Enhanced sheath blight resistance in transgenic rice expressing an endochitinase gene from Trichoderma virens

The 42-kDa endochitinase (cht42) gene from the mycoparasitic fungus, Trichoderma virens, driven by CaMV 35S promoter, was introduced into rice by Agrobacterium-mediated transformation. Eight transgenic plants harboring single copies of complete T-DNA were identified by Southern blot analysis. Homozygous transgenic plants were identified for five lines in the T(1) generation by Southern blot analysis. Homozygous T(2) plants constitutively accumulated high levels of the cht42 transcript, showed 2.4- to 4.6-fold higher chitinase activity in total leaf extract and 1.6- to 1.8-fold higher chitinase activity in the extracellular fluid. Infection assays performed on the homozygous T(2) plants with Rhizoctonia solani showed up to 62% reduction in the sheath blight disease index.