUL4-DDB1-DWD (for Cullin 4-Damaged DNA Binding1-DDB1 binding WD40) E3 ligases in abscisic acid (ABA) signaling, we examined ABA sensitivities of T-DNA mutants of a number of Arabidopsis thaliana DWD genes, which encode substrate receptors for CUL4 E3 ligases. Mutants in two DWD genes, DWA1 and DWA2 (DWD hypersensitive to ABA1 and 2), had ABA-hypersensitive phenotypes. Both proteins interacted with DDB1 in yeast two-hybrid assays and associated with DDB1 and CUL4 in vivo, implying they could form CUL4-based complexes. Several ABA-responsive genes were hyperinduced in both mutants, and the ABA-responsive transcription factors ABA INSENSITIVE 5 (ABI5) and MYC2 accumulated to high levels in the mutants after ABA treatment. Moreover, ABI5 interacted with DWA1 and DWA2 in vivo. Cell-free degradation assays showed ABI5 was degraded more slowly in dwa1 and dwa2 than in wild-type cell extracts. Therefore, DWA1 and/or DWA2 may be the substrate receptors for a CUL4 E3 ligase that targets ABI5 for degradation. Our data indicate that DWA1 and DWA2 can directly interact with each other, and their double mutants exhibited enhanced ABA and NaCl hypersensitivities, implying they can act together. This report thus describes a previously unknown heterodimeric cooperation between two independent substrate receptors for CUL4-based E3 ligases.
Collapse
Affiliation(s)
- Jae-Hoon Lee
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
| | - Hye-Jin Yoon
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
- Department of Molecular Physiology and Biochemistry, National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon 441-707, Korea
| | - William Terzaghi
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
- Department of Biology, Wilkes University, Wilkes-Barre, Pennsylvania 18766
| | - Cristina Martinez
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
| | - Mingqiu Dai
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
| | - Jigang Li
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
| | - Myung-Ok Byun
- Department of Molecular Physiology and Biochemistry, National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon 441-707, Korea
| | - Xing Wang Deng
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
| |
Collapse
|
173
|
Zheng Z, Xu X, Crosley RA, Greenwalt SA, Sun Y, Blakeslee B, Wang L, Ni W, Sopko MS, Yao C, Yau K, Burton S, Zhuang M, McCaskill DG, Gachotte D, Thompson M, Greene TW. The protein kinase SnRK2.6 mediates the regulation of sucrose metabolism and plant growth in Arabidopsis. PLANT PHYSIOLOGY 2010; 153:99-113. [PMID: 20200070 PMCID: PMC2862418 DOI: 10.1104/pp.109.150789] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 03/01/2010] [Indexed: 05/18/2023]
Abstract
In higher plants, three subfamilies of sucrose nonfermenting-1 (Snf1)-related protein kinases have evolved. While the Snf1-related protein kinase 1 (SnRK1) subfamily has been shown to share pivotal roles with the orthologous yeast Snf1 and mammalian AMP-activated protein kinase in modulating energy and metabolic homeostasis, the functional significance of the two plant-specific subfamilies SnRK2 and SnRK3 in these critical processes is poorly understood. We show here that SnRK2.6, previously identified as crucial in the control of stomatal aperture by abscisic acid (ABA), has a broad expression pattern and participates in the regulation of plant primary metabolism. Inactivation of this gene reduced oil synthesis in Arabidopsis (Arabidopsis thaliana) seeds, whereas its overexpression increased Suc synthesis and fatty acid desaturation in the leaves. Notably, the metabolic alterations in the SnRK2.6 overexpressors were accompanied by amelioration of those physiological processes that require high levels of carbon and energy input, such as plant growth and seed production. However, the mechanisms underlying these functionalities could not be solely attributed to the role of SnRK2.6 as a positive regulator of ABA signaling, although we demonstrate that this kinase confers ABA hypersensitivity during seedling growth. Collectively, our results suggest that SnRK2.6 mediates hormonal and metabolic regulation of plant growth and development and that, besides the SnRK1 kinases, SnRK2.6 is also implicated in the regulation of metabolic homeostasis in plants.
Collapse
Affiliation(s)
- Zhifu Zheng
- Dow AgroSciences LLC, Indianapolis, Indiana 46268, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
174
|
Guard cell anion channel SLAC1 is regulated by CDPK protein kinases with distinct Ca2+ affinities. Proc Natl Acad Sci U S A 2010; 107:8023-8. [PMID: 20385816 DOI: 10.1073/pnas.0912030107] [Citation(s) in RCA: 411] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In response to drought stress, the phytohormone abscisic acid (ABA) induces stomatal closure. Thereby the stress hormone activates guard cell anion channels in a calcium-dependent, as well as -independent, manner. Open stomata 1 protein kinase (OST1) and ABI1 protein phosphatase (ABA insensitive 1) represent key components of calcium-independent ABA signaling. Recently, the guard cell anion channel SLAC1 was identified. When expressed heterologously SLAC1 remained electrically silent. Upon coexpression with Ca(2+)-independent OST1, however, SLAC1 anion channels appear activated in an ABI1-dependent manner. Mutants lacking distinct calcium-dependent protein kinases (CPKs) appeared impaired in ABA stimulation of guard cell ion channels, too. To study SLAC1 activation via the calcium-dependent ABA pathway, we studied the SLAC1 response to CPKs in the Xenopus laevis oocyte system. Split YFP-based protein-protein interaction assays, using SLAC1 as the bait, identified guard cell expressed CPK21 and 23 as major interacting partners. Upon coexpression of SLAC1 with CPK21 and 23, anion currents document SLAC1 stimulation by these guard cell protein kinases. Ca(2+)-sensitive activation of SLAC1, however, could be assigned to the CPK21 pathway only because CPK23 turned out to be rather Ca(2+)-insensitive. In line with activation by OST1, CPK activation of the guard cell anion channel was suppressed by ABI1. Thus the CPK and OST1 branch of ABA signal transduction in guard cells seem to converge on the level of SLAC1 under the control of the ABI1/ABA-receptor complex.
