Project description:Cucumber (Cucumis sativus L.) is an economically important vegetable crop distributed in over 80 countries. Downy mildew (DM) caused by the obligate oomycete Pseudoperonospora cubensis is especially destructive in cucumber production. So far, few studies on the changes in proteomes during the P. cubensis infection have been performed. Using a newly developed TMT-LC-MS/MS analysis, the proteomes of DM-resistant variety ‘ZJ’ and DM-susceptible variety ‘SDG’ under the P. cubensis infection were investigated. In total, 6400 proteins were identified, 5629 of which were quantified. The differential accumulated proteins (DAPs) exhibited various biological functions and diverse subcellular localizations. KEGG enrichment analysis showed that various metabolic pathways were significantly altered under the P. cubensis infection, such as terpenoid backbone biosynthesis, and selenocompound metabolism in ZJ, and starch and sucrose metabolism in SDG. Most of the enzymes associated with terpenoid backbone synthesis were significantly accumulated in ZJ rather than in SDG, suggesting that pathogen-induced terpenoids accumulation might play an important role in the resistance against P. cubensis infection. Furthermore, a number of pathogenesis-related proteins and heat shock proteins were identified as DAPs, suggesting that DM resistance was controlled by a complex network. Our data allowed us to identify and screen more potential proteins related to the DM resistance.
