Milestones achieved in response to drought stress through reverse genetic approaches

Abstract

Drought stress is the most important abiotic stress that constrains crop production and reduces yield drastically. The germplasm of most of the cultivated crops possesses numerous unknown drought stress tolerant genes. Moreover, there are many reports suggesting that the wild species of most of the modern cultivars have abiotic stress tolerant genes. Due to climate change and population booms, food security has become a global issue. To develop drought tolerant crop varieties knowledge of various genes involved in drought stress is required. Different reverse genetic approaches such as virus-induced gene silencing (VIGS), clustered regularly interspace short palindromic repeat (CRISPR), targeting induced local lesions in genomes (TILLING) and expressed sequence tags (ESTs) have been used extensively to study the functionality of different genes involved in response to drought stress. In this review, we described the contributions of different techniques of functional genomics in the study of drought tolerant genes.

The Liriodendron chinense MKK2 Gene Enhances Arabidopsis thaliana Salt Resistance

“…Soil salinity occurs widely throughout the environment, subsequently eliciting a plant response for survival. Generally, elevated levels of salt are encountered by individual roots, but it is likely that the whole plant will respond to salt stress because of the various signal transductions regulated by gene expression [10]. MKK cascades play an important role in transducing developmental and environmental signals into adaptive responses [20,40].…”

“…A typical MAPK cascade consists of at least three sequentially acting serine/threonine kinases; one MAP kinase kinase kinase (MAPKKK), one MAP kinase kinase (MAPKK), and finally, the MAP kinase (MAPK) itself, with each phosphorylating and thereby activating the next kinase in the cascade [10]. In 1986, Sturgll and Ray [11] first discovered a MAPK in animal cells.…”

TIP Aquaporins in Plants: Role in Abiotic Stress Tolerance

“…Aquaporins are thought to be responsive to the stress signalling pathways and are also thought to be involved in the stress-coping mechanisms such as altering the tissue hydraulic conductivity [79,80]. Drought and salinity are two major factors that significantly limit plant growth and productivity [81,82]. The huge yield losses caused by drought stress ranging 45-92 (%) have been reported in major field crops like maize (Zea mays L.), wheat (Triticum aestivum L.), rice (Oryza sativa L.), chickpea (Cicer arietinum L.), soybean (Glycine max L.), sunflower (Helianthus annuus L.) [83].…”

Recent Progress in Germplasm Evaluation and Gene Mapping to Enable Breeding of Drought-Tolerant Wheat

“…Kim et al (2018) also successfully established a CRISPR/Cas9 genome editing system in wheat protoplasts to edit the stress-responsive factor genes TaDREB2 and TaERF3. Since some essential regulatory genes that control the biosynthesis of metabolites associated with drought tolerance have been identified (Yang et al, 2010), the CRISPR/Cas9 gene editing technology could potentially be used to target such genes and traits in the future (Singh B. et al, 2018). In addition, CRISPR/Cas9 mediated base editing (Zong et al, 2017;Li C. et al, 2018) and prime editing (Anzalone et al, 2019) techniques could be potentially utilized in breeding for drought tolerant wheat in the future as alternatives to the standard CRISPR/Cas9 genome editing system.…”

“…(2018) also successfully established a CRISPR/Cas9 genome editing system in wheat protoplasts to edit the stress-responsive factor genes TaDREB2 and TaERF3. Since some essential regulatory genes that control the biosynthesis of metabolites associated with drought tolerance have been identified ( Yang et al., 2010 ), the CRISPR/Cas9 gene editing technology could potentially be used to target such genes and traits in the future ( Singh B. et al., 2018 ).…”