Exogenous silicon application promotes growth and alleviates drought and salt stresses of rice plants

In the current study, the influence of silicon (Si) on KDML 105 rice plants exposed to drought and salt stress was observed. The 28-days old rice plants were arranged into control, drought, and salinity conditions. The drought and salinity conditions were achieved by addition of 20% W/W polyethylene glycol 6000 and 120 mM NaCl to the nutrient solution, respectively. Si was concurrently applied in all groups by adding 0, 1.5, 2.0, and 2.5 mM Na2SiO3. The results showed that some growth and physiological parameters were positively changed by the Si-application. The relative water content was significantly improved in the 1.5 mM Si-supplemented drought group and the 2.0 mM Si-supplemented salt group. Additionally, Si at 2.0 mM significantly improved photosynthetic activity in the rice and slightly reduced plant temperature under salt stress. Moreover, exogenous Si ameliorated NaCl toxicity from the sodium-potassium ratio decline. The results suggested that 2.0 mM silicon was a proper concentration to recover plants exposed to abiotic stress.