组蛋白去乙酰化酶GhHDA6调控棉花开花期的分子机制

早熟性是棉花育种中最重要的目标性状之一，与开花期紧密相关。组蛋白去乙酰化酶在植物生长发育中具有重要作用，但未见其调控棉花开花期的相关报道。前期研究中，我们通过QTL定位结合转录组和qRT-PCR结果，得到一个与拟南芥组蛋白去乙酰化酶基因AtHDA6高度同源的基因Gh_D03G0986（GhHDA6），该基因在花器官和茎中高量表达。过表达该基因促进拟南芥开花提前，VIGS沉默该基因使开花期推迟6天左右，表明GhHDA6在棉花开花进程中起着重要的作用。本研究拟通过过表达及CRISPR/Cas9基因编辑技术，明确GhHDA6的生物学功能；通过酵母双杂交文库筛选其互作蛋白，明确其是否形成多亚基复合体；联合分析RNA-seq、CHIP-seq和组蛋白乙酰化修饰数据探究其调控下游基因的分子机制，最终明确GhHDA6通过组蛋白去乙酰化影响棉花开花期的调控网络，为棉花早熟分子改良提供理论和材料支撑。

Earliness is one of the most important goal of cotton breeding and is closely related to flowering period. Histone deacetylase plays an important role in plant growth and development, but there is no report on its regulation of cotton flowering period. In the previous study, a gene Gh_D03G0986 (GhHDA6) was homologous to Arabidopsis histone deacetylase 6 gene (AtHDA6), was identified in the interval by combining function annotation, transcriptome and qRT-PCR data, which were highly expressed in flower organs and stems. Compared with WT lines, the flowering time of Arabidopsis overexpression lines of this gene was significantly promoted. Virus-induced gene silencing (VIGS) of GhHDA6 in normal plants caused reduced GhHDA6 gene expression levels, delayed flowering time about 6 days, and no difference in plant architecture and plant height. These results suggested that GhHDA6 might play an important role in the flowering process of cotton. In this project, the biological function of GhHDA6 in the flowering period of cotton will be illuminated by overexpression and CRISPR/Cas9 gene editing technology. The interaction proteins were screened by a yeast two-hybrid library to determine whether they formed multi-subunit complexes. RNA-seq, Chip-seq and histone acetylation modification data were used to explore the molecular mechanism of GhHDA6 regulating downstream genes. Finally, it was determined that GhHDA6 influences the regulation network of cotton flowering period through histone deacetylation, which provides theoretical and material support for early-maturing molecular improvement of cotton.