Overexpression of RSOsPR10, a root-specific rice PR10 gene, confers tolerance against drought stress in rice and drought and salt stresses in bentgrass

RSOsPR10 was originally identified as a rice root-specific pathogenesis-related protein whose production was induced by drought and salinity stresses, but not by low temperature or abscisic acid. Our previous studies revealed that RSOsPR10 expression is up-regulated by jasmonic acid, and strongly inhibited by salicylic acid. Immunohistochemical experiments indicated RSOsPR10 is expressed in the root cortical cells. In the present study, we generated RSOsPR10-overexpressing lines of rice and bentgrass to examine the physiological roles of RSOsPR10 in plants. RSOsPR10-overexpressing rice plants were highly tolerant against drought stress, but not against salinity. In contrast, RSOsPR10-overexpressing bentgrass plants were tolerant against drought and salinity stresses. There was little difference between transgenic and wild-type plants regarding phenotype or above-ground growth rates. However, the root mass of the transgenic rice and bentgrass plants was significantly greater than that of the wild-type plants. Therefore, RSOsPR10 is likely involved in mediating environmental stress tolerance through an increase in root growth and development.