Proteinase inhibitors: Plant-derived genes of insecticidal protein for developing insect-resistant transgenic plants

Proteinase inhibitors (PIs) are anti-metabolic proteins. which interfere wi th the digestive process of insects. It is one of the important defence str ategies existing in plants against predators. The use of the plant-derived PI genes for developing insect-resistant transgenic crops has come of age. Several transgenic plants expressing PIs have been created and these plants have shown enhanced resistance against insect pests. Recently PIs have als o been used to engineer resistance against viruses in transgenic plants. Th e current scenario for developing insect, fungal and viral pathogen-resista nt transgenic crops by using PI gene(s) is reviewed. The biosafety aspect o f the transgenic plants expressing PIs is also discussed.