Functional identification of maize transcription factor ZmMYB12 to enhance drought resistance and low phosphorus tolerance in plants.

Maize usually suffers from various abiotic stresses such as drought, high temperature, high salt, and deficiency of nutrient elements during growth and development period, which will eventually lead to the decline of yield and quality, resulting in serious agricultural yield reduction. MYB transcription factors are widely distributed in plants and involved in the whole process of plant growth and development and environmental response. Therefore, the screening and identification of MYB transcription factors conferring stress resistance can provide the theoretical basis and technical support for genetic improvement in maize. In this study, a R2R3-MYB family transcription factor gene, ZmMYB12, was cloned from maize materials under drought treatment. This gene showed inducible expression in response to drought, ABA, and PEG treatments. Maize plants with virus induced gene silencing (VIGS) of ZmMYB12 had higher sensitivity to drought and accumulated more reactive oxygen species (ROS), as well as smaller roots. The survival rate of ZmMYB12 silencing plants was lower after re-watering than the wild type plants (WT), indicating that ZmMYB12 was a positive regulator of drought response. Overexpression of ZmMYB12 in Arabidopsis thaliana resulted in less ROS accumulation and more lateral roots than WT, thus elevating drought resistance. After low phosphorus stress, ZmMYB12 overexpression Arabidopsis had more lateral roots and stronger root system, as well as higher contents of chlorophyll and anthocyanin. The content of inorganic phosphorus in ZmMYB12 overexpression Arabidopsis was also higher than WT. In conclusion, this study indicates that ZmMYB12 positively regulates drought response and increases the uptake and utilization of phosphorus in plants, providing an elite gene for maize breeding to increase abiotic resistance. [ABSTRACT FROM AUTHOR]