Overexpression of Camellia oleifera CoRVE1 enhances drought tolerance in transgenic Arabidopsis thaliana

Camellia oleifera is an important woody oil crop in China, whose growth and productivity are frequently limited by drought stress. Although transcription factors play crucial roles in plant stress responses, the functions of REVEILLE ( RVE ) family genes in C. oleifera remain largely unknown. In this study, we cloned the RVE1 homolog from C. oleifera , designated CoRVE1 , and investigated its role in drought tolerance. Expression analyses showed that CoRVE1 was significantly induced by drought, salt, and abscisic acid (ABA) treatments and displayed tissue-specific expression patterns. Heterologous overexpression in Arabidopsis thaliana revealed that Co RVE1 promoted plant growth and markedly enhanced drought tolerance: the survival rates of two overexpression lines reached 84% and 86%, markedly higher than that of wild-type plants (20%), and the detached-leaf water-loss rate after 200 min was reduced to 7.6% and 7.2%, compared with 9% in the wild type. Physiological analyses indicated enhanced antioxidant capacity, with increased activities of superoxide dismutase (SOD), peroxidase, and catalase (e.g.SOD activity increased by 84.6–85.7% in transgenic lines versus 37.6% in the wild type after 10 days of drought) and a 17–18% reduction in malondialdehyde accumulation under drought stress. In addition, transgenic lines showed improved osmotic adjustment, reflected by altered accumulation of proline, soluble sugars, and soluble proteins. Furthermore, several drought-responsive genes ( RD29A , RD22 , KIN1 , CO R15A/B , LEA14 , LEA76 , and CER3 ), as well as the ABA biosynthesis–related gene NCED3 , were significantly upregulated in CoRVE1 -overexpressing plants. These findings suggest that CoRVE1 positively contributes to drought tolerance by enhancing antioxidant defense and osmotic adjustment and is associated with the upregulation of stress-related genes. This study provides new insights into the drought response of C. oleifera and identifies CoRVE1 as a potential candidate gene for further functional study and genetic improvement of drought resistance in woody oil crops.