The Expression of CARK1 or RCAR11 Driven by Synthetic Promoters Increases Drought Tolerance in Arabidopsis thaliana

Abstract

Drought stress hinders plant growth and development, and abscisic acid (ABA) stimulates plants to respond to drought. Here, to increase plant tolerance to drought, we designed three synthetic promoters (Ap, Dp, ANDp) to determine transcription activity and drought stress resistance in plants resulting from combinations of (1) synthetic promoters and (2) the functional genes CARK1 (cytosolic ABA receptor kinase 1) and RCAR11 (regulatory components of ABA receptor 11). Transient expression of eGFP and the dual-luciferase assay demonstrated that the basal transcriptional activities of Ap and ANDp were present at low levels under normal conditions, while the synthetic promoters were apparently induced upon either treatment of exogenous ABA or co-transformation with effector DREB2A (dehydration-responsive element binding protein 2A). Analysis of the transgenic plants (Ap:CARK1, Dp:CARK1, ANDp:CARK1, and Dp:RCAR11-Ap:CARK1) showed that the synthetic promoters Ap, Dp, and ANDp increased the expression of exogenous genes in transgenic plants upon treatment of ABA or d-mannitol. ANDp:CARK1 and Dp:RCAR11-Ap:CARK1 transgenic plants were sensitive to ABA and d-mannitol during cotyledon greening and root growth. A drought tolerance assay revealed that ANDp:CARK1 and Dp:RCAR11-Ap:CARK1 exhibited a higher survival rate than others upon drought stress. These results indicate that the combinations ANDp:CARK1 and Dp:RCAR11-Ap:CARK1 can be used to generate drought stress resistance in plants.

HD2A and HD2C co-regulate drought stress response by modulating stomatal closure and root growth in Arabidopsis

“…For the drought stress tolerance assay, two-week old hd2 mutant or HD2-OE plants in drought-treated groups were withheld from watering for 11 and 13 days, respectively ( Ge et al., 2018 ). After the drought stress period, plants were rewatered for two days to allow them to recover.…”

Plant Synthetic Promoters: Advancement and Prospective

“…Wu et al reported that the spatial pattern of abscisic acid (ABA) mediated transcriptional regulation by evaluating an 'abscisic acid responsive element' (ABRE) in root tissues [80]. The interaction of the synthetic promoter in association with functional genes responsible for cytosolic ABA, receptor kinase 1 (CARK1), and regulatory components of ABA receptor 11 (RCAR11) lead to drought stress tolerance [81].…”

A Fruitful Decade Using Synthetic Promoters in the Improvement of Transgenic Plants

“…In particular, EKCM showed a 1.29-fold increase in GUS activity in different tissues of transgenic A. thaliana under dehydration conditions (Hou et al, 2012). Synthetic promoters Ap, Dp, and ANDp were also designed to provide drought resistance in plants (Ge et al, 2018). The combination of functional genes for cytosolic abscisic acid (ABA) receptor kinase 1 ( CARK1 ) and regulatory components of ABA receptor 11 ( RCAR11 ) with synthetic promoters resulted in drought stress tolerance.…”

“…The combination of functional genes for cytosolic abscisic acid (ABA) receptor kinase 1 ( CARK1 ) and regulatory components of ABA receptor 11 ( RCAR11 ) with synthetic promoters resulted in drought stress tolerance. It was also reported that exogenous ABA or co-transformation with the effector dehydration-responsive element binding protein 2A (DREB2A) induced the activity of the synthetic promoters (Ge et al, 2018). They concluded that a combination of synthetic promoters and functional genes ( Dp.RCAR11 - Ap.CARK1 and ANDp.CARK1 ) can be used to generate drought stress resistance in different plants.…”