MeWRKY30, a cassava stress-responsive WRKY transcription factor, confers drought resistance to transgenic Arabidopsis

MeWRKY30 enhances drought tolerance by reducing ROS and MDA accumulation via the activation of stress-related transcription factors and ROS-scavenging genes. Cassava (Manihot esculenta Crantz), cultivated primarily in tropical regions, is susceptible to drought stress, which adversely affects its yield productivity. WRKY transcription factors play crucial roles in regulating drought responses; however, the specific molecular pathways in cassava remain to be characterized. Our previous transcriptomic analyses under drought stress identified MeWRKY30, the expression of which was upregulated by both drought and abscisic acid treatments. Comparative analysis revealed that Arabidopsis lines overexpressing MeWRKY30 exhibited enhanced drought tolerance, characterized by reduced malondialdehyde accumulation compared with wild-type controls, as well as delayed flowering and reproductive development. RNA sequencing (RNA-seq) identified 3,002 genes regulated by MeWRKY30, including AtNAC72, AtERF24, AtCAT2, and AtSPL9. Electrophoretic mobility shift assays (EMSAs) and dual-luciferase reporter assays confirmed that MeWRKY30 directly binds to W-box cis-elements in the AtERF24 promoter, thereby activating its transcription. These results suggest that MeWRKY30 is a positive regulator of drought tolerance in cassava and has potential applications in transgenic breeding programs.