Sheath blight caused by Rhizotonia solani is described as the second major disease affecting rice. Genetic resistance to R. solani the ideal control measure is hampered because of the difficulty in identifying adequate resistance sources under typical selection conditions. Proteomic analysis techniques using two-dimensional gels (2D-PAGE) allow the study or monitoring of global changes in protein expression under normal and stress conditions. In this work, we compared rice leaves protein expression patterns of two Venezuelan varieties 12, 24 and 48 h after inoculation with R. solani. Approximately 400 and 300 protein spots stained with Sypro Ruby were reproducibly resolved across gel replicates, for PALMAR and FONAIAP-2000, respectively. Forty proteins out of a total 49 were identified for PALMAR variety, with thirty-two up-regulated protein spots and 8 down-regulated. Twenty-six protein...