菊花品种资源丰富，花色多样，芽变是其花色多样性的重要来源。但芽变产生的方式及其调控花色形成的分子机理尚不明确。花青素和类胡萝卜素是决定菊花呈色的重要色素物质，分子遗传学研究表明，序列变异和甲基化是调控两类色素代谢的重要机制。课题组前期获得了一系列稳定的菊花花色芽变突变体，包括兼六香系列的白、黄（含类胡萝卜素）、粉（含花青素）和红色（两者兼有）品种。本申请在进行了上述品种转录组测序的基础上，首先通过基因表达分析获得两类色素代谢的节点基因，继而分离其DNA和启动子序列，找出序列变异（插入缺失、SNP、转座子、可变剪接等），通过序列删截与活性分析、酵母杂交、双荧光素酶实验、转基因等技术研究序列变异调控节点基因转录的机理。对于非序列差异引起的基因表达差异，进行启动子区甲基化检测，从表观遗传角度解释菊花花色芽变突变体形成的机理。研究成果有助于阐明菊花花色变异的分子调控机制，为定向改良其花色奠定基础。

Chrysanthemum is a famous ornamental plants with rich germplasm resources and variation of flower color. Bud mutation is the main reason for the color diversity, but the regulation mechanism of bud mutation of chrysanthemum is still unknown. Anthocyanidins and carotenoid are the main pigments that lead the flower color of chrysanthemum. It is proved that the regulation of these pigments is relevant to sequence variations and DNA methylation. We have got a series of bud mutations of chrysanthemum ‘Jianliuxiang’, including white, yellow (accumulate carotenoid only), pink(accumulate anthocyanidins only) and red (accumulate both pigments). On the basis of transcriptome analysis of these mutations, in this study, we will select the key genes which regulate the pigments pathways used gene expression analysis technology, the DNA sequence and promoter region will be isolated for analyzing the correlation between the sequence variations (Indel, SNP, transposon insertion and alternative splicing) and gene expression of the key genes. The dual luciferase assay, promoter deletion analysis, yeast one-hybrid assay, transgenic technology will be further used for the analysis of their function. Methylation levels of these genes will also be investigated to understand molecular mechanism for coloration unrelated with the sequence variations from epigenetics perspective.The research will clarify the regulation mechanism of flower color variations of chrysanthemum, and provide possibility for flower color directional breeding.