Transgenic approach in crop improvement

Crop improvement is essential to attain world food security and enhance nutrition for human beings. For a long time, conventional breeding has contributed toward crop improvement, but in the last three decades, the revolution of molecular breeding has arrived in crop improvement, which speeds up the process. Although traditional crop improvement methods are working, they are unable to fulfill the demand of a growing population. So, advanced molecular techniques such as transcription activator-like effector nucleases (TALENs), zinc-finger nucleases (ZFNs), and clustered regularly interspaced short palindromic repeat (CRISPR) came into the picture to provide more specificity. Genetic engineering (including transgenic) facilitates the transfer of desired characteristics into other plants, which is not possible through conventional plant breeding. Through genetic engineering, scientists have developed several crop plants that are resistant to multiple stresses such as abiotic and biotic stresses as well as herbicide tolerance. The major genetically modified (GM) crops cultivated are tomatoes, wheat, alfalfa, rice, soybeans, maize, canola, squash, brinjal, tobacco, cotton, sugar beets, petunias, sweet peppers, and carnations. Apart from food/resources, GM crops are used to remove heavy metals from the soil, which can rehabiliate waste land for use in agriculture. To accept GM crops, there are legal, social, and political barriers involved. Still, people have shown their interest in opting for GM crops. In this chapter, we comprehensively discuss the role of the transgenic approach in crop improvement to attain sustainable agriculture under changing environmental conditions and also focus on the commercial aspects of transgenic cotton and brinjal.