Expression of cry genes from Bacillus thuringiensis: Influence on biochemical composition of transgenic cotton

Continuing need to increase agricultural production hasspurred the urge for developing cultivars with highproductivity and a high degree of resistance to insect pests.One of the factors constraining crop production is losses dueto insect pests, estimated at 14% of the total agriculturalproduction (US$ 250 billion), despite application ofinsecticides valued at $50 billion annually (Oerke 2006).However, many insect species, including cotton bollworm,Helicoverpa armigera (Hubner), have developed high levelsof resistance to conventional insecticides. Therefore, there isa need to harness all the technologies, including biotechnologyfor crop protection for a sustainable growth in agricultureand food security. To achieve a satisfactory control of insectpests, genes encoding d-endotoxins from Bacillusthuringiensis (Bt) have been deployed in a number of cropsincluding cotton, and approved for commercial cultivationin several countries. Because of the potential benefits ofgrowing genetically modified crops, their cultivation hasincreased from 1.97 million ha in 1996 to over 160 millionha in 2011 (James 2011). Cotton cultivars with Bt genes forresistance to cotton bollworm, H. armigera have resulted ina significant decrease in number of insecticide sprays appliedfor bollworm control in cotton, and increased cottonseedyield (Sharma et al. 2004, Sharma and Pampapathy 2006,Dhillon et al. 2012). Although, the promise of geneticallymodified crops has been realized in several crops and indifferent regions for increasing crop production, it is importantto address the concerns related to their impact on non-targetorganisms, biochemical composition and substantialequivalence to the conventional food

M K Dhillon, J Davis, H C Sharma, 'Expression of cry genes from Bacillus thuringiensis: Influence on biochemical composition of transgenic cotton', Indian Journal of Agricultural Sciences, vol. 83(12), pp.1388-1391, Indian Council of Agricultural Research, 2014