A Potential ABA Analog to Increase Drought Tolerance in Arabidopsis thaliana

Abscisic acid (ABA) plays an important role in the response of plants to drought stress. However, the chemical structure of ABA is unstable, which severely limits its application in agricultural production. Here, we report the identification of a small molecule compound of tetrazolium as an ABA analog (named SLG1) through virtual screening. SLG1 inhibits the seedling growth and promotes drought resistance of Arabidopsis thaliana with higher stability. Yeast two-hybrid and PP2C inhibition assays show that SLG1 acts as a potent activator of multiple ABA receptors in A. thaliana. Results of molecular docking and molecular dynamics show that SLG1 mainly binds to PYL2 and PYL3 through its tetrazolium group and the combination is stable. Together, these results demonstrate that SLG1, as an ABA analogue, protects A. thaliana from drought stress. Moreover, the newly identified tetrazolium group of SLG1 that binds to ABA receptors can be used as a new option for structural modification of ABA analogs.