白粉病是西南地区富士苹果生产的主要病害之一。在拟南芥和大麦上研究表明WRKY转录因子调控白粉病的抗性，但苹果WRKY转录因子参与抗白粉病的调控机制目前还不清楚。我们前期从富士苹果中筛选到一个受白粉病菌和水杨酸强烈诱导WRKY转录因子MdWRKY40b，负调控苹果白粉病的抗性。以此为基础，本项目拟通过启动子活性分析、拟南芥基因互补实验和RNA干扰（RNAi）技术等，进一步研究MdWRKY40b转录因子的诱导表达因子和对白粉病抗性的调控功能。并通过染色质免疫共沉淀（CHIP）和转录组测序（RNA-Seq）技术，筛选和鉴定MdWRKY40b调控的靶基因，结合生物信息学分析和实时荧光定量PCR技术，阐明靶基因参与的生物学途径。综合以上研究，可以揭示MdWRKY40b调控白粉病抗性的功能及分子信号途径，为苹果分子抗病育种奠定基础。

Powdery mildew is one of the important diseases of ‘Fuji’ apple ( Malus domestica Borkh. cv. Fuji) in Southwest of China. WRKY transcription factors are known to involve the regulation of the resistance to powdery mildew in Arabidopsis and barley，however, the role of WRKY regulating the resistance to apple powdery mildew is unknown. In our previous research, a WRKY transcription factor in ‘Fuji’ apple strongly induced by Podosphaera leucotricha infection and SA treatment, and negative regulation of the resistance to the powdery mildew was cloned. In the next research, we intend to disclose the mechanism of MdWRKY40b regulating the resistance to the powdery mildew by analysis of the promoter activity, RNA interference and complementary experiment in Arabidopsis. The target genes of MdWRKY40b will be screened and identified by Chromatin Immuno-precipitation(ChIP) and RNA seq. By the analysis of qRT-PCR and bioinformatics of the target genes, the biological pathways of the regulation by MdWRKY40b will be elucidated. Combination of the above experiments and analysis, the functions and mechanism of MdWRKY40b in the regulation resistance to the apple powdery mildew will be disclosed.