Drought Resistance by Engineering Plant Tissue-Specific Responses

Abstract

Drought is the primary cause of agricultural loss globally, and represents a major threat to food security. Currently, plant biotechnology stands as one of the most promising fields when it comes to developing crops that are able to produce high yields in water-limited conditions. From studies of Arabidopsis thaliana whole plants, the main response mechanisms to drought stress have been uncovered, and multiple drought resistance genes have already been engineered into crops. So far, most plants with enhanced drought resistance have displayed reduced crop yield, meaning that there is still a need to search for novel approaches that can uncouple drought resistance from plant growth. Our laboratory has recently shown that the receptors of brassinosteroid (BR) hormones use tissue-specific pathways to mediate different developmental responses during root growth. In Arabidopsis, we found that increasing BR receptors in the vascular plant tissues confers resistance to drought without penalizing growth, opening up an exceptional opportunity to investigate the mechanisms that confer drought resistance with cellular specificity in plants. In this review, we provide an overview of the most promising phenotypical drought traits that could be improved biotechnologically to obtain drought-tolerant cereals. In addition, we discuss how current genome editing technologies could help to identify and manipulate novel genes that might grant resistance to drought stress. In the upcoming years, we expect that sustainable solutions for enhancing crop production in water-limited environments will be identified through joint efforts.

Abscisic Acid and Flowering Regulation: Many Targets, Different Places

“…These advantages under drought conditions were highly situational [ 106 ]. Fast cycling, early flowering crops could avoid terminal drought and reduce the length of the crop season, but often this strategy pays a cost in terms of reduced yield [ 107 , 108 ]. It is still unclear what genetic adjustment may be needed to manipulate ABA sensitivity and flowering time.…”

Barley ABI5 (Abscisic Acid INSENSITIVE 5) Is Involved in Abscisic Acid-Dependent Drought Response

“…Abscisic acid (ABA) is the crucial regulator of plant responses to abiotic stresses. In the presence of unfavorable conditions, the precise regulation and function of ABA-dependent signaling components ensure the appropriate activity of stress-responsive genes (reviewed by Yoshida et al, 2019), and thus the regulation of physiological processes, such as photosynthesis, stomatal closure (Song et al, 2016;Cai et al, 2017;Saito and Uozumi, 2019), and osmoprotectant biosynthesis (Jones, 2016;Sah et al, 2016;Martignago et al, 2020).…”

Alternative Strategies for Multi-Stress Tolerance and Yield Improvement in Millets

“…Recently, CRISPR/Cas9 was used to improve heat tolerance by targeting the SlAGAMOUS-LIKE 6 (SIAGL6) gene, which showed enhanced fruiting ability under heat stress in tomato [ 190 ]. CRISPR/Cas9 was also used for drought tolerance in maize by regulating the ARGOS gene without affecting the yield of the crop [ 181 , 191 ]. CRISPR/Cas9 technology has tremendous potential in developing multi-stress-resilient crops via simultaneous expression of many structural and regulatory genes in crop plants.…”