Insect Pest Management in Rice Through Genetic Engineering

Resistance breeding programs resulted in the successful development of rice cultivars expressing resistance to major insect pests of rice. However, the conventional breeding approach has provided only a moderate level of resistance for most of the insect pests. Genetic transformation of crop plants with insecticidal protein genes from unrelated organisms is a proven technology with potential for commercial success. In the absence of natural variability to resistance to lepidopteran rice pests (such as stem borers and leaf folders), transgenic plant technology offers a potent, quick, and environmentally friendly method of controlling these pests. The Bt genes derived from Bacillus thuringiensis are very effective in controlling the major lepidopteran pests of rice such as stem borers and leaf folders. The cry genes (such as cry1Aa, cry1Ab, cry1Ac, cry1Ab/cry1Ac fusion gene, cry1B, cry1C, cry2A, and cry2AX1) were shown to impart resistance to lepidopteran pests of rice. The possibility of employing non-Bt insecticidal proteins, such as lectins (carbohydrate-binding proteins), proteinase inhibitors, ribosome-inactivating proteins, secondary plant metabolites, small RNA viruses, etc., is also being investigated by several researchers Recently, CRISPR-based genome-editing tools have proved to be effective for pest management in rice.