Adverse environmental factors like salt stress, drought, and extreme temperatures, cause damage to plant growth, development, and crop yield. GRAS transcription factors (TFs) have numerous functions in biological processes. Some studies have reported that the GRAS protein family plays significant functions in plant growth and development under abiotic stresses. In this study, we demonstrated the functional characterization of a tomato SlGRAS10 gene under abiotic stresses such as salt stress and drought. Down-regulation of SlGRAS10 by RNA interference (RNAi) produced dwarf plants with smaller leaves, internode lengths, and enhanced flavonoid accumulation. We studied the effects of abiotic stresses on RNAi and wild-type (WT) plants. Moreover, SlGRAS10-RNAi plants were more tolerant to abiotic stresses (salt, drought, and Abscisic acid) than the WT plants. Down-regulation of SlGRAS10 significantly enhanced the expressions of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) to reduce the effects of reactive oxygen species (ROS) such as O2- and H2O2. Malondialdehyde (MDA) and proline contents were remarkably high in SlGRAS10-RNAi plants. Furthermore, the expression levels of chlorophyll biosynthesis, flavonoid biosynthesis, and stress-related genes were also enhanced under abiotic stress conditions. Collectively, our conclusions emphasized the significant function of SlGRAS10 as a stress tolerate transcription factor in a certain variety of abiotic stress tolerance by enhancing osmotic potential, flavonoid biosynthesis, and ROS scavenging system in the tomato plant.
Keywords: ROS scavenging system; SlGRAS10; abiotic stress; flavonoid; tolerance; tomato.