ANALYSIS OF HOST-INDUCED RESPONSE IN THE RICE BLAST FUNGUS MAGNAPORTHE-GRISEA USING 2-DIMENSIONAL POLYACRYLAMIDE GEL ELECTROPHORESIS

Two-dimensional (2-D) polyacrylamide gel electrophoresis of proteins w as used to study the response of the rice blast fungus to extracts pre pared from resistant and susceptible rice cultivars. A protein of mole cular mass 31 kDa was induced by a susceptible host extract, while the fungus exposed to extract from the resistant cultivar and the untreat ed samples did not show the presence of this protein. Levels of this 3 1 kDa protein increased 30-fold, 72 h after treatment with plant extra cts, with the concomitant appearance of at least sixteen other novel p roteins. Fungus treated with extracts of resistant host or the untreat ed samples did not show any of these proteins while the proteins speci fic to different growth stages appeared as expected. Analysis of the e xtracellular samples showed induction of a 17 kDa protein after 72 h i n the culture treated with susceptible host extract. Since the resista nt host extract does not cause induction of any protein it is likely t hat the proteins induced in response to the susceptible host are expre ssed during the disease process and/or its establishment. Our study de monstrates usefulness of 2-D analysis in understanding host-pathogen i nteractions.