Source: CropBiotech Update

Sheath blight is a disease of rice that afflicts the crop in most rice-growing areas of the world. Caused by the fungus Rhizoctonia solani, sheath blight is controlled by fungicides, a practice which is neither practical nor sustainable, and causes damage to both human health and the environment. Genetically engineering R. solani resistance into rice is thus a promising approach for the management of sheath blight disease.

Krishnan Kalpana and colleagues of Tamil Nadu Agricultural University, India, take the steps toward this goal as they undertake “Engineering sheath blight resistance in elite indica rice cultivars using genes encoding defense proteins.” Their work appears in a recent issue of Plant Science. The authors aimed to develop rice cultivars with enhanced resistance to sheath blight by genetically transforming high yielding indica rice cultivars, ADT38, ASD16, IR50, and Pusa Basmati1 (PB1), with the rice tlp gene, which encodes a pathogenesis-related (PR) protein. PR proteins can enhance plant resistance to pathogens when over-expressed.

The researchers report that the engineered rice had increased resistance to R. solani when compared with non-transformed plants; and that resistance was enhanced when tlp was co-transformed with rice chi11, a gene encoding a chitinase, another anti-fungal protein. In addition to sheath blight resistance, the tlp or chi11 transgenic lines were also resistant to the rice sheath rot pathogen, Sarocladium oryzae.

Subscribers to Plant Science can read the complete article at http://dx.doi.org/10.1016/j.plantsci.2005.08.002