HDT701, a Histone H4 Deacetylase, Negatively Regulates Plant Innate Immunity by Modulating Histone H4 Acetylation of Defense-Related Genes in Rice  

Abstract

Histone acetylation and deacetylation play an important role in the modification of chromatin structure and regulation of gene expression in eukaryotes. Chromatin acetylation status is modulated antagonistically by histone acetyltransferases and histone deacetylases (HDACs). In this study, we characterized the function of histone deacetylase701 (HDT701), a member of the plant-specific HD2 subfamily of HDACs, in rice (Oryza sativa) innate immunity. Transcription of HDT701 is increased in the compatible reaction and decreased in the incompatible reaction after infection by the fungal pathogen Magnaporthe oryzae. Overexpression of HDT701 in transgenic rice leads to decreased levels of histone H4 acetylation and enhanced susceptibility to the rice pathogens M. oryzae and Xanthomonas oryzae pv oryzae (Xoo). By contrast, silencing of HDT701 in transgenic rice causes elevated levels of histone H4 acetylation and elevated transcription of pattern recognition receptor (PRR) and defense-related genes, increased generation of reactive oxygen species after pathogen-associated molecular pattern elicitor treatment, as well as enhanced resistance to both M. oryzae and Xoo. We also found that HDT701 can bind to defense-related genes to regulate their expression. Taken together, these results demonstrate that HDT701 negatively regulates innate immunity by modulating the levels of histone H4 acetylation of PRR and defense-related genes in rice.

Jumonji C Domain Protein JMJ705-Mediated Removal of Histone H3 Lysine 27 Trimethylation Is Involved in Defense-Related Gene Activation in Rice

“…Recent studies in rice showed that overexpression of HDT701 (OsHDT1), a histone H4 deacetylase gene, in transgenic rice increases susceptibility to the rice pathogens Magnaporthe oryzae and Xoo. By contrast, knockdown of HDT701 in transgenic rice causes elevated levels of histone H4 acetylation and elevated transcription of defense-related genes and enhanced resistance to both M. oryzae and Xoo (Ding et al, 2012). Thus, HDT701-dependent histone H4 deacetylation plays a negative role in rice immunity to pathogen attack.…”

Plant-Specific Histone Deacetylases HDT1/2 Regulate GIBBERELLIN 2-OXIDASE2 Expression to Control Arabidopsis Root Meristem Cell Number

“…In the RM and elongation zone, HDT1/2 were located in both nucleolus and nucleoplasm (Supplemental Figures 5B and 5C), where they could alter the expression level of genes by changing chromatin acetylation levels (Wu et al, 2003;Zhou et al, 2004;Ding et al, 2012). We performed Illumina RNA sequencing to determine the transcriptome differences between the wild type and hdt1,2i-1 to obtain insight in how RM cell number might be reduced in hdt1,2i-1.…”

“…However, the function of HDTs in root development has not been investigated. It has been shown that HDTs are involved in responses to biotic and abiotic stress (Sridha and Wu, 2006;Bourque et al, 2011;Ding et al, 2012;Luo et al, 2012), and they can repress the expression of defense-related genes by altering their chromatin acetylation status (Bourque et al, 2011;Ding et al, 2012). We studied whether HDTs regulate the switch from cell division to expansion and in this way contribute to the mechanisms controlling RM cell number and subsequently root growth.…”

Arabidopsis HOOKLESS1 regulates responses to pathogens and abscisic acid through interaction with MED18 and acetylation of WRKY33 and ABI5 chromatin

“…global histone H4 acetylation and modulates defense-related genes in rice resistance to Magnaporthe oryzae and Xanthomonas oryzae pv oryzae (Ding et al, 2012). The elongator complex subunit 2 (ELP2) and ELP3 regulate resistance to P. syringae pv maculicola (Psm) ES4326 through their HAT activity on defense-related genes (Defraia et al, 2013;Wang et al, 2013).…”