Collapse
|
175
|
Wu S, Scheible WR, Schindelasch D, Van Den Daele H, De Veylder L, Baskin TI. A conditional mutation in Arabidopsis thaliana separase induces chromosome non-disjunction, aberrant morphogenesis and cyclin B1;1 stability. Development 2010; 137:953-61. [PMID: 20150278 DOI: 10.1242/dev.041939] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The caspase family protease, separase, is required at anaphase onset to cleave the cohesin complex, which joins sister chromatids. However, among eukaryotes, separases have acquired novel functions. Here, we show that Arabidopsis thaliana radially swollen 4 (rsw4), a temperature-sensitive mutant isolated previously on the basis of root swelling, harbors a mutation in At4g22970, the A. thaliana separase. Loss of separase function in rsw4 at the restrictive temperature is indicated by the widespread failure of replicated chromosomes to disjoin. Surprisingly, rsw4 has neither pronounced cell cycle arrest nor anomalous spindle formation, which occur in other eukaryotes upon loss of separase activity. However, rsw4 roots have disorganized cortical microtubules and accumulate the mitosis-specific cyclin, cyclin B1;1, excessive levels of which have been associated with altered microtubules and morphology. Cyclin B1;1 also accumulates in certain backgrounds in response to DNA damage, but we find no evidence for aberrant responses to DNA damage in rsw4. Our characterization of rsw4 leads us to hypothesize that plant separase, in addition to cleaving cohesin, regulates cyclin B1;1, with profound ramifications for morphogenesis.
Collapse
Affiliation(s)
- Shuang Wu
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | | | | | | | | | | |
Collapse
|
176
|
Zhang H, Shen Z, Wang G, Dai X, Huang Q, Zheng K. Sensitivity to abscisic acid modulates positive interactions between Arabidopsis thaliana individuals. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2010; 52:340-346. [PMID: 20377695 DOI: 10.1111/j.1744-7909.2010.00909.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The ability of abscisic acid (ABA) to modulate positive interactions between Arabidopsis thaliana individuals under salinity stress was investigated using abi1-1 (insensitive to ABA), era1-2 (hypersensitive to ABA) mutant and wild type plants. The results showed that sensitivity to ABA affects relative interaction intensity (RII) between Arabidopsis thaliana individuals. The neighbor removal experiments also confirmed the role of phenotypic responses in linking plant-plant interactions and sensitivity to ABA. For abi1-1 mutants, the absolute value differences between neighbor removal and control of stem length, root length, leaf area, leaf thickness, flower density, above biomass/belowground biomass (A/U), photosynthetic rate, stomatal conductance, leaf water content and water-use efficiency were smaller than those of the wild type, while for era1-2 mutants, these absolute value differences were larger than those of the wild type. Thus, it is suggested that positive interactions between Arabidopsis thaliana individuals are at least partly modulated by different sensitivity to ABA through different physiological and phenotypic plasticity.
Collapse
Affiliation(s)
- Hao Zhang
- Center for Digital Agricultural Research, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | | | | | | | | | | |
Collapse
|
177
|
Assmann SM. Hope for Humpty Dumpty: systems biology of cellular signaling. PLANT PHYSIOLOGY 2010; 152:470-9. [PMID: 20032076 PMCID: PMC2815894 DOI: 10.1104/pp.109.151266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Affiliation(s)
- Sarah M Assmann
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
| |
Collapse
|
178
|
Saavedra X, Modrego A, Rodríguez D, González-García MP, Sanz L, Nicolás G, Lorenzo O. The nuclear interactor PYL8/RCAR3 of Fagus sylvatica FsPP2C1 is a positive regulator of abscisic acid signaling in seeds and stress. PLANT PHYSIOLOGY 2010; 152:133-50. [PMID: 19889877 PMCID: PMC2799352 DOI: 10.1104/pp.109.146381] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 10/30/2009] [Indexed: 05/21/2023]
Abstract
The functional protein phosphatase type 2C from beechnut (Fagus sylvatica; FsPP2C1) was a negative regulator of abscisic acid (ABA) signaling in seeds. In this report, to get deeper insight on FsPP2C1 function, we aim to identify PP2C-interacting partners. Two closely related members (PYL8/RCAR3 and PYL7/RCAR2) of the Arabidopsis (Arabidopsis thaliana) BetV I family were shown to bind FsPP2C1 in a yeast two-hybrid screening and in an ABA-independent manner. By transient expression of FsPP2C1 and PYL8/RCAR3 in epidermal onion (Allium cepa) cells and agroinfiltration in tobacco (Nicotiana benthamiana) as green fluorescent protein fusion proteins, we obtained evidence supporting the subcellular localization of both proteins mainly in the nucleus and in both the cytosol and the nucleus, respectively. The in planta interaction of both proteins in tobacco cells by bimolecular fluorescence complementation assays resulted in a specific nuclear colocalization of this interaction. Constitutive overexpression of PYL8/RCAR3 confers ABA hypersensitivity in Arabidopsis seeds and, consequently, an enhanced degree of seed dormancy. Additionally, transgenic 35S:PYL8/RCAR3 plants are unable to germinate under low concentrations of mannitol, NaCl, or paclobutrazol, which are not inhibiting conditions to the wild type. In vegetative tissues, Arabidopsis PYL8/RCAR3 transgenic plants show ABA-resistant drought response and a strong inhibition of early root growth. These phenotypes are strengthened at the molecular level with the enhanced induction of several ABA response genes. Both seed and vegetative phenotypes of Arabidopsis 35S:PYL8/RCAR3 plants are opposite those of 35S:FsPP2C1 plants. Finally, double transgenic plants confirm the role of PYL8/RCAR3 by antagonizing FsPP2C1 function and demonstrating that PYL8/RCAR3 positively regulates ABA signaling during germination and abiotic stress responses.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Oscar Lorenzo
- Departamento de Fisiología Vegetal, Centro Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, 37185 Salamanca, Spain
| |
Collapse
|
179
|
Nishimura N, Sarkeshik A, Nito K, Park SY, Wang A, Carvalho PC, Lee S, Caddell DF, Cutler SR, Chory J, Yates JR, Schroeder JI. PYR/PYL/RCAR family members are major in-vivo ABI1 protein phosphatase 2C-interacting proteins in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 61:290-9. [PMID: 19874541 PMCID: PMC2807913 DOI: 10.1111/j.1365-313x.2009.04054.x] [Citation(s) in RCA: 342] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 10/02/2009] [Accepted: 10/08/2009] [Indexed: 05/18/2023]
Abstract
Abscisic acid (ABA) mediates resistance to abiotic stress and controls developmental processes in plants. The group-A PP2Cs, of which ABI1 is the prototypical member, are protein phosphatases that play critical roles as negative regulators very early in ABA signal transduction. Because redundancy is thought to limit the genetic dissection of early ABA signalling, to identify redundant and early ABA signalling proteins, we pursued a proteomics approach. We generated YFP-tagged ABI1 Arabidopsis expression lines and identified in vivo ABI1-interacting proteins by mass-spectrometric analyses of ABI1 complexes. Known ABA signalling components were isolated including SnRK2 protein kinases. We confirm previous studies in yeast and now show that ABI1 interacts with the ABA-signalling kinases OST1, SnRK2.2 and SnRK2.3 in plants. Interestingly, the most robust in planta ABI1-interacting proteins in all LC-MS/MS experiments were nine of the 14 PYR/PYL/RCAR proteins, which were recently reported as ABA-binding signal transduction proteins, providing evidence for in vivo PYR/PYL/RCAR interactions with ABI1 in Arabidopsis. ABI1-PYR1 interaction was stimulated within 5 min of ABA treatment in Arabidopsis. Interestingly, in contrast, PYR1 and SnRK2.3 co-immunoprecipitated equally well in the presence and absence of ABA. To investigate the biological relevance of the PYR/PYLs, we analysed pyr1/pyl1/pyl2/pyl4 quadruple mutant plants and found strong insensitivities in ABA-induced stomatal closure and ABA-inhibition of stomatal opening. These findings demonstrate that ABI1 can interact with several PYR/PYL/RCAR family members in Arabidopsis, that PYR1-ABI1 interaction is rapidly stimulated by ABA in Arabidopsis and indicate new SnRK2 kinase-PYR/PYL/RCAR interactions in an emerging model for PYR/PYL/RCAR-mediated ABA signalling.
