Influence of silicon supplementation on the growth and tolerance to high temperature in Salvia splendens

In this study, effects of silicon (Si) on the growth and activities of major antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX), and protein profile under high temperature stress were investigated. Salvia splendens 'Vista Red' and 'Sizzler Red' were grown in a glasshouse and potassium silicate (0 or 100 mg center dot L-1) was supplemented hydroponically. Overall important growth parameters, chlorophyll content, and biomass were significantly increased by Si application. In both cultivars, more Si deposition occurred in the root, followed by leaf and flower. In both normal and high temperature conditions, supplemented Si increased the activity of SOD, APX, and GPX, while it decreased the CAT activity. In the SDS-PAGE protein profile, three bands responding differentially to the Si treatment were observed. Especially in 'Vista Red' treated with Si, a protein band, approximately 46 kDa, was expressed strongly under the temperature stress. Results of this experiment showed that Si not only promoted the growth of salvia, but also played a vital role against temperature stress.