Transcription factor SlbHLH70 enhances drought tolerance in tomato

Abstract Drought stress profoundly impacts plant productivity worldwide. The roles of Basic helix–loop–helix (bHLH) transcription factors are critical in processes of plant growth, development, and stress management. However, roles of specific bHLH genes in tomato, particularly in relation to drought tolerance, remain poorly understood. This research identified SlbHLH70 as a factor that enhances drought tolerance in tomato. Transgenic lines overexpressing SlbHLH70 exhibited enhanced drought tolerance and improved post-stress recovery, whereas SlbHLH70 knockout mutants showed increased sensitivity to drought stress. Further study showed that SlbHLH70 directly regulated genes associated with abscisic acid (ABA) synthesis, ABA-mediated signal transduction, and root development. Our research identified SlbHLH70 as an important regulator of drought resistance in tomato, offering a valuable genetic target for enhancing crop resilience to water shortages.