Collapse
Affiliation(s)
- Noriyuki Nishimura
- Division of Biological Sciences, Cell and Developmental Biology Section and Center for Molecular Genetics, University of CaliforniaSan Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA
| | - Ali Sarkeshik
- Department of Chemical Physiology, The Scripps Research Institute10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Kazumasa Nito
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Sang-Youl Park
- Department of Botany and Plant Sciences, University of California–RiversideRiverside, CA 92521, USA
| | - Angela Wang
- Division of Biological Sciences, Cell and Developmental Biology Section and Center for Molecular Genetics, University of CaliforniaSan Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA
| | - Paulo C Carvalho
- Department of Chemical Physiology, The Scripps Research Institute10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Stephen Lee
- Division of Biological Sciences, Cell and Developmental Biology Section and Center for Molecular Genetics, University of CaliforniaSan Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA
| | - Daniel F Caddell
- Division of Biological Sciences, Cell and Developmental Biology Section and Center for Molecular Genetics, University of CaliforniaSan Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA
| | - Sean R Cutler
- Department of Botany and Plant Sciences, University of California–RiversideRiverside, CA 92521, USA
| | - Joanne Chory
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Julian I Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section and Center for Molecular Genetics, University of CaliforniaSan Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA
- *For correspondence (fax +1 858 534 7108; e-mail )
| |
Collapse
|
180
|
Geiger D, Scherzer S, Mumm P, Stange A, Marten I, Bauer H, Ache P, Matschi S, Liese A, Al-Rasheid KAS, Romeis T, Hedrich R. Activity of guard cell anion channel SLAC1 is controlled by drought-stress signaling kinase-phosphatase pair. Proc Natl Acad Sci U S A 2009; 106:21425-30. [PMID: 19955405 PMCID: PMC2795561 DOI: 10.1073/pnas.0912021106] [Citation(s) in RCA: 627] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Indexed: 11/18/2022] Open
Abstract
In response to drought stress the phytohormone ABA (abscisic acid) induces stomatal closure and, therein, activates guard cell anion channels in a calcium-dependent as well as-independent manner. Two key components of the ABA signaling pathway are the protein kinase OST1 (open stomata 1) and the protein phosphatase ABI1 (ABA insensitive 1). The recently identified guard cell anion channel SLAC1 appeared to be the key ion channel in this signaling pathway but remained electrically silent when expressed heterologously. Using split YFP assays, we identified OST1 as an interaction partner of SLAC1 and ABI1. Upon coexpression of SLAC1 with OST1 in Xenopus oocytes, SLAC1-related anion currents appeared similar to those observed in guard cells. Integration of ABI1 into the SLAC1/OST1 complex, however, prevented SLAC1 activation. Our studies demonstrate that SLAC1 represents the slow, deactivating, weak voltage-dependent anion channel of guard cells controlled by phosphorylation/dephosphorylation.
Collapse
Affiliation(s)
- Dietmar Geiger
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| | - Sönke Scherzer
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| | - Patrick Mumm
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| | - Annette Stange
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| | - Irene Marten
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| | - Hubert Bauer
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| | - Peter Ache
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| | - Susanne Matschi
- Department of Plant Biochemistry, Free University Berlin, Koenigin-Luise-Str. 12-16, D-14195 Berlin, Germany; and
| | - Anja Liese
- Department of Plant Biochemistry, Free University Berlin, Koenigin-Luise-Str. 12-16, D-14195 Berlin, Germany; and
| | - Khaled A. S. Al-Rasheid
- Zoology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Tina Romeis
- Department of Plant Biochemistry, Free University Berlin, Koenigin-Luise-Str. 12-16, D-14195 Berlin, Germany; and
| | - Rainer Hedrich
- University Wuerzburg, Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, D-97082 Wuerzburg, Germany
| |
Collapse
|
181
|
The abscisic acid receptor PYR1 in complex with abscisic acid. Nature 2009; 462:665-8. [DOI: 10.1038/nature08591] [Citation(s) in RCA: 392] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 10/20/2009] [Indexed: 11/08/2022]
|
182
|
Santiago J, Rodrigues A, Saez A, Rubio S, Antoni R, Dupeux F, Park SY, Márquez JA, Cutler SR, Rodriguez PL. Modulation of drought resistance by the abscisic acid receptor PYL5 through inhibition of clade A PP2Cs. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 60:575-88. [PMID: 19624469 DOI: 10.1111/j.1365-313x.2009.03981.x] [Citation(s) in RCA: 367] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Abscisic acid (ABA) is a key phytohormone involved in adaption to environmental stress and regulation of plant development. Clade A protein phosphatases type 2C (PP2Cs), such as HAB1, are key negative regulators of ABA signaling in Arabidopsis. To obtain further insight into regulation of HAB1 function by ABA, we have screened for HAB1-interacting partners using a yeast two-hybrid approach. Three proteins were identified, PYL5, PYL6 and PYL8, which belong to a 14-member subfamily of the Bet v1-like superfamily. HAB1-PYL5 interaction was confirmed using BiFC and co-immunoprecipitation assays. PYL5 over-expression led to a globally enhanced response to ABA, in contrast to the opposite phenotype reported for HAB1-over-expressing plants. F(2) plants that over-expressed both HAB1 and PYL5 showed an enhanced response to ABA, indicating that PYL5 antagonizes HAB1 function. PYL5 and other members of its protein family inhibited HAB1, ABI1 and ABI2 phosphatase activity in an ABA-dependent manner. Isothermal titration calorimetry revealed saturable binding of (+)ABA to PYL5, with K(d) values of 1.1 mum or 38 nm in the absence or presence of the PP2C catalytic core of HAB1, respectively. Our work indicates that PYL5 is a cytosolic and nuclear ABA receptor that activates ABA signaling through direct inhibition of clade A PP2Cs. Moreover, we show that enhanced resistance to drought can be obtained through PYL5-mediated inhibition of clade A PP2Cs.
