Transcriptome sequence reveal the roles of MaGME777 and MabHLH770 in drought tolerance in Musa acuminata.

Banana, a globally cultivated fruit, faces significant constraints in distribution and sustainable production due to drought stress. This study investigated drought tolerance in Cavendish bananas using RNA-seq time-course analysis and molecular biology experiments. Plants were subjected to dehydration treatments, and physiological indicators such as electrolyte leakage, proline content, malonaldehyde, peroxidase activity, and hydrogen peroxide content were assessed. RNA-Seq and qRT-PCR were used to analyze transcriptional changes under drought. Weighted gene co-expression network (WGCNA) analysis identified thousands of differentially expressed genes (DEGs) at different time points, with a core set of 2660 DEGs consistently identified. KEGG enrichment analysis revealed MaGME777, a glycolysis/gluconeogenesis gene, as a potential drought resistance regulator. Virus-mediated gene silencing (VIGS) of MaGME777 reduced drought tolerance in bananas. Yeast one-hybrid (Y1H) and luciferase reporter assays demonstrated that the transcription factor MabHLH770 directly binds and activates the MaGME777 promoter. VIGS downregulation of MabHLH770 also reduced drought tolerance. In conclusion, this study revealed that MabHLH770 is a positive regulator of drought stress, by targeting MaGME777 promoter and activating their expression to enhance drought tolerance. These findings provide a foundation for developing drought-resistant banana cultivars through molecular breeding approaches.