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ABSTRACT: As a sessile organism, plant encounters various environmental stimuli including abiotic stresses during their lifecycle. To survive under adverse conditions, plants have evolved intricate mechanisms to perceive the external signals and respond accordingly. Responses to various stresses largely depend on the plant capacity to modulate the transcriptome rapidly and specifically. A number of studies have shown that the molecular mechanisms driving the responses of plants to environmental stresses often depend on nucleosome histone post-translational modifications including histone acetylation, methylation, ubiquitination and phosphorylation. The combined effects of these modifications play an essential role in the regulation of stress responsive gene expression. In this review, we highlight our current understanding of the epigenetic mechanisms of histone modifications and their roles in plant abiotic stress response.
Journal of Integrative Plant Biology 05/2013; · 2.53 Impact Factor
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Xuncheng Liu,
Chia-Yang Chen,
Ko-Ching Wang,
Ming Luo,
Ready Tai,
Lianyu Yuan,
Minglei Zhao,
Songguang Yang,
Gang Tian,
Yuhai Cui,
Hsu-Liang Hsieh,
Keqiang Wu
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ABSTRACT: PHYTOCHROME INTERACTING FACTOR3 (PIF3) is a key basic helix-loop-helix transcription factor of Arabidopsis thaliana that negatively regulates light responses, repressing chlorophyll biosynthesis, photosynthesis, and photomorphogenesis in the dark. However, the mechanism for the PIF3-mediated transcription regulation remains largely unknown. In this study, we found that the REDUCED POTASSIUM DEPENDENCY3/HISTONE DEACETYLASE1-type histone deacetylase HDA15 directly interacted with PIF3 in vivo and in vitro. Genome-wide transcriptome analysis revealed that HDA15 acts mainly as a transcriptional repressor and negatively regulates chlorophyll biosynthesis and photosynthesis gene expression in etiolated seedlings. HDA15 and PIF3 cotarget to the genes involved in chlorophyll biosynthesis and photosynthesis in the dark and repress gene expression by decreasing the acetylation levels and RNA Polymerase II-associated transcription. The binding of HDA15 to the target genes depends on the presence of PIF3. In addition, PIF3 and HDA15 are dissociated from the target genes upon exposure to red light. Taken together, our results indicate that PIF3 associates with HDA15 to repress chlorophyll biosynthetic and photosynthetic genes in etiolated seedlings.
The Plant Cell 04/2013; · 8.99 Impact Factor
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ABSTRACT: ASYMMETRIC LEAVES 1 (AS1) is a MYB-type transcription repressor that controls leaf development by regulating KNOX gene expression, but the underlying molecular mechanism is still unclear. In this study, we demonstrated that AS1 can interact with the histone deacetylase HDA6 in vitro and in vivo. The KNOX genes were up-regulated and hyperacetylated in the hda6 mutant, axe1-5, indicating that HDA6 may regulate KNOX expression through histone deacetylation. Compared with the single mutants, the as1-1/axe1-5 and as2-1/axe1-5 double mutants displayed more severe serrated leaf and short petiole phenotypes. In addition, the frequencies of leaf lobes and leaflet-like structures were also increased in as1-1/axe1-5 and as2-1/axe1-5 double mutants, suggesting that HDA6 acts together with AS1 and AS2 in regulating leaf development. Chromatin immunoprecipitation assays revealed that HDA6 and AS1 bound directly to KNAT1, KNAT2, and KNATM chromatin. Taken together, these data indicate that HDA6 is a part of the AS1 repressor complex to regulate the KNOX expression in leaf development.
PLoS Genetics 12/2012; 8(12):e1003114. · 8.69 Impact Factor
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ABSTRACT: HD2 proteins were previously identified as plant specific histone deacetylases (HDACs). The molecular mechanism of the function of HD2 proteins is still unclear. Using Bimolecular fluorescence complementation assay, we demonstrated that Arabidopsis HD2 proteins, HD2A, HD2C and HD2D, can interact with RPD3-type HDACs, HDA6 and HDA19, suggesting that that these proteins may act in the same protein complex. Our study indicates that HD2 proteins may functionally associate with RPD3-type HDACs to regulate gene expression in plants.
