Identification of Wheat d -Cysteine Desulfhydrase (TaD-CDes) Required for Abscisic Acid Regulation of Seed Germination, Root Growth, and Stomatal Closure in Arabidopsis

Cysteine desulfhydrase (CDes) can catalyze the degradation of cysteine producing hydrogen sulfide. In this study, d -cysteine desulfhydrase from wheat (TaD-CDes) was cloned and overexpressed in Arabidopsis thaliana . The physiological effects of TaD-CDes were determined by investigating seed germination, root growth, stomatal closure, and drought resistance in the TaD-CDes plants. Results showed that, compared with wild-type plants (WT), seed germination, root growth, and stomatal closure of the TaD-CDes plants were more sensitive to ABA, resulting from up-regulation of ABA-responsive genes (such as PYR1, ABI1, ABI2, HAB1, HAB2, SnRK2, ABF2 , and ABF4 ). Moreover, although TaD-CDes mediated ABA-induced stomatal closure, TaD-CDes-overexpressing plants did not show higher drought resistance than WT, which might be attributed to their increased stomatal densities.