果实响应病原菌侵染分子机制是一个重要科学问题，磷酸肌醇(PIs)是植物响应环境胁迫的重要信号转导因子，而果实中PIs响应真菌病原菌侵染的分子机制尚不清楚。灰霉菌(B.cinerea)所引发的灰霉病为果实重要病害，本项目以八倍体草莓为研究对象，在前期PI(4,5)P2、PI4P和PI3P相关研究成果基础上，围绕草莓果实PIs响应灰霉菌侵染作用机理这一核心科学问题，在解析草莓PIs代谢网络的基础上，通过体外病原菌接种从分子水平和基因水平两个层面，探究果实响应灰霉菌侵染中PIs水平变化及其关键代谢节点的调控；并采用RNAi基因沉默技术构建PIs代谢下调果实模型，对其在灰霉菌侵染后抗性反应体系进行全面分析，进而揭示PIs代谢对果实抗病性的影响，明确PIs水平与果实各抗性因子的关系。本项目研究结果将进一步丰富草莓果实响应灰霉菌侵染的分子机制，为开发新型果实灰霉病防控生物技术提供理论依据和技术支撑。

The molecular mechanism of fruit against pathogen infection is a vital scientific issue. Phosphoinositides (PIs) are important signal transduction molecules of plants in response to environmental stresses. However, the molecular mechanisms of how fruit against fungal pathogens is still not clear. The gray mold caused by B. cinerea is the most important fruit disease. Based on our primary study on PI(4,5)P2、PI4P and PI3P, this study is focused on the molecular mechanisms of PIs in response to B. cinerea infection in strawberry (Fragaria×ananassa, Duch.). After establishing the PIs metabolic network of strawberry fruit, in vitro pathogen inoculation is used to explore the key PIs level alternation and their metabolic changes in response to B. cinerea infection via the molecular level and gene expression analysis. RNAi gene silencing technique is applied to construct the fruit model of down-regulated PIs metabolism. The resistance reaction system of the fruit model is comprehensively analyzed, to reveal the effect of PIs on the disease resistance of fruits, and to explore the relationship between PIs and other defense factors. The results of this study will further enrich the molecular mechanisms of strawberry fruit against the infection of B. cinerea. Additionally, it provides important theoretical basis and technical support for the development of new biological technologies for the control of gray mold.