Sphingolipids, including sphingosine-l-phosphate （SIP）, have been shown to function as signaling mediators to regulate diverse aspects of plant growth, development, and stress response. In this study, we performed functional analysis of a rice （Oryza sativa） SlP lyase gene OsSPL1 in transgenic tobacco plants and explored its possible involvement in abiotic stress response. Overexpression of OsSPL1 in transgenic tobacco resulted in enhanced sensitivity to exogenous abscisic acid （ABA）, and decreased tolerance to salt and oxidative stress, when compared with the wild type. Furthermore, the expression levels of some selected stress-related genes in OsSPLl-overexpressing plants were reduced after application of salt or oxidative stress, indicating that the altered responsiveness of stress-related genes may be responsible for the reduced tolerance in OsSPLl.overexpressing tobacco plants under salt and oxidative stress. Our results suggest that rice OsSPL1 plays an important role in abiotic stress responses.
Huijuan ZhangJing ZhaiJibo MoDayong LiFengming Song
