淀粉磷酸化酶在木薯淀粉合成多酶复合体中的功能研究

项目名称： 淀粉磷酸化酶在木薯淀粉合成多酶复合体中的功能研究

项目编号： No.31501353

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 食品科学、农学基础与作物学

项目作者： 赵姗姗

作者单位： 上海辰山植物园

项目金额： 20万元

中文摘要： 淀粉产量和品质是木薯首要的农艺性状，影响种植业和产业应用。解析淀粉合成关键酶的生物学功能并进行表达调控是改良淀粉的最有效手段。淀粉磷酸化酶(starch phosphorylase, SP)参与淀粉生物合成过程并影响其它关键酶的活性，进而影响淀粉结构与品质的机制还知之甚少。本项目拟对木薯储藏根发育过程中SP参与淀粉合成的生物学功能开展研究。利用SP过表达或RNAi的转基因木薯，研究储藏根发育过程中SP的基因表达模式、酶活及调控方式对淀粉合成代谢的影响。同时结合淀粉分支酶(SBE)干扰下调的高直链淀粉转基因木薯，研究SP与SBE等关键酶的互作对葡聚糖产物结构组分的影响，进而解析SP对高直链木薯淀粉粒的形态结构和淀粉富集的作用。同时获得一批淀粉产量和品质改良的新种质新材料。该课题成果将深化我们对木薯储藏根淀粉生物合成及调控机理的了解，并为木薯淀粉产量和品质改良提供依据和技术，推动木薯种质创新。

中文关键词： 木薯；淀粉合成；淀粉磷酸化酶；直链淀粉；基因功能

英文摘要： Starch yield and quality are paramount agronomic traits of cassava, affecting its farming and industrial applications. On the basis of functional study of key enzyme genes in starch biosynthesis, regulation the expression level of those genes is the most effective means for starch quality improvements. Starch phosphorylase SP may function in starch biosynthesis associating with the activities of other key enzymes, resulted in altered starch structure and quality. However little is known about the specific function of SP. The project intends to carry out research on the function and mechanism of action for SP in cassava starch biosynthesis at different development stages of storage root. Through efficient genetic transformation platform, transgenic cassava plants are obtained with over-expression and down-regulated expression level of SP gene specifically. Research are focused on gene expression pattern and the enzyme activity regulation of SP, and combined with studies of starch-related phynotypes in transgenic cassava, the function of SP in storage starch biosynthesis will be uncovered. Research is also carried on transgenic cassava with down-regulated expression level of SBE gene to study the interaction of SP and other key enzymes. Through studying the interaction between SP and SBE among protein complexes of key enzymes, integrated the results of structural characteristics of high amylose starch and various carbohydrates, the contribution of SP to high amylose starch granules morphogenesis and starch accumulation will be revealed. Meanwhile, we obtain a group of new varieties with improvement of starch yield and quality. The project will deepen our understanding of starch biosynthesis in cassava storage root and its regulatory mechanism, thus provide theoretical basis and technology for cassava starch yield and quality improvement research, and accordingly promote cassava germplasm innovation.

英文关键词： cassava;starch biosynthesis;starch phosphorylase;amylose;gene function