Proteomic analysis of proteins in rice seedling
To determine a protein’s underlying difference between resistant and susceptible cultivars, all proteins were extracted from a 2-week rice seedling of both resistant and susceptible cultivars and then subjected to two-dimensional electrophoresis (2-DE). Highly reproducible protein spots across an 18 cm strip of PI 3-11 NL and molecular weight range 245-11 kDa were detected on CBB staining, shown in Fig.1. Nineteen different protein spots were observed between resistant and susceptible cultivars. These differentially regulated protein spots were successfully identified using LC-MS/MS analysis, followed by a Mascot database search of Oryza sativa in the NCBI database (Table 1). Among the 19 proteins, only two proteins were detected in the resistant cultivar (spots 18, 19), which were identified as proteins related to carbohydrate metabolism. Four proteins (spots 1, 2, 3 and 4) were up-regulated in the resistant cultivar involved in the stress response, antioxidant and protein synthesis. Thirteen spots (spots 5-17) showed high expression