Abstract: Two-dimensional gel electrophoresis were employed to analyze the proteome from leaves of cucumber R17 at 24, 48 and 72 h, after inoculating Sphaerotheca fuliginea. The results showed that there were significant differences between inoculated plants and control in the 2-DE map. Seven different proteins of R17 seedling leaves with qualitative changes or relatively high abundance were identified by MALDI-TOF/ TOF searching NCBI, including a protein of putative phosphatidylinositol-4-phosphate 5-kinase, hypothetical protein g5bf, LHCⅡ type I chlorophyll a/b-binding protein, ferredoxin-NADP(H) oxidoreductase, putative XS domain containing protein, unconventional myosin XI and malate dehydrogenase. This study gives new insights into pathogen stress response in cucumber leaves and demonstrates the power of the proteomic approach in plant biology studies.

Key words: cucumber, powdery mildew, two-dimensional gel electrophoresis, mass spectrometry