Drought is a major abiotic stress that causes the yearly yield loss of maize,a crop cultured worldwide,thus breeding drought tolerant maize cultivars is a priority target of the world agriculture.Clade A PP2C phosphatases (PP2CA) are conserved in plants and are important for ABA signaling and plant drought response.However,the natural variations of PP2CA genes that directly associated with levels of drought tolerance remain to be elucidated.