草莓果实中蔗糖应答转录因子及其互作蛋白的分离及功能解析

Sucrose has been traditionally thought to be the structural and energy material,and in fruit, sucrose has been traditionally to be the ingredient tightly correlated with fruit quality. However, our recent work demonstrated that sucrose may function as a signal that plays important roles in strawberry fruit development and ripening. The reason for sucrose to regulate strawberry fruit ripening lies in that it may be able to control ABA signal production. Based on previous works, this project aims to further explore the mechanisms for sucrose signal transduction associated with the regulation of strawberry fruit development and ripening. With the signaling pathway of sucrose activated FaNCED expression as a clue, this project will first characterize the sucrose-responsive cis-element in FaNCED promoter. With the cis-element as a bait, we will further identify the sucrose responsive transcription factor, and further more, identify the transcriptor-interacting signal protein. Finally, through metabolic and transcriptional analysis, this project will further decipher the roles of and related mechanisms for the sucrose responsive transcription factor and its interacting protein in the regulation of strawberry fruit development and ripening. This project will not contribute to a better understanding of the molecular basis for strawberry fruit development and ripening, but also be of particular significance for genetic manipulation of fruit quality.

长期以来，蔗糖一直被认为是操纵植物生长和发育的结构和能源物质，而在果树果实发育过程中，糖也一直被认为是与果实品质关系密切的指标。但是，我们最近的研究表明，蔗糖可以作为信号分子在草莓果实发育及成熟过程中起着重要作用。蔗糖操纵草莓果实成熟的重要原因是操纵了ABA信号的产生。本研究旨在以往的工作基础之上，进一步解析蔗糖信号转导与草莓果实发育及成熟调控的关系。研究拟将以蔗糖操纵ABA合成关键酶（FaNCED）基因表达的信号传递链为线索，以FaNCED启动子中蔗糖响应元件的解析为突破口，分离与鉴定蔗糖应答转录因子，并在此基础上，进一步揭示与蔗糖应答转录因子互作的信号蛋白。最后通过代谢组和转录组分析等多种技术与体系，进一步深入解析蔗糖应答转录因子及其互作蛋白在草莓果实发育和成熟中的作用及机理。该研究不仅有助于深入了解草莓果实发育与成熟调控的分子基础，同时对今后果树品质改良的分子调控具有重要的指导意义。

草莓不仅是重要的果树，其产业的发展占有重要的经济地位，而且草莓日益成为研究果树果实发育、成熟和品质形成调控的模式植物。果树果实发育和品质形成受内因和外因的控制，内因即果实内源的原初信号，外因即环境因素。近年来的研究表明，植物激素ABA在草莓果实发育和成熟调控中起着重要作用，除ABA之外，蔗糖也可做为信号参与果实发育和品质形成的调控。本研究旨在以蔗糖信号转导机理为切入点，揭示草莓果实发育、成熟及品质形成调控的分子基础。研究的核心目标是揭示参与蔗糖信号转导的转录因子、作用元件和信号组分，揭示蔗糖和ABA信号转导的交叉对话。重要研究结果体现在以下几个方面: 一是围绕课题内容和工作目标，建立了一系列技术方法和体系；二是揭示了蔗糖应答的转录因子MYB10及其靶基因应答元件，如CHS,CHI，SPS和SUT 启动子等。此外，在基础上，揭示了MKK5/MPK12/MYB10核心信号模块，揭示了SnRK2可以作为节点信号，在蔗糖和ABA信号交叉对话中起着关键作用；三是揭示了SnRKs作为关键的信号组分，其所有成员和MAPK3/6都可形成互作关系，如此可介导多刺激及多个代谢体系的调控，在草莓果实成熟和品质形成中起着重要作用；四是揭示了SnRK2参与的完整信号通路,如ABA/PYR/ABI1/SnRK2/MAPK/MYB10/CHI等，其与RLK 信号系统存在交叉对话。到项目结题为止，共发表SCI论文9篇， 其中第一标注文章5篇。另有两篇高质量论文将于2019年完成。该课题的执行，对深刻了解草莓果实发育和品质形成的分子基础具有重要的意义。..关键词: 蔗糖信号，ABA信号，SnRK2, 草莓，果实发育