栽培黄瓜资源中缺乏南方根结线虫抗性材料，利用感病基因功能丧失创制黄瓜抗根结线虫抗源材料，是黄瓜抗根结线虫育种的新策略。本项目拟围绕黄瓜CsMLO2基因对根结线虫侵染的免疫负调遗传机制，利用发根农杆菌介导黄瓜CsMLO2基因RNAi敲低和CRISPR/Cas9敲除转化须根系统，验证CsMLO2基因参与根结线虫侵染黄瓜感病反应调控功能；以膜受体CsMLO2为诱饵，采用细胞膜分裂泛素酵母双杂交技术，筛选鉴定CsMLO2膜受体感应南方根结线虫互作效应子蛋白，以及效应子信号传入细胞内后与其互作激活的靶标蛋白，从而解析膜受体CsMLO2蛋白接受并向细胞内传导根结线虫效应子信号途径，阐明黄瓜CsMLO2基因对根结线虫侵染的免疫负调遗传机制。以上创新性成果的获得对于丰富植物对根结线虫免疫学理论和发展黄瓜持久广谱抗性遗传控制新技术均具有重要意义。

To date, no Meloidogyne incognica (southern root knot nematode) resistance have been reported in the cultivated cucumbers. Loss of function of susceptible gene in cucumber is a new way for nematode resistance breeding. In this proposal, we focus on the negative regulation role of the cucumber CsMLO2 gene which may interact with M. Incognica effectors. First, loss and gain of CsMLO2 in the susceptible cucumber plants will be carried out by RNAi and CRISPR/Cas9 technology. Second, the effector in M. Incognica which may interact with CsMLO2 will be screened by membrane two-hybrid assay. The down-stream cucumber targets of CsMLO2 in the signaling pathway are investigated by the same method. The genetic mechanism of CsMLO2 that negatively regulate the cucumber immunity may arouse the light of using susceptibility genes in the cucumber breeding and develop the broad-spectrum and durable resistance against M. incognica.