Plant signaling & behavior 06/2012; 7(6):608-10.
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ABSTRACT: One of the most fundamental questions in the control of gene expression is how epigenetic patterns of DNA methylation and histone modifications are established. Our recent studies demonstrate that histone deacetylase HDA6 integrates DNA methylation and histone modifications in gene silencing by interacting with DNA methyltransferase MET1 and histone demethylase FLD, suggesting that regulatory crosstalk between histone modifications and DNA methylation could be mediated by the interaction of various epigenetic modification proteins.
Plant signaling & behavior 06/2012; 7(6):633-5.
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ABSTRACT: HD2 proteins are plant specific histone deacetylases. Four HD2 proteins, HD2A, HD2B, HD2C, and HD2D, have been identified in Arabidopsis. It was found that the expression of HD2A, HD2B, HD2C, and HD2D was repressed by ABA and NaCl. To investigate the function of HD2 proteins further, two HD2C T-DNA insertion lines of Arabidopsis, hd2c-1 and hd2c-3 were identified. Compared with wild-type plants, hd2c-1 and hd2c-3 plants displayed increased sensitivity to ABA and NaCl during germination and decreased tolerance to salt stress. These observations support a role of HD2C in the ABA and salt-stress response in Arabidopsis. Moreover, it was demonstrated that HD2C interacted physically with a RPD3-type histone deacetylase, HDA6, and bound to histone H3. The expression of ABA-responsive genes, ABI1 and ABI2, was increased in hda6, hd2c, and hda6/hd2c-1 double mutant plants, which was associated with increased histone H3K9K14 acetylation and decreased histone H3K9 dimethylation. Taken together, our results suggested that HD2C functionally associates with HDA6 and regulates gene expression through histone modifications.
Journal of Experimental Botany 02/2012; 63(8):3297-306. · 5.36 Impact Factor
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ABSTRACT: Author Summary
AS1 is a MYB-type transcription repressor that controls leaf patterning by repressing class-1 KNOX gene expression. The molecular mechanism by which AS1 represses KNOX gene expression is still unclear. In this study, we found that AS1 interacted with the histone deacetylase HDA6. Furthermore, HDA6 repressed KNOX gene expression by histone deacetylation. hda6 mutants displayed serrated leaf and short petiole phenotypes. Additionally, hda6/as1-1 double-mutant plants showed a more severe phenotype compared to the single mutants, indicating that HDA6 may act together with AS1 in controlling leaf development. Taken together, our data indicated that HDA6 is an important component of the AS1 repressor complex in regulating the KNOX gene expression.
PLoS Genetics 01/2012; 8(12):e1003114. · 8.69 Impact Factor
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ABSTRACT: The molecular mechanism of how the histone deacetylase HDA6 participates in maintaining transposable element (TE) silencing in Arabidopsis (Arabidopsis thaliana) is not yet defined. In this study, we show that a subset of TEs was transcriptionally reactivated and that TE reactivation was associated with elevated histone H3 and H4 acetylation as well as increased H3K4Me3 and H3K4Me2 in hda6 mutants. Decreased DNA methylation of the TEs was also detected in hda6 mutants, suggesting that HDA6 silences the TEs by regulating histone acetylation and methylation as well as the DNA methylation status of the TEs. Similarly, transcripts of some of these TEs were also increased in the methyltransferase1 (met1) mutant, with decreased DNA methylation. Furthermore, H4 acetylation, H3K4Me3, H3K4Me2, and H3K36Me2 were enriched at the coregulated TEs in the met1 and hda6 met1 mutants. Protein-protein interaction analysis indicated that HDA6 physically interacts with MET1 in vitro and in vivo, and further deletion analysis demonstrated that the carboxyl-terminal region of HDA6 and the bromo-adjacent homology domain of MET1 were responsible for the interaction. These results suggested that HDA6 and MET1 interact directly and act together to silence TEs by modulating DNA methylation, histone acetylation, and histone methylation status.
