To meet the food demand of the booming world population, the comprehensive requirements for yield, quality, and adaptability of crop cultivars are becoming more and more urgent. Due to the limitation of genetic variation within nature or mutagenized populations of sexually compatible species, conventional approaches to crop improvement, such as artificial selection, hybridization, and induced mutagenesis are laborious and time-consuming. However, transgenic technology surmounts hybridization barriers and utilizes the desirable genes from genetically distant species.

Transgenic cultivars are developed by cloning desirable genes, constructing expression vectors, genetic transformation of recipient crops, screening and identification of transformed lines, so as to improve the original undesirable traits or endow them with new beneficial traits3. In addition, transgenic technology is also used to modify or knock out the undesirable genes of crops to change their genetic characteristics and obtain the desirable phenotypes.

Advancements in gene transfer technology have indeed opened up exciting possibilities for more effectively manipulating the genetic makeup of live organisms, ranging from microorganisms to plants and animals. Successful gene transformations were reported in many crops conferring tolerance to various environmental and biotic stress factors. The gene transfer techniques like Agrobacterium-mediated transformation, microinjection, and particle bombardment have been used to develop new varieties with improved growth and yield characteristics. These techniques allow for precise and controlled addition of genes to the genomes of targeted hosts. In this context, a study was conducted to develop resistance against Alternaria leaf spot in Brassica juncea, the barley antifungal genes class II chitinase and type I ribosome-inactivating protein (RIP) were coexpressed in Indian mustard via Agrobacterium-mediated transformation1. Similarly, a transgenic cotton variety Narasimha (NA1325) was developed by introducing three Cry genes driven by three different promoters conferring resistance to lepidopteran insects2.

While transgenic approaches have been applied successfully in many crops to improve a wide range of traits to date but only a small number of these plants have made it to market due to poor public perception, as well as the exorbitant cost and duration of existing regulatory processes. As research and technology continue to advance, the role of transgenics in crop improvement will undoubtedly become even more integral, fostering a future where agriculture is more resilient, efficient, and capable of meeting the challenges posed by climate change and resource limitations.

References:

1.CHHIKARA, S., CHAUDHURY, D., DHANKHER, O. P. AND JAIWAL, P. K., 2012, Combined expression of a barley class II chitinase and type I ribosome inactivating protein in transgenic Brassica juncea provides protection against Alternaria brassicae. Plant Cell Tissue Organ Cult., 108: 83-89.

2.KATTA, S., TALAKAYALA, A., REDDY, M. K., ADDEPALLY, U. AND GARLADINNE, M., 2020, Development of transgenic cotton (Narasimha) using triple gene Cry2Ab-Cry1F-Cry1Ac construct conferring resistance to lepidopteran pest. J. Biosci., 45(1): 31.

3.RAYMOND PARK, J., MCFARLANE, I., HARTLEY PHIPPS, R. AND CEDDIA, G., 2011, The role of transgenic crops in sustainable development. Plant Biotechnol. J., 9(1): 2-21.