RAJASEKHAR PINNAMANENI, N.S. REDDY, K.R.S. SAMBASIVA RAO
Abstract
Both chemical and microbial insecticides are currently used for insect control. A class of insecticidal proteins known as 8-endotoxins, are produced as parasporal crystals by Bacillus thuringiensis in nature. These proteins are quite selective in their toxicity to specific organisms. The crystal proteins are produced as large protoxins. The protoxins gets activated by the insect's digestive enzymes and binds to specific receptors in the insect midgut and brings about cell lysis by formation of pores. These naturally occurring insecticidal proteins have been commercially produced and used as insecticides. Bt preparations are used as crystal powder formulations under the trade name Dipel and Thuricide. Recombinant DNA technology has provided the opportunity of expressing these biocidal proteins in various organisms. Transgenic plants hold great promise as an important new tool in integrated pest management programmes. This technology allows the crop plant to deliver its own means of protection againstinsect attack. Because of the environmental pollution and associated toxicity with chemical insecticides, biological insect control has a bright future but it may create various problems like Arthritis in humans, extra toughness in weeds etc.