Plant physiology 01/2012; 158(1):119-29. · 6.53 Impact Factor
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ABSTRACT: Cadmium (Cd), a non-essential metal, is a kind of toxic heavy metal to life, which can accumulate in rice tissues including seeds, thus posing a risk to human health through food chain. To investigate the molecular mechanisms of rice response to Cd exposure, suppression subtractive hybridization and mirror orientation selection were used to compare gene expression profiles in seedling roots of Cd-exposed and control (unexposed) rice plants (Oryza sativa L., Nipponbare). Approximately 1700 positive clones, with insertions ranging from 250 to 1300 bp, were identified through reverse cDNA microarray analysis. Gene expression was further confirmed by real time RT-PCR. A number of differentially expressed genes were found in Cd-exposed rice roots, including 28 up-regulated genes and 19 down-regulated genes. They were found to be involved in diverse biological processes, such as metabolism, stress response, ion transport and binding, protein structure and synthesis, as well as signal transduction. Notably a number of known functional genes were identified encoding membrane proteins and stress-related proteins such as heat shock proteins, monosaccharide transporters, CBL-interacting serine/threonine-protein kinases and metal tolerance proteins. The cDNAs isolated in this study contribute to our understanding of genes and the biochemical pathways that may play a key role in the response of plants to metal exposure in the environment.
Plant Physiology and Biochemistry 08/2011; 50(1):79-86. · 2.84 Impact Factor
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ABSTRACT: Sensing environmental changes and initiating a gene expression response are important for plants as sessile autotrophs. The ability of epigenetic status to alter rapidly and reversibly could be a key component to the flexibility of plant responses to the environment. The involvement of epigenetic mechanisms in the response to environmental cues and to different types of abiotic stresses has been documented. Different environmental stresses lead to altered methylation status of DNA as well as modifications of nucleosomal histones. Understanding how epigenetic mechanisms are involved in plant response to environmental stress is highly desirable, not just for a better understanding of molecular mechanisms of plant stress response but also for possible application in the genetic manipulation of plants. In this review, we highlight our current understanding of the epigenetic mechanisms of chromatin modifications and remodeling, with emphasis on the roles of specific modification enzymes and remodeling factors in plant abiotic stress responses. This article is part of a Special Issue entitled: Plant gene regulation in response to abiotic stress.
Biochimica et Biophysica Acta 06/2011; 1819(2):129-36. · 4.66 Impact Factor
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ABSTRACT: High hydrostatic pressure (HHP) is an extreme thermal-physical stress affecting multiple cellular activities. Recently, we found that HHP treatment caused various physiological changes in rice. To investigate the molecular mechanisms of plant response to HHP, we constructed forward and reverse subtracted cDNA libraries of rice seeds treated with 75MPa hydrostatic pressure for 12h by suppression subtractive hybridization in combination with mirror orientation selection. Of 97 clones isolated through microarray dot-blot and sequenced, 45 were unique genes. Among these 45 unique cDNAs, 29 clones showed significant sequence similarity to known genes, 12 were homologous to genes with unknown function, and the remaining 4 clones did not match any known sequences. Most of the genes with known function were involved in metabolism, defense response, transcriptional regulation, transportation regulation, and signal transduction. To our knowledge, this is the first gene expression analysis of rice in response to HHP. The expression profiles of the genes identified in this study provide useful information regarding molecular processes, including alteration of metabolism and adaptation response caused by HHP.
Journal of plant physiology 12/2008; 165(18):1855-64. · 2.50 Impact Factor
