Genome editing: a boon for plant biologists, breeders and farmers.

Abstract

logies have greatly bene fitted humankind in various fields. India attained food security through Green Revo lution in the mid-1960s–70s, which was a result of developing new high-yielding vari eties of wheat and rice introgressed with semi-dwarfing genes through conventional plant breeding methods. Consequently, food grain production increased substan tially in the country. Conventional plant breeding, which is entirely based on phe notypic selection, with limited knowledge of the associated gene(s) with the selected trait(s), is time-consuming and takes about 10–12 years to develop a new crop variety. Years of extensive research using DNA based molecular tools helped breeders to hasten the process of breeding by selection through molecular markers and shuttle breeding. Genetic variation is the key pre requisite for crop improvement. Since the accumulation of genetic variation due to spontaneous mutation is a very long pro cess, scientists learned to rapidly induce variation in DNA using physical or chemi cal mutagens. Mutation breeding generates random variation in the genome and has led to the release of more than 3200 plant varieties in 70 countries (IAEA database). However, obtaining desirable mutants through induced mutagenesis is time and labour-intensive. Further, to add new traits of economic importance, scientists discove red the methods of transferring genes from unrelated sources to plants, and subsequen tly, GM crop varieties were developed with several useful traits through the process of genetic engineering. In recent times, an unprecedented revolution has occurred due to the development of the novel technology called genome editing, which has emerged as a new breeding tool with enormous po tential. Genome editing allows modifica tions in an organism’s native DNA at a pre-determined genomic locus in a precise and targeted manner