观赏海棠叶片转色过程中DNA去甲基化途径修饰花色素苷代谢途径研究

Exploiting the anthocyanin biosynthesis in crabapple during the leaf development is important to reveal the molecular mechanism of color formation of Malus species. Several researches showed that DNA demethylation is widely involved in the several plant growth and development processes, and plant anthocyanin biosynthesis pathway may be modified by DNA demethylation pathway. In this study, we plan to reveal that demethylation pathway regulate anthocyanin biosynthesis which is mediated by DNA demethylation during leaf color transformation in Malus crabapple. Firstly, to determine the relationship between the expression level of demethylation genes and anthocyanin accumulation during leaf color transformation, we will use spring-red cultivars as materials to analyze the related indices. Furthermore, genetic transformation in homologous and heterologous organization, protein interaction and protein-promoter interaction are used to determine the regulation mechanism of DNA demethylation genes on anthocyanin biosynthesis related genes. Ultimately, we expect to build the regulation model of anthocyanins biosynthesis pathway which is regulated by DNA demethylation and provide theoretic and technical basis in the color formation of crabapple.

探索观赏海棠变色叶品种叶片转色过程中花色素苷代谢分子机理，对揭示苹果属植物彩叶成色机理和辅助分子育种意义重大。近年来的研究表明，DNA去甲基化基因能够广泛参与植物生长发育进程中，并存在调控植物色泽发育的潜在可能。因此，本课题旨在揭示DNA去甲基化修饰作用调控观赏海棠叶片转色过程中花色素苷代谢的机理。研究主要通过分析去甲基化关键基因表达和花色素苷积累的相关性，探究DNA去甲基化修饰基因是否参与观赏海棠叶片转色过程花色素苷代谢调节；并进一步通过遗传转化同源和异源组织、蛋白互作、蛋白与靶基因启动子结合研究，确定DNA去甲基化修饰关键基因在观赏海棠叶片转色过程中对花色素苷生物合成相关基因的作用方式。最终建立DNA去甲基化修饰对观赏海棠花色素苷代谢的调控模型。以期待为观赏海棠叶色发育、彩色品种的遗传改良提供理论基础和技术支撑。

探索观赏海棠变色叶品种叶片转色过程中花色素苷代谢分子机理，对揭示苹果属植物彩叶成色机理和辅助分子育种意义重大。近年来的研究表明，DNA去甲基化基因能够广泛参与植物生长发育进程中，并存在调控植物色泽发育的潜在可能。本研究中，本课题组通过转录组研究，发现苹果果实在低温条件下，DNA去甲基化基因MdROS1的表达水平与花色素苷积累趋势，及花色素苷生物合成基因的表达趋势一致。亚硫酸氢基因组测序结果表明MdCHS, MdCHI, MdF3’H, MdANS, MdUFGT和MdMYB10基因启动子甲基化水平在低温处理后，逐渐下降。苹果果实中也有类似的结果。在苹果叶片和果实中瞬时沉默抑制了MdROS1花色素苷的积累，并导致了花色素苷生物合成基因表达水平的降低，相反的结果出现在过表达MdROS1叶片和果实中。启动子结合试验表明，MdROS1的RRD-DME结构域能够直接结合MdF3’H和MdUFGT基因启动子。这些结果表明，DNA去甲基化关键基因，ROS1在低温条件下，能够通过影响花色素苷生物合成基因启动子的甲基化水平，调控低温诱导的花色素苷积累。本项目目前发表SCI论文8篇，中文论文1篇。获批发明专利2项，获得省部级科技奖励2项。