The LBD transcription factor TaLBD16 positively regulates drought tolerance in wheat

Drought stress has a severe negative effect on the growth and development of wheat, thus greatly reducing its yield and quality. Lateral organ boundaries domain (LBD) proteins serving as plant-specific transcription factors can play vital roles in regulating plants growth and development along with plants tolerance to abiotic and biotic stress. However, the detailed molecular mechanism of LBD proteins in adjusting drought resistance in wheat is still unclear so far. In this work, TaLBD16 was strongly induced by the drought and abscisic acid (ABA) treatments. Overexpression of TaLBD16-D can increase drought resistance and enhanced sensitivity to ABA in wheat. Specifically, when compared with wild-type plants, TaLBD16-D overexpression lines displayed increased survival rates, antioxidant enzyme activities and photosynthetic activity, along with reduced leaf water loss rates, malondialdehyde levels, electrolyte leakage and reactive oxygen species content under the drought conditions. RNA-seq and RT-qPCR analyses further uncovered that TaLBD16-D exerts its function by activating stress-associated genes and ABA signaling genes. Yeast two-hybrid and luciferase complementation imaging assays as well as yeast expression system demonstrated that TaLBD16-D might interact with TaTBP1 to enhance drought tolerance in wheat. In conclusion, our findings highlight the role of TaLBD16 in drought tolerance and provide a potential favorable candidate gene for enhancing the ability of drought tolerance in wheat.