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Biology and Biotechnology of Environmental Stress Tolerance in Plants, Volume 3

et al., 2016; Yoon et al., 2017; Chung et al., 2018; Gao et al., 2018; Shim

et al., 2018; Wang et al., 2018; El-Esawi et al., 2019a, b; Esmaeili et al.,

2019; Tang et al., 2019; Waqas et al., 2019). Recently, few published articles

comprehensively reviewed TFs engineering in crop plants for abiotic stress

tolerance (Baillo et al., 2019; Khan et al., 2019; Kimotho et al., 2019; Waqas

et al., 2019; Javed et al., 2020; Ahmed et al., 2020; Hrmova & Hussain,

2021; Manna et al., 2021).

7.3.1 TRANSGENIC PLANTS OVEREXPRESSING TRANSCRIPTION

FACTORS

Comprehensive genome-wide analysis of several plant species has yielded a

plethora of TFs belonging to various families (Cominelli et al., 2010; Yadav

et al., 2011; Seo et al., 2012; Gao et al., 2017). Consequently, functional

analysis of these TFs via knockout/knockdown analysis and overexpression

of TFs in both model and crop plants have reported their roles in plants.

Overexpression of TFs activates the expression of several downstream genes

which control the multigenic traits such as tolerance to abiotic stresses (Seki

et al., 2007; Hussain et al., 2011a). DREB gene family is the best studies

TFs using overexpression approach in different plants such as rice, barley

tobacco, soybean, wheat, tomato, potato, peanut, oilseed rape for abiotic

stress tolerance (Kasuga et al., 1999, 2004; Pellegrineschi et al., 2004; Oh

et al., 2005, 2007; Bhatnagar-Mathur et al., 2004, 2006, 2009; Behnam et

al., 2006; Ito et al., 2006; Chen et al., 2007, 2008; Zhao et al., 2007; Cong

et al., 2008; Wang et al., 2008). Similarly, several other TFs such as, MYB,

WRKY, NAC, bZIP, AREB, ERF, and CBF have been utilized for developing

stress-tolerant crop plants (Tran et al., 2004; Villalobos et al., 2004; Fujita

et al., 2005; Furihata et al., 2006; Zhang et al., 2005, 2007; Dai et al., 2007;

Liao et al., 2008; Trujillo et al., 2008; Zhou et al., 2008; Qiu & Yu, 2009;

Yanez et al., 2009; Abdeen et al., 2010; Morran et al., 2010).

As mentioned above, DREB and other TFs are playing significant role

in the regulation of abiotic stress tolerance in plants. For example, it is

reported that overexpression of SNAC1 in rice showed higher seed setting

(22–34%) in field conditions compared to control plants under drought

stress. Transgenic rice plants provided high yield because plants demon­

strated good control on closing of stomata leading to less water loss and

good photosynthetic performance under stress. Similarly, Overexpression of

OsNAC6/SNAC2 and ONAC045 conferred broad abiotic stress tolerance