果实发育和品质调控是果树研究领域的重要工作，而蔗糖代谢在果实发育中起着重要的作用。蔗糖合成酶是蔗糖代谢路径中的一个关键酶，具有合成和分解蔗糖两方面的功能，但是目前未有关于蔗糖合成酶在葡萄果实中如何调控蔗糖代谢进而参与果实发育的报道。为此，本项目拟在生理及分子水平上研究: 蔗糖和蔗糖信号对果实发育的影响；不同发育阶段和昼夜周期葡萄果实蔗糖合成酶的活性分布特点；在活体与离体条件下分析外界因素对果实中蔗糖合成酶活性的影响；分析蔗糖合成酶的合成和分解方向在果实发育不同阶段的功能；进一步通过原核表达蔗糖合成酶活性位点分析、番茄转基因功能验证和酵母双杂交分析互作蛋白等技术，阐述葡萄蔗糖合成酶的功能。本研究的开展与完成有助于认识蔗糖合成酶在葡萄果实发育和品质形成中的作用机理，为更好地调控葡萄果实品质提供理论依据。

Development and regulation on fruit quality is an important work in fruit research area. The sucrose plays very important roles during the development of fruit, and sucrose synthase (SS), a key enzyme in the sucrose metabolic pathways, involves in both synthesis and decomposition of sucrose. However, there are rarely detailed reports about how sucrose synthase regulates the sucrose metabolism in, and involves in the development of grape berry. In this project, we will study, at physiological and molecular biological levels, the following: The influence of sucrose and sucrose signal on the growth and development of grape; the distribution of sucrose synthase activity at different grape berry developmental stages and its day-night rhythm situation; analysis of the influence both of external and internal factors on the activity of sucrose synthase in vivo and in vitro; analysis of the function of the synthesis and decomposition activities of SS during grape berry development; analysis of the active locus of SS with technology of prokaryotic expression, function analysis with tomato transgenic, and analysis of the proteins acted with SS using yeast two-hybrid system. The results from this project will definitely do great help to our understanding the mechanism that sucrose synthase involves in the development of grape berry and quality formation, and provide us the theoretical basis for better regulation of berry quality.