Histone Acetyltransferases (HATs) in Chinese Cabbage: Insights from Histone H3 Acetylation and Expression Profiling of HATs in Response to Abiotic Stresses

Histone acetyltransferase (HAT) is known as an epigenetic enzyme that acetylates specific lysine residues on the histone tail to promote chromatin dynamics and gene expression. In higher plants, HATs have been recognized as playing a fundamental role in plant development, growth, and the response to diverse environmental stresses. In this study, using comprehensive bioinformatic analyses, we identified 15 HATs in genome of chinese cabbage [Brassica rapa (BraHATs)], which are divided into four families. In addition, evolution analysis suggested that the BraHAT genes were duplicated mainly via a segmental duplication event originating 3.05-18.39 million years ago. To determine the effects of abiotic stresses, such as salt, wounding, and drought, on histone H3 acetylation in chinese cabbage, histone H3 acetylation was analyzed via immunoblot analysis, suggesting that the acetylation level of histone H3 increased in response to wounding and salt stresses. Furthermore, the analysis of BraHAT expression patterns using quantitative real-time polymerase chain reaction (qRT-PCR) suggested that the increased acetylation of histone H3 was related to BraHAT transcripts and/or the functional interplay between HAT and histone deacetylase (HDAC) activities. Taken together, our comparative genomic analysis of HAT genes in this important vegetable crop will provide a solid foundation to further our understanding of epigenetically regulated processes in response to environmental stresses.