马铃薯块茎低温贮藏过程中酸性转化酶活性调控机制及其与低温糖化的关系

项目名称： 马铃薯块茎低温贮藏过程中酸性转化酶活性调控机制及其与低温糖化的关系

项目编号： No.30800754

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 宋波涛

作者单位： 华中农业大学

项目金额： 19万元

中文摘要： 马铃薯酸性转化酶Stinv1在马铃薯块茎低温糖化过程中起着重要的作用。为了明确块茎低温贮藏过程中酶活性调控方式，本研究通过对Stinv1上游启动子调控区域及互作蛋白进行了分离与鉴定，结果表明转化酶启动子中存在低温诱导、蔗糖诱导等调控元件；同时，酵母单杂交和EMSA分析表明，其基因地位诱导表达受CBF调节。通过酵母双杂交和双分子荧光定位分析表明，Stinv1蛋白与已知23个潜在蛋白存在互作，其中包括对其活性直接具有调控作用的StInvInh2和StubSNF1蛋白。基因功能分析表明，这两个基因均在转化酶的活性及马铃薯块茎抗低温糖化方面有一定的功能。转化酶、转化酶抑制子及SnRK复合体个亚基间的互作关系分析表明，环境因子变化，特别是温度变化，对这三者间所形成的蛋白复合体构想变化，可能改变转化酶及其抑制子间的结合，从而导致还原糖含量的变化。本课题研究结果从蛋白质与核酸互作和蛋白质与蛋白质互作的角度，阐明马铃薯块茎低温贮藏过程中转化酶调控网络及其与马铃薯抗低温糖化的分子机制，为通过转化酶的活性调节控制低温糖化提供理论支持和物质基础。

中文关键词： 马铃薯；酸性转化酶；蛋白互作；低温糖化

英文摘要： Potato acid invertase gene, Stinv1, plays an important role in cold-induced sweetening (CIS) of potato tuber. For the purpose of investigation mechanism regulating the activity of Stinv1 during cold storage of tubers, the promoter elements of Stinv1 and its interaction proteins were isolated and indentified. Low temperature response elements (LTRE) and sugar-repress-elements (SRE) were detected in the Stinv1 promoter. One transcription factor, StCBF1, was found to bind to LTRE by yeast-one-hybrid and EMSA analysis. 23 potential Stinv1-interaction-protein, including StInvInh2 and StubSNF1 which can regulate Stinv1 directly, were isolated by YTH and BiFc. Function analyzing of those two proteins proved the regulators of the enzyme activity of Stinv1 and contributions to reducing CIS. The model of Stinv1-StInvInh2-SnRK1 proteins complex shows that structure of the complex changing will lead to accumulation or consumption of reducing sugar according to environment stress. In protein-DNA and protein-protein interaction level, Our results elucidated the regulatory network of invertase and molecular mechanism of CIS which will theoretically and practically help us to breed potato varieties with processing quality through manipulating the invertase activity.

英文关键词： otato; Stinv; Protein interact; cold-sweetening