Overexpression of OsEm1 encoding a group I LEA protein confers enhanced drought tolerance in rice

Drought is the greatest threat for crops, including rice. In an effort to identify rice genes responsible for drought tolerance, a drought-responsive gene OsEm1 encoding a group I LEA protein, was chosen for this study. OsEml was shown at vegetative stages to be responsive to various abiotic stresses, including drought, salt, cold and the hormone ABA. In this study, we generated OsEm1-overexpressing rice plants to explore the function of OsEml under drought conditions. Overexpression of OsEml increases ABA sensitivity and enhances osmotic tolerance in rice. Compared with wild type, the OsEml-overexpressing rice plants showed enhanced plant survival ratio at the vegetative stage; moreover, over expression of OsEml in rice increased the expression of other LEA genes, including RAB16A, RAB16C, RAB21, and LEA3, likely protecting organ integrity against harsh environments. Interestingly, the elevated level of OsEml had no different phenotype compared with wild type under normal condition. Our findings suggest that OsEm1 is a positive regulator of drought tolerance and is potentially promising for engineering drought tolerance in rice. (C) 2016 Elsevier Inc. All rights reserved.