499 / 2019-02-28 17:35:33

Histone Acetyltransferase GCN5 Contributes to Wax Accumulation in Plants

GCN5,Histone acetylation,Arabidopsis thaliana,Wheat,Wax

Epigenetic Regulation > Epigenetic Regulation

Histone acetylation regulates the expression of genes involved in diverse biological processes. Primarily studies from Arabidopsis demonstrate that mutations of GCN5 impaired the accumulation of stem cuticular wax. Three target genes of GCN5, CER3, CER26, and CER1-L1, were identified by RNA-seq and ChIP assays. H3K9/14 acetylation levels at the promoter regions of CER3, CER26, and CER1-L1 were consistently and significantly decreased in the gcn5-2 mutant as compared to the wild-type. Notably, overexpression of CER3 in the gcn5-2 mutant rescued the defect in stem cuticular wax biosynthesis. Collectively, these data demonstrate that GCN5 is involved in stem cuticular wax accumulation by modulating CER3 expression via H3K9/14 acetylation in Arabidopsis. Because the particularity of wax components and biosynthesis process in wheat, we made the mutants of wheat GCN5 by gene editing to investigate how GCN5 impacts the wax content in wheat. Using the bluish-white identification and scanning electron microscope assays, it is revealed that mutation of TaGCN5 severely impaired epicuticular wax accumulation of leaves at the filling stage. Gene Ontology analysis exhibited that a group of lipid metabolism genes were enriched in the down-regulated genes in the tagcn5 mutants vs. wild-type by RNA-Seq. By combining ChIP-Seq assays, we will investigate the direct targets of TaGCN5 that are known to implicated to function in the epicuticular wax biosynthesis and/or transport.