膜感应蛋白Sho1对梨果表皮蜡质物化信号诱导Alternaria alternata附着胞形成的调控机理研究

果皮蜡质的物化特性对病原真菌侵染结构分化具有诱导作用。我们研究发现MAP激酶AaHog1对梨果皮蜡质信号诱导Alternaria alternata附着胞形成具有调控作用，其上游膜感应蛋白AaSho1参与了诱导过程，但具体调控机制不清。本项目在对梨果黑斑病菌A.alternata Sho1基因克隆及生物信息学分析的基础上，采用显微技术、生物化学和分子生物学方法，通过构建AaSho1缺失突变株及回复菌株，比较分析ΔAaSho1突变株生长、胁迫响应、次生代谢和致病特性的差异；研究AaSho1对梨果表皮蜡质物化信号（疏水性、蜡质组分）诱导A.alternata附着胞形成的调控作用，同时明确AaSho1与AaHog1在A.alternata响应果皮蜡质信号中的协同调控模式。为全面揭示A.alternata感知和响应梨果表皮信号进而启动侵染的机制和开发梨果采后病害控制新方法提供理论依据。

Physic-chemical properties of fruit cuticular wax have a vital role in inducing infection structure differentiation of pathogenic fungi. Our previous results indicated that MAP kinase AaHog1was required in sensing cuticular wax cues from pear fruit during appressorium formation of Alternaria alternata, and its upstream sensor protein Sho1 was also involved in this process, however the detailed regulatory mechanism remains unclear. In this study, based on identifying, cloning and bioinformation analyzing for membrane sensor protein Sho1 from A. alternata, the causal agents of pear black spot, sho1 mutant (ΔAaSho1) and complementary strain in A. alternata will be generated, and vegetative growth, stress response, secondary metabolism and virulence of ΔAaSho1 strain will be analyzed compared with the wild type strain by the means of microscopic, biochemical and molecular methods; the regulatory role of AaSho1 on appressorium formation induced by pear cuticular wax physic-chemical cues (hydrophobicity and chemical composition) will also be evaluated. In addition, the regulatory crosstalk between Sho1 and AaHog1 on A. alternata responding to cuticular wax of pear fruit will be further confirmed. The results will provide a theoretical basis for further uncovering mechanism of A. alternata sensing and responding to physic-chemical signaling from pear fruit surface and then initiating infection, and exploiting novel strategies for controlling of postharvest diseases in pear fruit.