Evaluating the effect of zinc oxide nanoparticles on the physiological responses of nine non-photoperiod sensitive rice cultivars

Abstract

The effects of nanopaticles on plant growth and metabolites have been reported in previous studies, but knowledge of the potential impacts of physiological responses is still unclear. Therefore, this study focused on the effect of exposure of zinc oxide (ZnO) nanoparticles on photosynthetic pigment contents (chlorophyll A, chlorophyll B and carotenoids) and the antioxidant enzyme activities (catalase and peroxidase) in nine non-photoperiod sensitive rice cultivars consisting of RD41, RD49, Chai Nat 1, Suphan Buri 1, Suphan Buri 2, Suphan Buri 3, Pathum Thani 1, Pathum Thani 80 and Phitsanulok 2. Rice plants were treated with 200 mg L-1 ZnO nanoparticles for every 15 days-interval. Rice plants were collected at 37, 44 and 51 days after planting for the evaluation of ZnO nanoparticles toxicity. The results showed that nine non-photoperiod sensitive rice cultivars treated with ZnO nanoparticle, as determined by the reduction of photosynthetic pigment contents. The activities of antioxidant enzymes protected plant cell when exposed to the toxicity of ZnO nanoparticles. This study showed that the supplementation of ZnO nanoparticles was no significant difference in photosynthetic pigment contents of rice cultivars. The results indicated that the accumulation of antioxidant enzyme activities could be protecting damage of the photosynthetic pigments in plant cells.