The NADPH-oxidase AtRbohl plays a positive role in drought-stress response in Arabidopsis thaliana

As the major resource of reactive oxygen species (ROS), the NADPH oxidases (Rbohs) have been shown to play important roles in plant cells under normal growth and stress conditions. Although many family members of Rbohs were studied, little is known about the function of Rbohl in Arabidopsis thaliana. Here, we report that exogenous ABA application decreases Rbohl expression and mannitol significantly increases Rbohl expression at transcript level. The Rbohl transcripts were strongly detected in dry seeds and roots. The loss-of-function mutant rbohl exhibited sensitivity to ABA and mannitol stress during germination. Furthermore, the lateral root growth of rbohl was severely inhibited after treatment with mannitol stress. Overexpression of Rbohl in Arabidopsis significantly improves the drought tolerance. Moreover, more H2O2 accumulated in Rbohl overexpressors than in wild type plants in response to mannitol stress. Our conclusion is that AtRbohl functions in drought-stress response in Arabidopsis thaliana. (C) 2017 Published by Elsevier Inc.