Recent Transgenic Approaches for Stress Tolerance in Crop Plants

Abstract

Exacerbation of plant growth and productivity due to a wide range of stresses has significantly affected global food security, agricultural productivity, and quality worldwide. In order to bridge the gap between the supply and demand of the ever-increasing global population, it is indispensable to foster a new breed of stress-tolerant crops with refined traits and higher yields against several abiotic and biotic stresses. The transgenic approach of conventional breeding, owing to the limited and time-consuming success due to the complex nature of genes involved in stress tolerance, is now being widely adopted to breed crop plants with enhanced stress tolerance. Thus, identification and characterization of critical genes involved in abiotic and biotic stress tolerance are an important requisite to develop stress-tolerant crops. Genetic engineering of crop plants employs two strategies (i) either manipulating single functional gene or (ii) by editing those regulatory genes which modulate the expression of other stress-responsive genes. Genome editing using artificial nucleases such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENS), and Clustered Regulatory Interspaced Short Palindromic Repeat (CRISPR), CRISPR-associated protein 9 (Cas9), has significantly impacted basic as well as applied research including plant breeding by accelerating the editing of target genome in precise and predictable manner. Here, in this chapter, we are not going to discuss the past transgenic development approaches; mostly we will review some of the recent advancement made in the field of transgenic plants and the potential exploitation of genome-editing tools such as in conferring environmental stress tolerance in crops under field condition.