HISTONE DEACETYLASE6 Interacts with FLOWERING LOCUS D and Regulates Flowering in Arabidopsis      

Abstract

Histone acetylation and deacetylation play an important role in epigenetic controls of gene expression. HISTONE DEACETYLASE6 (HDA6) is a REDUCED POTASSIUM DEPENDENCY3-type histone deacetylase, and the Arabidopsis (Arabidopsis thaliana) hda6 mutant axe1-5 displayed a late-flowering phenotype. axe1-5/flc-3 double mutants flowered earlier than axe1-5 plants, indicating that the late-flowering phenotype of axe1-5 was FLOWERING LOCUS C (FLC) dependent. Bimolecular fluorescence complementation, in vitro pull-down, and coimmunoprecipitation assays revealed the protein-protein interaction between HDA6 and the histone demethylase FLD. It was found that the SWIRM domain in the amino-terminal region of FLD and the carboxyl-terminal region of HDA6 are responsible for the interaction between these two proteins. Increased levels of histone H3 acetylation and H3K4 trimethylation at FLC, MAF4, and MAF5 were found in both axe1-5 and fld-6 plants, suggesting functional interplay between histone deacetylase and demethylase in flowering control. These results support a scenario in which histone deacetylation and demethylation cross talk are mediated by physical association between HDA6 and FLD. Chromatin immunoprecipitation analysis indicated that HDA6 bound to the chromatin of several potential target genes, including FLC and MAF4. Genome-wide gene expression analysis revealed that, in addition to genes related to flowering, genes involved in gene silencing and stress response were also affected in hda6 mutants, revealing multiple functions of HDA6. Furthermore, a subset of transposons was up-regulated and displayed increased histone hyperacetylation, suggesting that HDA6 can also regulate transposons through deacetylating histone.

Histone Deacetylase Complex1 Expression Level Titrates Plant Growth and Abscisic Acid Sensitivity in Arabidopsis

“…The fact that hdc1 knockout inhibited both of these HDAC-mediated processes (Song et al, 2005;Yu et al, 2011) although they involve different repressors (ETHYLENE RESPONSE FACTOR7 and FLOWERING LOCUS D, respectively) and different transcriptional targets (ABAinducible genes and FLC, respectively) positions HDC1 action upstream of the respective signaling pathways. A third phenotype consisting in reduced vegetative growth was also found to be shared between hdc1-1 and hda6 (axe1-5) mutants (Figure 8; see Supplemental Figure 7 online), thus adding further evidence for a closely related function.…”

“…Within this context, deacetylation of Lys residues in histones 3 and 4, catalyzed by histone deacetylases (HDACs), establishes a repressive mark (Kouzarides, 2007;Roudier et al, 2009). In plants, histone deacetylation supports fundamental life functions, including maintenance of genome stability (Probst et al, 2004;To et al, 2011;Liu et al, 2012), determination of cell-type specificity (Xu et al, 2005;Hollender and Liu, 2008), and transition between developmental stages (Tanaka et al, 2008;Yu et al, 2011). Gene repression through histone deacetylation is also an important part of the hormonal signaling pathways that orchestrate plant responses to biotic or abiotic stress factors in the environment (Zhou et al, 2005;.…”

“…For example, HDA6 silences transposons and repetitive elements in a process that is at least partially coupled to DNA methylation (Probst et al, 2004;To et al, 2011;Liu et al, 2012). HDA6 and HDA19 redundantly silence embryonic genes after germination, and in mature plants, HDA6 induces flowering by repressing the flowering inhibitor FLOWERING LOCUS C (FLC; Tanaka et al, 2008;Yu et al, 2011). Furthermore, HDA6 and HDA19 are required for jasmonate/ethylene-mediated defense responses to pathogens (Zhou et al, 2005;Zhu et al, 2011) and for abscisic acid (ABA)-mediated responses to drought or salt .…”

PHYTOCHROME INTERACTING FACTOR3 Associates with the Histone Deacetylase HDA15 in Repression of Chlorophyll Biosynthesis and Photosynthesis in EtiolatedArabidopsisSeedlings

“…ChIP assays were performed as described (Gendrel et al, 2005;Yu et al, 2011;Liu et al, 2012). Chromatin was extracted from 2-d-old dark grown seedlings.…”

Abiotic Stress Responses in Plants: A Focus on the SRO Family

“…The histone deacetylase HDA6 is involved in ABA signalling and salt stress response and required for jasmonate-induced gene expression in addition to a role in flowering time control (LT. Chen et al, 2010;K. Wu et al, 2008;Yu et al, 2011). It is also necessary for freezing tolerance (To et al, 2011a).…”