Abstract
PurposeThe present study was conducted to investigate the silicon (Si) induced modulations in the antioxidant response and yield formation of rice under high temperature conditions.MethodsFour rice genotypes i.e., wild-type flower 11 (WT), nitrate reductase gene interference material (NR-RNAi), nitric oxide synthase interference material (NO-RNAi), and nitric oxide synthase overexpression material (NO-OR) were applied with two Si fertilizer treatments i.e., Si0: 0 g/pot and Si12: 12 g/pot. All genotypes were grown in early season (April to July) with mean maximum temperature ranged from 29.32celcius to 36.13 celcius (higher than critical temperature range).ResultsCompared with Si0, the Si12 increased the grain number per panicle, effective panicle number, and seed setting rate as well as rice yield of all rice genotypes under high temperature conditions. The yields of NR- RNAi and NO-OR was increased by 95.11% and 103.40%, respectively in Si12 than Si0. Moreover, Si application also improved the dry biomass of all rice genotypes whereas the stem and leaf weight of WT and leaf weight of NO-OR was increased by 36.70%, 166.67% and 36.63%, respectively, in Si12 as compared with Si0. In addition, the Si12 increased the catalase (CAT) activity and decreased the malondialdehyde (MDA) contents, which markedly reflected in NO-RNAi CAT activity (67.10%) at heading stage and NO-RNAi MDA content (53.61%) at maturity stage.ConclusionsOverall, Si application tend to increase the rice yield, improved dry matter accumulation and enhanced the stress tolerance of rice under high temperature conditions.