Effect of silica ions and nano silica on rice plants under salinity stress

Silicon (Si) is an abundant macro-element in the soil that helps plants tolerate environmental stress conditions and can ameliorate soil conditions. In this work, we studied the effects of Si ions and silica nanoparticles (both extracted from rice straw) on the physiological and biochemical responses and the expression of the two silicon uptake genes LSi1 and LSi2 in rice under increasing NaCl salt concentrations (0, 100, 200, 400 and 800 mM). Results showed that silicon ions significantly attenuated the detrimental physiological and biochemical effects of NaCl on plants. This was due among other reasons to jasmonic acid (JA) signaling. Indeed, this phytohormone up-regulated the expression of the silicon uptake genes in salt-treated plants supplied with silica ions, activated their antioxidant defense systems and induced osmolyte production.