Here, we first demonstrate that identification of rice brown spot disease fungus (Cochliobolus miyabeanus, C. miyabeanus) proteins is possible in infected tissues using in planta apoplastic proteome with non-destructive tissues. In planta apoplastic proteins from rice leaves inoculated with C. miyabeanus, CM2 (compatible race), were isolated by vacuum infiltration with CaCl2/Na-acetateextractionbuffer, separated by SDS-PAGE, and identified by MudPIT. Of the 529 proteins that were identified by MudPIT, a large proportion (490) was from the rice. Numerous carbohydrate metabolic process (48), oxidation and reduction (44), response to oxidative stress (20%) were identified and confirmed their expression at RNA levels using microarray. Bioinformatic analysis showed that 176 and 39 of these proteins have a signal peptide in rice and rice brown spot fungus, respectively, using Signal P. The large proportion of proteins interestingly identified from the in planta apoplast were involved inprotease, hydrophobin, and host cell wall hydrolysis (Xylanase, beta-glucosidase) derived from pathogen. Thus, we suggest that in planta rice apoplastic secretome will be an important clue to understand the rice-rice brown spot fungus interactions.

• U G Kim(Department of Plant Bioscience, Pusan National University)
• Soon Jae Kwon(Department of Plant Bioscience, Pusan National University)
• Yiming Wang(Environmental Biotechnology National Core Research Center, Gyeongsang National University)
• Sang Gon Kim(Environmental Biotechnology National Core Research Center, Gyeongsang National University)
• Kyu Young Kang(Environmental Biotechnology National Core Research Center, Gyeongsang National University, Division of Applied Life Science (BK21 Program), Gyeongsang National University, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University)
• Sun Tae Kim(Department of Plant Bioscience, Pusan National University) Corresponding Author