低温介导MdSIZ1调控苹果果实色泽品质形成的分子机理研究

项目名称： 低温介导MdSIZ1调控苹果果实色泽品质形成的分子机理研究

项目编号： No.31301763

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 李媛媛

作者单位： 山东农业大学

项目金额： 25万元

中文摘要： 果实色泽是果树的重要农艺性状，苹果果皮的颜色主要由花青素及其衍生物决定，温度是影响花青素合成的重要环境因素，但调控的分子机理至今不清楚。在前期研究中，申请人从苹果中克隆了响应低温信号的重要基因MdSIZ1，它是一个E3 SUMO连接酶，可将下游很多转录因子SUMO化，影响其蛋白稳定性；酵母双杂交证实MdSIZ1和MdMYB1能够互作，推测MdSIZ1可能通过调控MdMYB1蛋白稳定性影响花青素积累。为了验证该假想，本研究拟利用双分子荧光互补、免疫共沉淀和Pull-down技术验证MdSIZ1与MdMYB1的相互作用，并通过转基因和SUMO化分析等技术检测MdSIZ1对MdMYB1的SUMO化作用。最后，检测转基因苹果愈伤、组培苗，以及瞬时表达MdSIZ1的苹果果实中花青素的积累，揭示低温介导的MdSIZ1调控苹果果实色泽形成的分子机理。

中文关键词： 苹果；MdSIZ1；MdMYB1；花青苷；着色

英文摘要： Fruit coloration is an important agronomic trait for fruit tree. Anthocyanin and its derivatives are the main pigments that determine the fruit coloration. Temperature is one of the most important enviromental factors that induce anthocyanin biosynthesis, however, the regulating molecular mechanism remains unclear. Recently, the appliant isolated a low-temperature-responsive gene MdSIZ1 from apple fruit peel. MdSIZ1 encodes an E3 SUMO ligase gene, which mediates many downstream transcription factors sumoylation to regulate their protein stability. Intrestingly, yeast-two-hybrid assay showed that MdSIZ1 protein physically interacts with MdMYB1, which is a key activator for anthocynin biosynthesis and fruit coloration in apple, suggesting that MdSIZ1 may be involved in the regulation of apple fruit coloration by modulating MdMYB1. To verify this hypothesis, firstly, bimolecular fluorescence complementation (BiFC), co-immunoprecipitation, and pull-down assays are to be performed to check if MdSIZ1 protein interacts with MdMYB1 in vivo in plant cells. Secondly, transgenic and sumoylation techniques will be used to test the sumoylation of MdMYB1 by MdSIZ1. Finally, transgenic apple callus and plantlets, as well as apple fruits transiently expressing MdSIZ1 with a VIGS vector-mediated approach, are used to charaterize

英文关键词： Apple；MdSIZ1；MdMYB1；anthocyanin；coloration