Regulation of Growth, Antioxidants and Sugar Metabolism in Rice (<i>Oryza sativa</i> L.) Seedlings by NaCl and Its Reversal by Silicon

Abstract

The effect of NaCl with or without silicon on the growth and metabolism in rice seedlings cv. MTU1010 was studied. In these seedlings, the oxidative stress has been observed with NaCl treatments and the levels of proline, H 2 O 2 and malondialdehyde contents were increased whereas catalase activity was decreased. NaCl exposure at 25 mM, 50 mM and 100 mM concentrations in the test seedlings resulted in an increase in both reducing and non-reducing sugar content. There was a decrease in starch contents and the activity of starch phosphorylase was increased. NaCl stress also affected the activities of different carbohydrate metabolizing enzymes. The activities of sucrose synthase and sucrose phosphate synthase were increased, while the activity of acid invertase was decreased. Joint application of silicon with NaCl showed significant alterations on all parameters tested under the purview of NaCl treatment alone leading to better growth and metabolism in rice seedlings. Thus the use of silicon enriched fertilizers may help to grow healthy rice plants in NaCl rich soil.