Maize Histone Deacetylasehda101Is Involved in Plant Development, Gene Transcription, and Sequence-Specific Modulation of Histone Modification of Genes and Repeats

Abstract

Enzymes catalyzing histone acetylation and deacetylation contribute to the modulation of chromatin structure, thus playing an important role in regulating gene and genome activity. We showed that downregulation and overexpression of the maize (Zea mays) Rpd3-type hda101 histone deacetylase gene induced morphological and developmental defects. Total levels of acetylated histones and histone acetylation of both repetitive and nonrepetitive sequences were affected in hda101 transgenic mutants. However, only transcript levels of genes but not repeats were altered. In particular, hda101 transgenic mutants showed differential expression of genes involved in vegetative-to-reproductive transition, such as liguleless2 and knotted-like genes and their repressor rough sheath2, which are required for meristem initiation and maintenance. Perturbation of hda101 expression also affected histone modifications other than acetylation, including histone H3 dimethylation at Lys-4 and Lys-9 and phosphorylation at Ser-10. Our results indicate that hda101 affects gene transcription and provide evidence of its involvement in setting the histone code, thus mediating developmental programs. Possible functional differences between maize hda101 and its Arabidopsis thaliana ortholog HDA19 are discussed.

Chromatin and DNA Modifications in theOpaque2-Mediated Regulation of Gene Transcription during Maize Endosperm Development

“…McrBC digests DNA that is methylated at two or more cytosines, thus reducing PCR amplification proportionally to the m C level in the sequence encompassed by the selected primers (Rossi et al, 2007). The results indicated that m C in the promoter of O2 targets and of the azs19.B-1-4 locus was higher in leaves compared with endosperms ( Figure 3).…”

“…This experiment provided evidence for possible changes in nucleosome occupancy during transcription activation and was also relevant to appropriately correct ChIP data obtained using antibodies against modified histones. Indeed, nucleosome density may not be homogeneous across the genome in different transcriptional states or in mutants affecting histone modifier activity (Ng et al, 2006;Rossi et al, 2007). This implies that nucleosome-rich and nucleosome-poor regions may appear as more and as less modified then they really are, respectively.…”

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

“…Several physiological outputs of histone deacetylation that are highly relevant for plant biotechnology can be titrated through HDC1 expression, without producing any of the morphological abnormalities observed for manipulation of HDACs in Arabidopsis, rice, and maize (Tian and Chen, 2001;Jang et al, 2003;Zhou et al, 2005;Rossi et al, 2007;Tanaka et al, 2008). Thus, HDC1 opens avenues to exploit epigenetic regulation for crop improvement without risking unwanted side effects caused by interference with fundamental roles of chromatin modifications in tissue differentiation.…”

Epigenetic Regulation of Abiotic Stress Tolerance in Plants

“…Knockout mutants and RNAi lines of stress-inducible histone deacetylase of Arabidopsisand maize showed increase in histone acetylation accompanied by changes in histone methylation pattern and derepression of silenced genes. 26,27 Thus, dynamic histone modification marks could be converted into DNA methylation marks, which are often more stable.…”