VDAC蛋白介导的线粒体调亡在野生甜瓜广谱抗白粉病中的作用及机制

Independent cell immune exist widely in plant and fungal interactions, under the attacks of fungi，the resistance of invasion is often accompanied by spontaneous cell necrosis, which makes other cells to survive before the infection. Our previous studies showed that CmMLO2 transmembrane protein, which located in the cell membrane of leaf, was one of the negative regulatory factors of powdery mildew, and its wild deletion mutant mlo relying on highlight fusion protein ROR2 could get a broad-spectrum resistance of powdery mildew. Through further induction powdery mildew on wild materials, display of the 2D-DIGE protein differential, identification of mass spectrum and the analysis of the informatics, we discovered that voltage dependent anion channel protein VDAC was high expression, and it was in the core position of protein regulation network. VDAC was the key protein which control permeability transition pore (MPTP) of mitochondrial membrane. We speculate that wild melon materials which had broad-spectrum resistance of powdery mildew were precisely controlled by VDAC.In this project, we will determine the mitochondrial membrane fluidity and membrane potential of wild resistant materials, analysis the function of VDAC gene, the expression of VDAC protein and the general character of plant mitochondrial apoptosis to clarify the broad-spectrum resistance mechanism of wild melon germplasm which have high resistance to powdery mildew through cytology, genomics and proteomics analysis.

细胞自主免疫广泛存在于植物-真菌互作中,在病菌攻击下,入侵抗性反应通常伴随着自发性的细胞凋亡,使得其他的植物细胞在侵染前得以存活。我们前期研究结果表明，定位在甜瓜叶片细胞膜上的CmMLO2跨膜蛋白是白粉病的负调控因子,它的野生缺失突变体mlo依赖突出融合蛋白ROR2，可以获得对甜瓜白粉病的广谱抗性。进一步通过对野生材料的白粉病诱导，2D-DIGE蛋白质差异显示、质谱鉴定以及信息学分析后发现，电压依赖型阴离子通道蛋白VDAC高量表达，且在蛋白质调控网络中处于核心地位，而VDAC是控制线粒体外膜通透性转换孔(MPTP)状态的关键蛋白，因此推测甜瓜白粉病广谱抗性野生材料是受控于VDAC的精确调控,本项目通过对野生抗性材料线粒体膜流动性和膜电位测定、VDAC基因功能分析，VDAC蛋白质谱表达分析以及植物线粒体调亡的共性认知，从细胞学、基因组学和蛋白组学三个层面解析甜瓜野生种质对白粉菌的广谱抗性机理

甜瓜白粉病是重要的田间病害，每年损失严重。本项目利用分子生物学技术，通过野生抗白粉病甜瓜种质资源，鉴定与白粉病免疫反应可能有关的VDAC蛋白基因，完成了 VDAC 基因的克隆和基因特征的生物信息学分析，通过构建荧光定位表达载体明确甜瓜 VDAC 蛋白在叶片细胞器中的定位和分布，通过 RT-PCR 技术， 研究了野生甜瓜和栽培甜瓜在白粉病诱导下的不同表达模式。通过 2-DE 差异蛋白分析结合生物信息学，解析 VDAC 蛋白在广谱抗性网络互作中的核心地位。 通过 VDAC 基因的反义遗传转化，结合线粒体结构特征的变化，明确了 VDAC 蛋白介导的线粒体调亡在甜瓜白粉病广谱抗性中的作用机制。