Seminars

Bananas (Musa spp.) are an important global fruit crop, but their growth and productivity are highly susceptible to drought stress. Although bananas employ complex adaptive responses to water deficit, the underlying morphological, biochemical, and molecular mechanisms remain poorly understood. This study investigated drought responses in banana by analysing morphological, biochemical, and molecular changes in well-watered, drought-stressed, and rewatered plants. Drought stress reduced leaf area, plant height, and stem circumference, while increasing antioxidant enzyme activities. To elucidate the molecular mechanisms underlying these responses, RNA sequencing was performed on leaf tissues. A total of 767 differentially expressed genes (DEGs) were identified in drought-stressed plants and 542 DEGs in rewatered plants relative to their respective well-watered controls. Among these, 81 DEGs encoded transcription factors, with the MYB family being the most highly represented. Transcriptomic responses indicated coordinated regulation of oxidative stress responses and cellular protection during drought adaptation. MaMYB86-like, a strongly drought-responsive MYB transcription factor, was subsequently selected for functional characterisation and ectopically expressed in yeast and Arabidopsis thaliana. Yeast cells expressing MaMYB86-like exhibited enhanced tolerance to both drought and heat stress, while transgenic Arabidopsis lines showed enhanced tolerance to drought stress. Collectively, these findings provide insights into the molecular mechanisms underlying drought adaptation in banana and identify MaMYB86-like as a potential candidate for developing banana plants with enhanced resilience to abiotic stress.