Collapse
Affiliation(s)
- Julia Santiago
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas - UPV, ES-46022 Valencia, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
183
|
Structural basis of abscisic acid signalling. Nature 2009; 462:609-14. [PMID: 19855379 DOI: 10.1038/nature08583] [Citation(s) in RCA: 376] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Accepted: 10/13/2009] [Indexed: 11/08/2022]
|
184
|
Nishimura N, Hitomi K, Arvai AS, Rambo RP, Hitomi C, Cutler SR, Schroeder JI, Getzoff ED. Structural mechanism of abscisic acid binding and signaling by dimeric PYR1. Science 2009; 326:1373-9. [PMID: 19933100 DOI: 10.1126/science.1181829] [Citation(s) in RCA: 347] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The phytohormone abscisic acid (ABA) acts in seed dormancy, plant development, drought tolerance, and adaptive responses to environmental stresses. Structural mechanisms mediating ABA receptor recognition and signaling remain unknown but are essential for understanding and manipulating abiotic stress resistance. Here, we report structures of pyrabactin resistance 1 (PYR1), a prototypical PYR/PYR1-like (PYL)/regulatory component of ABA receptor (RCAR) protein that functions in early ABA signaling. The crystallographic structure reveals an alpha/beta helix-grip fold and homodimeric assembly, verified in vivo by coimmunoprecipitation. ABA binding within a large internal cavity switches structural motifs distinguishing ABA-free "open-lid" from ABA-bound "closed-lid" conformations. Small-angle x-ray scattering suggests that ABA signals by converting PYR1 to a more compact, symmetric closed-lid dimer. Site-directed PYR1 mutants designed to disrupt hormone binding lose ABA-triggered interactions with type 2C protein phosphatase partners in planta.
Collapse
Affiliation(s)
- Noriyuki Nishimura
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California at San Diego, La Jolla, CA 92093, USA
| | | | | | | | | | | | | | | |
Collapse
|
185
|
Vlad F, Rubio S, Rodrigues A, Sirichandra C, Belin C, Robert N, Leung J, Rodriguez PL, Laurière C, Merlot S. Protein phosphatases 2C regulate the activation of the Snf1-related kinase OST1 by abscisic acid in Arabidopsis. THE PLANT CELL 2009; 21:3170-84. [PMID: 19855047 PMCID: PMC2782292 DOI: 10.1105/tpc.109.069179] [Citation(s) in RCA: 385] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Revised: 09/12/2009] [Accepted: 09/29/2009] [Indexed: 05/18/2023]
Abstract
The plant hormone abscisic acid (ABA) orchestrates plant adaptive responses to a variety of stresses, including drought. This signaling pathway is regulated by reversible protein phosphorylation, and genetic evidence demonstrated that several related protein phosphatases 2C (PP2Cs) are negative regulators of this pathway in Arabidopsis thaliana. Here, we developed a protein phosphatase profiling strategy to define the substrate preferences of the HAB1 PP2C implicated in ABA signaling and used these data to screen for putative substrates. Interestingly, this analysis designated the activation loop of the ABA activated kinase OST1, related to Snf1 and AMPK kinases, as a putative HAB1 substrate. We experimentally demonstrated that HAB1 dephosphorylates and deactivates OST1 in vitro. Furthermore, HAB1 and the related PP2Cs ABI1 and ABI2 interact with OST1 in vivo, and mutations in the corresponding genes strongly affect OST1 activation by ABA. Our results provide evidence that PP2Cs are directly implicated in the ABA-dependent activation of OST1 and further suggest that the activation mechanism of AMPK/Snf1-related kinases through the inhibition of regulating PP2Cs is conserved from plants to human.
