Regulation of histone 3 acetylation for increasing ginsenoside production in adventitious root cultures of Panax ginseng

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 contrast, histone deacetylase (HDAC) removes the acetyl functional groups from the lysine residues of histone tails. This indicates that HATs and HDACs play a role as transcriptional activators or repressors involved in multiple biological processes. Despite the knowledge concerning HATs and HDACs, evolutionary and functional information regarding HATs and HDACs in Panax ginseng are still unknown. In this study, using comprehensive bioinformatic analyses, we identified 13 HATs (PgHATs) and 26 HDACs (PgHDACs) in the P. ginseng genome. The expression analysis using qRT-PCR revealed spatial variations in the expression of PgHATs and PgHDACs in different organs. Methyl jasmonate (MeJA), a vital plant hormone essential for plant defense responses and developmental processes, is an effective elicitor of ginsenoside biosynthesis in cultured cells and adventitious roots of P. ginseng [1]. To investigate the role of histone 3 (H3) acetylation on the MeJA-induced ginsenoside biosynthesis, ginseng adventitious roots were co-treated with MeJA and histone deacetylase inhibitors sodium butyrate and vorinostat. The expression of ginsenoside biosynthesis-related genes and the production of ginsenosides were significantly increased by MeJA and inhibitor co-treatment compared with the MeJA-treated samples. In addition, the analysis of histone H3 acetylation using immunoblotting suggested that histone deacetylase inhibitors enhanced MeJA-induced acetylation of histone H3 lysine 14, 18 and 27, indicating that histone H3 acetylation is required for stimuli-induced expression of ginsenoside biosynthesis-related genes.

• References

• 1 Kim YS, Hahn EJ, Murthy HN, Paek KY. Adventitious root growth and ginsenoside accumulation in Panax ginseng cultures as affected by methyl jasmonate. Biotechnol Lett 2004; 26: 1619-1622