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Towards Engineering Smart Transcription Factors for Enhanced Abiotic Stress

(2007) reported the development of drought tolerant wheat variety, Ripper.

This variety has the potential to perform well under drought conditions with

high yield and other desirable characteristics. Considering both biotic and

abiotic stresses in variety development has far-reaching consequences. Stress

tolerant maize development programs reported a number of maize lines with

high productivity under various biotic and abiotic (drought) stresses (Badu-

Apraku & Yallou, 2009).

Generation and availability of molecular tools, especially phenotypic,

physiological, biochemical, and genetic markers, and molecular markers

(specific gene or QTL associated markers) have contributed immensely

towards the improvement of crop plants under abiotic stresses (Vinocur &

Altman, 2005). Similarly, molecular markers have the potential to identify

candidate genes with superior allelic variations in the breeding populations

(Tahmasebi et al., 2017). Merchuk-Ovnat et al. (2016) used QTLs introgres­

sion between wild emmer wheat and commercial wheat. This breeding-based

scheme improved drought tolerance in commercial tetraploid and hexaploidy

wheat. Similarly, recombinant inbred wheat population has been used for

QTLs mapping for combined heat and drought stresses. This strategy has

also demonstrated improved drought and heat individually or combination

of both stresses (Tahmasebi et al., 2017).

Emerging high throughput technologies offer an alternative to classical

breeding to identify and study specific loci with significant role in plant

tolerance (Lamaoui et al., 2018). Recently, genomic tools along with DNA

sequencing techniques and bioinformatics programs have revolutionized

plant biotechnological research. Similarly, genetic engineering tools can also

use to modify a biological function in transgenic plants (Hussain et al., 2012;

Zandalinas et al., 2017). Therefore, genetic engineering schemes could help

to manipulate desirable tolerance traits into crop plants (Hussain et al., 2012;

Zandalinas et al., 2017). Over the past decade, several studies used genetic

engineering as a tool for developing plants with enhanced abiotic stress

tolerance and successfully achieved significantly improved abiotic stress

tolerance in crop plants (Hussain et al., 2011b, 2012; Alvarez-Gerding et al.,

2015; Nuccio et al., 2015; Corrales et al., 2017).

7.1.2 GENETIC ENGINEERING FOR ENHANCED ABIOTIC STRESS

TOLERANCE

A plethora of research has contributed to our understanding of main steps of

gene expression, transcriptional regulation, and signal transduction in plant