Collapse
Affiliation(s)
- Florina Vlad
- Centre National de la Recherche Scientifique, Institut des Sciences du Végétal, UPR 2355, 91198 Gif-sur-Yvette Cedex, France
| | - Silvia Rubio
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, ES-46022 Valencia, Spain
| | - Americo Rodrigues
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, ES-46022 Valencia, Spain
| | - Caroline Sirichandra
- Centre National de la Recherche Scientifique, Institut des Sciences du Végétal, UPR 2355, 91198 Gif-sur-Yvette Cedex, France
| | - Christophe Belin
- Centre National de la Recherche Scientifique, Institut des Sciences du Végétal, UPR 2355, 91198 Gif-sur-Yvette Cedex, France
| | - Nadia Robert
- Centre National de la Recherche Scientifique, Institut des Sciences du Végétal, UPR 2355, 91198 Gif-sur-Yvette Cedex, France
| | - Jeffrey Leung
- Centre National de la Recherche Scientifique, Institut des Sciences du Végétal, UPR 2355, 91198 Gif-sur-Yvette Cedex, France
| | - Pedro L. Rodriguez
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, ES-46022 Valencia, Spain
| | - Christiane Laurière
- Centre National de la Recherche Scientifique, Institut des Sciences du Végétal, UPR 2355, 91198 Gif-sur-Yvette Cedex, France
- Address correspondence to
| | - Sylvain Merlot
- Centre National de la Recherche Scientifique, Institut des Sciences du Végétal, UPR 2355, 91198 Gif-sur-Yvette Cedex, France
| |
Collapse
|
186
|
Type 2C protein phosphatases directly regulate abscisic acid-activated protein kinases in Arabidopsis. Proc Natl Acad Sci U S A 2009; 106:17588-93. [PMID: 19805022 DOI: 10.1073/pnas.0907095106] [Citation(s) in RCA: 700] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Abscisic acid (ABA) signaling is important for stress responses and developmental processes in plants. A subgroup of protein phosphatase 2C (group A PP2C) or SNF1-related protein kinase 2 (subclass III SnRK2) have been known as major negative or positive regulators of ABA signaling, respectively. Here, we demonstrate the physical and functional linkage between these two major signaling factors. Group A PP2Cs interacted physically with SnRK2s in various combinations, and efficiently inactivated ABA-activated SnRK2s via dephosphorylation of multiple Ser/Thr residues in the activation loop. This step was suppressed by the RCAR/PYR ABA receptors in response to ABA. However the abi1-1 mutated PP2C did not respond to the receptors and constitutively inactivated SnRK2. Our results demonstrate that group A PP2Cs act as 'gatekeepers' of subclass III SnRK2s, unraveling an important regulatory mechanism of ABA signaling.
Collapse
|
187
|
Sakata Y, Komatsu K, Taji T, Tanaka S. Role of PP2C-mediated ABA signaling in the moss Physcomitrella patens. PLANT SIGNALING & BEHAVIOR 2009; 4:887-9. [PMID: 19847119 PMCID: PMC2802809 DOI: 10.4161/psb.4.9.9464] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Accepted: 07/07/2009] [Indexed: 05/21/2023]
Abstract
Plant hormone abscisic acid (ABA) is found in a wide range of land plants, from mosses to angiosperms. However, our knowledge concerning the function of ABA is limited to some angiosperm plant species. We have shown that the basal land plant Physcomitrella patens and the model plant Arabidopsis thaliana share a conserved abscisic acid (ABA) signaling pathway mediated through ABI1-related type 2C protein phosphatases (PP2Cs). Ectopic expression of Arabidopsis abi1-1, a dominant allele of ABI1 that functions as a negative regulator of ABA signaling, or targeted disruption of Physcomitrella ABI1-related gene (PpABI1A) resulted in altered ABA sensitivity and abiotic stress tolerance of Physcomitrella, as demonstrated by osmostress and freezing stress. Moreover, transgenic Physcomitrella overexpressing abi1-1 showed altered morphogenesis. These transgenic plants had longer stem lengths compared to the wild type, and continuous growth of archegonia (female organ) with few sporophytes under non-stress conditions. Our results suggest that PP2C-mediated ABA signaling is involved in both the abiotic stress responses and developmental regulation of Physcomitrella.
Collapse
Affiliation(s)
- Yoichi Sakata
- Department of BioScience, Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagayaku, Tokyo, Japan.
| | | | | | | |
Collapse
|
188
|
Papdi C, Joseph MP, Salamó IP, Vidal S, Szabados L. Genetic technologies for the identification of plant genes controlling environmental stress responses. FUNCTIONAL PLANT BIOLOGY : FPB 2009; 36:696-720. [PMID: 32688681 DOI: 10.1071/fp09047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Accepted: 06/11/2009] [Indexed: 06/11/2023]
Abstract
Abiotic conditions such as light, temperature, water availability and soil parameters determine plant growth and development. The adaptation of plants to extreme environments or to sudden changes in their growth conditions is controlled by a well balanced, genetically determined signalling system, which is still far from being understood. The identification and characterisation of plant genes which control responses to environmental stresses is an essential step to elucidate the complex regulatory network, which determines stress tolerance. Here, we review the genetic approaches, which have been used with success to identify plant genes which control responses to different abiotic stress factors. We describe strategies and concepts for forward and reverse genetic screens, conventional and insertion mutagenesis, TILLING, gene tagging, promoter trapping, activation mutagenesis and cDNA library transfer. The utility of the various genetic approaches in plant stress research we review is illustrated by several published examples.
Collapse
Affiliation(s)
- Csaba Papdi
- Institute of Plant Biology, Biological Research Centre, 6726-Szeged, Temesvári krt. 62, Hungary
| | - Mary Prathiba Joseph
- Institute of Plant Biology, Biological Research Centre, 6726-Szeged, Temesvári krt. 62, Hungary
| | - Imma Pérez Salamó
- Institute of Plant Biology, Biological Research Centre, 6726-Szeged, Temesvári krt. 62, Hungary
| | - Sabina Vidal
- Facultad de Ciencias, Universidad de la República, Iguá 4225, CP 11400, Montevideo, Uruguay
| | - László Szabados
- Institute of Plant Biology, Biological Research Centre, 6726-Szeged, Temesvári krt. 62, Hungary
| |
Collapse
|
189
|
Jia F, Gampala SS, Mittal A, Luo Q, Rock CD. Cre-lox univector acceptor vectors for functional screening in protoplasts: analysis of Arabidopsis donor cDNAs encoding ABSCISIC ACID INSENSITIVE1-like protein phosphatases. PLANT MOLECULAR BIOLOGY 2009; 70:693-708. [PMID: 19499346 PMCID: PMC2755202 DOI: 10.1007/s11103-009-9502-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Accepted: 05/15/2009] [Indexed: 05/27/2023]
Abstract
The 14,200 available full length Arabidopsis thaliana cDNAs in the universal plasmid system (UPS) donor vector pUNI51 should be applied broadly and efficiently to leverage a "functional map-space" of homologous plant genes. We have engineered Cre-lox UPS host acceptor vectors (pCR701- 705) with N-terminal epitope tags in frame with the loxH site and downstream from the maize Ubiquitin promoter for use in transient protoplast expression assays and particle bombardment transformation of monocots. As an example of the utility of these vectors, we recombined them with several Arabidopsis cDNAs encoding Ser/Thr protein phosphatase type 2C (PP2Cs) known from genetic studies or predicted by hierarchical clustering meta-analysis to be involved in ABA and stress responses. Our functional results in Zea mays mesophyll protoplasts on ABA-inducible expression effects on the Late Embryogenesis Abundant promoter ProEm:GUS reporter were consistent with predictions and resulted in identification of novel activities of some PP2Cs. Deployment of these vectors can facilitate functional genomics and proteomics and identification of novel gene activities.
