Screening And Identification Of Resistance Related Proteins From Apple Leaves Inoculated With Marssonina Coronaria (EII.&J. J. Davis)

Marssonina apple blotches caused by the fungus Diplocarpon mali is a devastating defoliating diseasewhich do harm to the apple industry. In this study, with the material of resistant variety ‘Qinguan’, theapple leaves were inoculated with Marssonina coeonaria and the differentially induced proteins wereanalyzed via two-dimensional (2-D) gel electrophoresis to obtain potentially resistant proteins and theirpossible role in Marssonina apple blotch resistance mechanism were also discussed. The main results wereas follows:1. The Marssonina coeonaria induced differentially accumulated proteins were obtained via2-D gelelectrophoresis. A total of81protein spots showed significantly differential change in abundance.Fifty-nine protein spots were identified successfully by peptide digestion followed by TOS/MS;2. The59successfully identified protein spots were classified into nine functional categoriesaccording to the biological process, including photosynthesis (12spots,19%), amino acid metabolism(three spots,5%), transport (four spots,7%), energy metabolism (two spots,3%), carbohydrate metabolism(12spots,20%), binding (eight spots,14%), antioxidant (two spots,3%), defense and stress (11spots,19%)and unknown (five spots,8%);3. Subcellular localization of identified proteins was determined.34differentially accumulatedproteins were localized into chloroplasts (58%), and five were localized into mitochondrion (8%), one waslocalized into nucleus (2%), nine were localized on cytoplasm (15%), one was localized on the cell wall(2%). Three were localized to the extracellular (5%). Localization of the other proteins could not bedetermined (10%);4. In order to determine the correlation between levels of expressed protein and their correspondingmRNA, the relative expression of four resistant genes was assessed via Quantitative real-time PCR.Variation in mRNA levels of class III endo-chitinase and beta-1,3-glucanase exhibited a good relationwith the proteomic accumulation level. The mRNA abundance of thaumatine-like protein and ascorbateperoxidase were inconsistent with the proteomic level.