Effect of silicon on chilling-induced changes of solutes, antioxidants, and membrane stability in seashore paspalum turfgrass
We present a detailed study to investigate if silicon supplementation enhances chilling resistance of seashore paspalum (Paspalum vaginatum Swartz) turf. An enhanced growth status suggests an improved chilling resistance by Si addition, which is coupled with the observation of more Si cells in leaf epidermal cells, as well as a lower LT50 (the low temperature required to cause 50% electrolyte leakage). Chilling stress induces significant adaptive increases of free proline (P < 0.01), all soluble sugar (P < 0.01) and the activity of peroxidase (POD) (P < 0.05), and leads to the decreases of the activities of superoxide dismutase (SOD) and catalase (CAT) (P < 0.05), results in notably higher measurements of malondialdehyde (MDA) (P < 0.05). Silicon addition promoted significant increase of proline and sucrose (P < 0.01), while maintaining significantly higher activities of SOD, POD, CAT, and notably leveling off of MDA (P < 0.05) under chilling stress. These results indicate that silicon enhances the chilling resistance of turfgrass via maintaining a stable membrane and a beneficial cell status readily coping with the chilling-induced oxidative stress.