Collapse
Affiliation(s)
- Fan Jia
- Department of Biological Sciences, Texas Tech University. Lubbock TX, U. S. A. 79409-3131
| | | | - Amandeep Mittal
- Department of Biological Sciences, Texas Tech University. Lubbock TX, U. S. A. 79409-3131
| | - Qingjun Luo
- Department of Biological Sciences, Texas Tech University. Lubbock TX, U. S. A. 79409-3131
| | - Christopher D. Rock
- Department of Biological Sciences, Texas Tech University. Lubbock TX, U. S. A. 79409-3131
| |
Collapse
|
190
|
Jiang W, Yu D. Arabidopsis WRKY2 transcription factor mediates seed germination and postgermination arrest of development by abscisic acid. BMC PLANT BIOLOGY 2009; 9:96. [PMID: 19622176 PMCID: PMC2719644 DOI: 10.1186/1471-2229-9-96] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2009] [Accepted: 07/22/2009] [Indexed: 05/17/2023]
Abstract
BACKGROUND Plant WRKY DNA-binding transcription factors are key regulators in certain developmental programs. A number of studies have suggested that WRKY genes may mediate seed germination and postgermination growth. However, it is unclear whether WRKY genes mediate ABA-dependent seed germination and postgermination growth arrest. RESULTS To determine directly the role of Arabidopsis WRKY2 transcription factor during ABA-dependent seed germination and postgermination growth arrest, we isolated T-DNA insertion mutants. Two independent T-DNA insertion mutants for WRKY2 were hypersensitive to ABA responses only during seed germination and postgermination early growth. wrky2 mutants displayed delayed or decreased expression of ABI5 and ABI3, but increased or prolonged expression of Em1 and Em6. wrky2 mutants and wild type showed similar levels of expression for miR159 and its target genes MYB33 and MYB101. Analysis of WRKY2 expression level in ABA-insensitive and ABA-deficient mutants abi5-1, abi3-1, aba2-3 and aba3-1 further indicated that ABA-induced WRKY2 accumulation during germination and postgermination early growth requires ABI5, ABI3, ABA2 and ABA3. CONCLUSION ABA hypersensitivity of the wrky2 mutants during seed germination and postgermination early seedling establishment is attributable to elevated mRNA levels of ABI5, ABI3 and ABI5-induced Em1 and Em6 in the mutants. WRKY2-mediated ABA responses are independent of miR159 and its target genes MYB33 and MYB101. ABI5, ABI3, ABA2 and ABA3 are important regulators of the transcripts of WRKY2 by ABA treatment. Our results suggest that WRKY2 transcription factor mediates seed germination and postgermination developmental arrest by ABA.
Collapse
Affiliation(s)
- Wenbo Jiang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China
- Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Diqiu Yu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China
| |
Collapse
|
191
|
Guo XH, Deng KQ, Wang J, Yu DS, Zhao Q, Liu XM. Mutational analysis of Arabidopsis PP2CA2 involved in abscisic acid signal transduction. Mol Biol Rep 2009; 37:763-9. [PMID: 19579056 DOI: 10.1007/s11033-009-9601-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 06/24/2009] [Indexed: 11/25/2022]
Abstract
The homozygous T-DNA mutant of the PP2CA2 gene in Arabidopsis thaliana was identified at DNA and RNA levels. The semi-quantitative RT-PCR analysis showed expression of PP2CA2 was induced by NaCl and ABA. When grown in presence of increasing concentration of exogenous ABA the pp2ca2 mutant showed a significant loss of ABA sensitivity in terms of seed germination, efficiency of post-germination growth and root growth. In presence of all ABA and NaCl concentrations tested the germination percentage of wild-type seeds was lower than that of mutant ppca2 seeds. Furthermore, in the presence of exogenous ABA, the pp2ca2 seeds showed higher germination percentages than wild-type at different stages of development and the pp2ca2 seedlings showed a reduced inhibition of root growth compared with wild-type plants. The above results indicated that the pp2ca2 was an ABA-hyposensitive mutant.
Collapse
Affiliation(s)
- Xin-Hong Guo
- Institute of Life Science and Biotechnology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, 410082, Changsha, People's Republic of China.
| | | | | | | | | | | |
Collapse
|
192
|
Rubio S, Rodrigues A, Saez A, Dizon MB, Galle A, Kim TH, Santiago J, Flexas J, Schroeder JI, Rodriguez PL. Triple loss of function of protein phosphatases type 2C leads to partial constitutive response to endogenous abscisic acid. PLANT PHYSIOLOGY 2009; 150:1345-55. [PMID: 19458118 PMCID: PMC2705020 DOI: 10.1104/pp.109.137174] [Citation(s) in RCA: 222] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 05/15/2009] [Indexed: 05/18/2023]
Abstract
The phytohormone abscisic acid (ABA) is a key regulator of plant growth and development as well as plant responses to situations of decreased water availability. Protein phosphatases type 2C (PP2Cs) from group A, which includes the ABI1/HAB1 and PP2CA branches, are key negative regulators of ABA signaling. Specifically, HAB1, ABI1, ABI2, and PP2CA have been shown to affect both seed and vegetative responses to ABA. To further understand their contribution to ABA signaling and to unravel possible genetic interactions and functional redundancy among them, we have generated different combinations of double and triple mutants impaired in these PP2Cs. Interestingly, hab1-1pp2ca-1 and abi1-2pp2ca-1 double mutants showed reduced water loss and enhanced resistance to drought stress, which further supports the role of PP2CA in vegetative responses to ABA. Two triple hab1-1abi1-2abi2-2 and hab1-1abi1-2pp2ca-1 mutants were generated, which showed an extreme response to exogenous ABA, impaired growth, and partial constitutive response to endogenous ABA. Thus, transcriptomic analysis revealed a partial up-regulation/down-regulation of a subset of ABA-responsive genes in both triple mutants in the absence of exogenous ABA. Comparison of ABA responses in the different pp2c mutants showed that a progressive increase in ABA sensitivity could be obtained through combined inactivation of these PP2Cs. These results indicate that ABA response is finely tuned by the integrated action of these genes, which is required to prevent a constitutive response to endogenous ABA that might have a deleterious effect on growth and development in the absence of environmental stress.
