叶片早衰严重制约水稻的产量和品质。已有研究发现水稻ONAC011是叶片衰老正调控因子，但其转录激活的分子机制仍不清楚。我们前期工作表明，在水稻剑叶衰老期ONAC011的表达量与其基因座的H3K9ac富集正相关，同时组蛋白乙酰基转移酶OsHAC703的转录水平在此时期也显著上调，OsHAC703的CRISPR/Cas9编辑突变体呈现与ONAC011突变体相似的叶片持绿表型，且在oshac703突变体中ONAC011基因表达量显著下降。基于此，本项目拟以水稻OsHAC703过表达、敲除突变体及野生型为材料，采用ChIP-qPCR和qRT-PCR及ChIP-Seq和RNA-Seq技术，探明OsHAC703与ONAC011基因座H3K9ac和ONAC011转录的相关性，及其在叶片衰老中的调控作用，以阐明OsHAC703调控ONAC011转录和叶片衰老的分子机理。

Rice is the main food crop and the early senescence of flag leaf usually limits grain yield and quality. It is reported that ONAC011 acts as a positive regulator of leaf senescence in rice, but its regulatory mechanism at transcriptional and epigenetic modification level remains elusive. Our previous study showed the expression pattern of ONAC011 was associated remarkably with the dynamic changes in histone acetylation (H3K9ac) levels at ONAC011 loci during senescence of rice flag leaf. OsHAC703, encoding a histone acetyltransferase, also displayed an increased expression pattern during age, suggesting that OsHAC703 had significant positive correlation with H3K9ac levels and gene expression of ONAC011 during rice leaf senescence. The OsHAC703 Crispr/cas9 editing mutant showed stay-green phenotype as the onac011 mutant. This aim of this project is to clarify the mechanism of OsHAC703 regulates gene expression of ONAC011 and leaf senescence in rice. (1) to analyze the correlation of OsHAC703 with H3K9ac modification at ONAC011 loci, gene expression of ONAC011, as well as leaf senescence by chromatin immunoprecipitation qPCR (ChIP-qPCR) and qRT-PCR in OsHAC703 overexpression-, knock-out mutant and wide-type plants; (2) To identify the downstream senescence-associated genes and the effect of OsHAC703 on H3K9ac modification in a genome-wide scale by ChIP-Seq and RNA-Seq.