Abiotic stresses,such as drought,lead to crop growth damage and a decrease in crop yields.Stomata control CO2 uptake and optimize water use efficiency,thereby playing crucial roles in abiotic stress tolerance.Sddt (Semi-dwarfism and drought tolerance),a previously unknown function gene which was found participated microRNA-mediated regulation of stomatal development via interaction with DCL1.The overexpression of Sddt inhibited DCL1 expression level,and decreased the production of miRNA824 which can de-repress AGL16,then allowing AGL16 to initiate stomatal differentiation and development.Constitutive overexpression of Sddt in Arabidopsis resulted in inhibition of growth,and present semi-dwarf phenotype.