Collapse
Affiliation(s)
- Silvia Rubio
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, ES-46022 Valencia, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
193
|
Xu S, Ding H, Su F, Zhang A, Jiang M. Involvement of protein phosphorylation in water stress-induced antioxidant defense in maize leaves. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2009; 51:654-662. [PMID: 19566644 DOI: 10.1111/j.1744-7909.2009.00844.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Using pharmacological and biochemical approaches, the role of protein phosphorylation and the interrelationship between water stress-enhanced kinase activity, antioxidant enzyme activity, hydrogen peroxide (H2O2) accumulation and endogenous abscisic acid in maize (Zea mays L.) leaves were investigated. Water-stress upregulated the activities of total protein phosphorylation and Ca2+-dependent protein kinase, and the upregulation was blocked in abscisic acid-deficient vp5 mutant. Furthermore, pretreatments with a nicotinamide adenine dinucleotide phosphate oxidase inhibitor and a scavenger of H2O2 significantly reduced the increased activities of total protein kinase and Ca2+-dependent protein kinase in maize leaves exposed to water stress. Pretreatments with different protein kinase inhibitors also reduced the water stress-induced H2O2 production and the water stress-enhanced activities of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase. The data suggest that protein phosphorylation and H2O2 generation are required for water stress-induced antioxidant defense in maize leaves and that crosstalk between protein phosphorylation and H2O2 generation may occur.
Collapse
Affiliation(s)
- Shucheng Xu
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | | | | | | | | |
Collapse
|
194
|
Nakashima K, Fujita Y, Kanamori N, Katagiri T, Umezawa T, Kidokoro S, Maruyama K, Yoshida T, Ishiyama K, Kobayashi M, Shinozaki K, Yamaguchi-Shinozaki K. Three Arabidopsis SnRK2 Protein Kinases, SRK2D/SnRK2.2, SRK2E/SnRK2.6/OST1 and SRK2I/SnRK2.3, Involved in ABA Signaling are Essential for the Control of Seed Development and Dormancy. ACTA ACUST UNITED AC 2009; 50:1345-63. [DOI: 10.1093/pcp/pcp083] [Citation(s) in RCA: 521] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
195
|
Komatsu K, Nishikawa Y, Ohtsuka T, Taji T, Quatrano RS, Tanaka S, Sakata Y. Functional analyses of the ABI1-related protein phosphatase type 2C reveal evolutionarily conserved regulation of abscisic acid signaling between Arabidopsis and the moss Physcomitrella patens. PLANT MOLECULAR BIOLOGY 2009; 70:327-40. [PMID: 19266168 DOI: 10.1007/s11103-009-9476-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 02/22/2009] [Indexed: 05/04/2023]
Abstract
We employed a comparative genomic approach to understand protein phosphatase 2C (PP2C)-mediated abscisic acid (ABA) signaling in the moss Physcomitrella patens. Ectopic expression of Arabidopsis (Arabidopsis thaliana) abi1-1, a dominant mutant allele of ABI1 encoding a PP2C involved in the negative regulation of ABA signaling, caused ABA insensitivity of P. patens both in gene expression of late embryogenesis abundant (LEA) genes and in ABA-induced protonemal growth inhibition. The transgenic abi1-1 plants showed decreased ABA-induced freezing tolerance, and decreased tolerance to osmotic stress. Analyses of the P. patens genome revealed that only two (PpABI1A and PpABI1B) PP2C genes were related to ABI1. In the ppabi1a null mutants, ABA-induced expression of LEA genes was elevated, and protonemal growth was inhibited with lower ABA concentration compared to the wild type. Moreover, ABA-induced freezing tolerance of the ppabi1a mutants was markedly enhanced. We provide the genetic evidence that PP2C-mediated ABA signaling is evolutionarily conserved between Arabidopsis and P. patens.
Collapse
Affiliation(s)
- Kenji Komatsu
- Department of Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
196
|
Hu X, Zhang H, Li G, Yang Y, Zheng Z, Song F. Ectopic expression of a rice protein phosphatase 2C gene OsBIPP2C2 in tobacco improves disease resistance. PLANT CELL REPORTS 2009; 28:985-95. [PMID: 19381642 DOI: 10.1007/s00299-009-0701-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Revised: 02/12/2009] [Accepted: 03/31/2009] [Indexed: 05/04/2023]
Abstract
Protein phosphatase 2Cs (PP2Cs) have been demonstrated to play critical roles in regulation of plant growth/development, abscisic acid signaling pathway and adaptation to environmental stresses. Here we report the cloning and molecular characterization of a novel rice protein phosphatase 2C gene, OsBIPP2C2 (Oryza sativa L. BTH-induced protein phosphatase 2C 2). OsBIPP2C2 has three alternatively spliced transcripts and the largest transcript OsBIPP2C2a encodes a 380 aa protein containing all 11 conserved catalytic subdomains of PP2Cs. Expression of OsBIPP2C2a was significantly induced by benzothiadiazole (BTH), one of defense-related signal molecules in plants. Expression of OsBIP2C2a was induced by infection with the blast fungus, Magnaporthe grisea, and the pathogen-induced expression of OsBIPP2C2a in BTH-treated rice seedlings was much earlier and stronger than those in water-treated seedlings. Overexpression of OsBIPP2C2a in transgenic tobacco plants resulted in increased disease resistance against tobacco mosaic virus and Phytophthora parasitica var. nicotianae. Importantly, the OsBIPP2C2a-overexpressing transgenic tobacco plants showed constitutive expression of defense-related genes. These results suggest that OsBIPP2C2a may play an important role in disease resistance through activation of defense response.
