Proteomic Analysis of the Resistant Responses of Two Vitis amurensis Cultivars to Plasmopara viticola Infections

Leaves of Vitis amurensis ‘Shuangyou’ (susceptible) and ‘Shuanghong’ (resistant) were inoculated with Plasmopara viticola, the causal agent of downy mildew in grapevine. Key proteins regulated in the response to downy mildew infection were analyzed by differential proteomics and MALDI-TOF/TOF. The leaf proteome changed differentially between the two cultivars following injection by P. viticola. More than 300 protein spots were detected, among which nine differentially expressed proteins were identified. The functions of the identified proteins comprised secondary metabolism, structure, photosynthesis, energy production, and resistance. In the resistant cultivar, photosynthesis proteins and ATP synthase might be down-regulated to restrict fungal growth, and the pathogenesis-related protein 10 may be upregulated to limit the extent of spread of the fungus. Pathogenesis-related protein 10 is proposed to be a key protein in the response of Vitis amurensis to downy mildew infection in the resistant cultivar.