Simultaneous expression of abiotic stress-responsive genes: An approach to improve multiple stress tolerance in crops

Abstract

Survival and productivity of crop plants under different stress scenarios are critical for sustainable crop production. Crop improvement towards achieving higher yield potentials under multiple stresses requires targeted breeding of crop varieties that can withstand different levels of abiotic and biotic stresses and still produce a reliable yield. In addition to this, many candidate genes have been validated for studying their role in enhancing tolerance levels in crops. Transgenic development with targeted stress tolerance trait manipulation can be a viable approach for attaining multiple stress tolerance. By this method, multilevel stress tolerance can be achieved by either manipulating candidate regulatory genes which can govern the functionality of a range of downstream genes or by adopting multigene stacking approach to pyramid genes in a same genetic background. The careful selection of genes linked to specific traits is the key to achieve marginal increase in productivity under multiple stresses. Diverse genes associated with various cellular tolerance mechanisms act in a concerted manner to impart varying degrees of stress tolerance. It will be highly rewarding if we examine different pathway-linked genes active in the stress scenario under scrutiny. Targeted genetic manipulation to enhance cellular tolerance under stress will be more economically viable if we combine multiple trait regulatory genes by using modern biotechnological tools. The different strategies employed, advantages of simultaneous expression of trait regulatory genes and the resultant crop adaptive mechanisms that are emerging in the recent years are discussed in this chapter.