Collapse
Affiliation(s)
- Xuebo Hu
- State Key Laboratory of Rice Biology, Department of Plant Protection, Institute of Biotechnology, Zhejiang University-Huajiachi Campus, 310029, Hangzhou, Zhejiang, People's Republic of China
| | | | | | | | | | | |
Collapse
|
197
|
Arabidopsis mutant deficient in 3 abscisic acid-activated protein kinases reveals critical roles in growth, reproduction, and stress. Proc Natl Acad Sci U S A 2009; 106:8380-5. [PMID: 19420218 DOI: 10.1073/pnas.0903144106] [Citation(s) in RCA: 560] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Abscisic acid (ABA) is an important phytohormone regulating seed dormancy, germination, seedling growth, and plant transpiration. We report here an Arabidopsis triple mutant that is disrupted in 3 SNF1-related protein kinase subfamily 2 (SnRK2s) and nearly completely insensitive to ABA. These SnRK2s, SnRK2.2, SnRK2.3, and SnRK2.6 (also known as OST1), are activated by ABA and can phosphorylate the ABA-responsive element binding factor family of b-ZIP transcription factors, which are important for the activation of ABA-responsive genes. Although stomatal regulation of snrk2.6 and seed germination and seedling growth of the snrk2.2/2.3 double mutant are insensitive to ABA, ABA responses are still present in these mutants, and the growth and reproduction of these mutants are not very different from those of the WT. In contrast, the snrk2.2/2.3/2.6 triple mutant grows poorly and produces few seeds. The triple mutant plants lose water extremely fast when ambient humidity is not high. Even on 50 muM ABA, the triple mutant can germinate and grow, whereas the most insensitive known mutants cannot develop on 10 muM ABA. In-gel kinase assays showed that all ABA-activated protein kinase activities are eliminated in the triple mutant. Also, the expression of ABA-induced genes examined is completely blocked in the triple mutant. These results demonstrate that the protein kinases SnRK2.2, SnRK2.3, and SnRK2.6 have redundant functions, and suggest that ABA signaling is critical for plant growth and reproduction.
Collapse
|
198
|
Sirichandra C, Wasilewska A, Vlad F, Valon C, Leung J. The guard cell as a single-cell model towards understanding drought tolerance and abscisic acid action. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:1439-63. [PMID: 19181866 DOI: 10.1093/jxb/ern340] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Stomatal guard cells are functionally specialized epidermal cells usually arranged in pairs surrounding a pore. Changes in ion fluxes, and more specifically osmolytes, within the guard cells drive opening/closing of the pore, allowing gas exchange while limiting water loss through evapo-transpiration. Adjustments of the pore aperture to optimize these conflicting needs are thus centrally important for land plants to survive, especially with the rise in CO(2) associated with global warming and increasing water scarcity this century. The basic biophysical events in modulating membrane transport have been gradually delineated over two decades. Genetics and molecular approaches in recent years have complemented and extended these earlier studies to identify major regulatory nodes. In Arabidopsis, the reference for guard cell genetics, stomatal opening driven by K(+) entry is mainly through KAT1 and KAT2, two voltage-gated K(+) inward-rectifying channels that are activated on hyperpolarization of the plasma membrane principally by the OST2 H(+)-ATPase (proton pump coupled to ATP hydrolysis). By contrast, stomatal closing is caused by K(+) efflux mainly through GORK, the outward-rectifying channel activated by membrane depolarization. The depolarization is most likely initiated by SLAC1, an anion channel distantly related to the dicarboxylate/malic acid transport protein found in fungi and bacteria. Beyond this established framework, there is also burgeoning evidence for the involvement of additional transporters, such as homologues to the multi-drug resistance proteins (or ABC transporters) as intimated by several pharmacological and reverse genetics studies. General inhibitors of protein kinases and protein phosphatases have been shown to profoundly affect guard cell membrane transport properties. Indeed, the first regulatory enzymes underpinning these transport processes revealed genetically were several protein phosphatases of the 2C class and the OST1 kinase, a member of the SnRK2 family. Taken together, these results are providing the first glimpses of an emerging signalling complex critical for modulating the stomatal aperture in response to environmental stimuli.
Collapse
Affiliation(s)
- Caroline Sirichandra
- Institut des Sciences du Végetal, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France
| | | | | | | | | |
Collapse
|
199
|
Abstract
Seed dormancy allows seeds to overcome periods that are unfavourable for seedling established and is therefore important for plant ecology and agriculture. Several processes are known to be involved in the induction of dormancy and in the switch from the dormant to the germinating state. The role of plant hormones, the different tissues and genes involved, including newly identified genes in dormancy and germination are described in this chapter, as well as the use transcriptome, proteome and metabolome analyses to study these mechanistically not well understood processes.
Collapse
Affiliation(s)
- Leónie Bentsink
- Department of Molecular Plant Physiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Maarten Koornneef
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
- Laboratory of Genetics, Wageningen University, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands
| |
Collapse
|
200
|
Zhang Y, Xu W, Li Z, Deng XW, Wu W, Xue Y. F-box protein DOR functions as a novel inhibitory factor for abscisic acid-induced stomatal closure under drought stress in Arabidopsis,. PLANT PHYSIOLOGY 2008; 4:470-1. [PMID: 18835996 PMCID: PMC2593669 DOI: 10.1104/pp.108.126912] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 09/29/2008] [Indexed: 05/18/2023]
Abstract
Guard cells, which form stoma in leaf epidermis, sense and integrate environmental signals to modulate stomatal aperture in response to diverse conditions. Under drought stress, plants synthesize abscisic acid (ABA), which in turn induces a rapid closing of stoma, to prevent water loss by transpiration. However, many aspects of the molecular mechanism for ABA-mediated stomatal closure are still not understood. Here, we report a novel negative regulator of guard cell ABA signaling, DOR, in Arabidopsis (Arabidopsis thaliana). The DOR gene encodes a putative F-box protein, a member of the S-locus F-box-like family related to AhSLF-S(2) and specifically interacting with ASK14 and CUL1. A null mutation in DOR resulted in a hypersensitive ABA response of stomatal closing and a substantial increase of drought tolerance; in contrast, the transgenic plants overexpressing DOR were more susceptible to the drought stress. DOR is strongly expressed in guard cells and suppressed by ABA treatment, suggesting a negative feedback loop of DOR in ABA responses. Double-mutant analyses of dor with ABA-insensitive mutant abi1-1 showed that abi1-1 is epistatic to dor, but no apparent change of phospholipase Dalpha1 was detected between the wild type and dor. Affymetrix GeneChip analysis showed that DOR likely regulates ABA biosynthesis under drought stress. Taken together, our results demonstrate that DOR acts independent of phospholipase Dalpha1 in an ABA signaling pathway to inhibit the ABA-induced stomatal closure under drought stress.
Collapse
Affiliation(s)
- Yu'e Zhang
- Department of Plant Sciences, College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100094, China
| | | | | | | | | | | |
Collapse
|