Effects of aniline on growth, oxidative and DNA damage of rice (Oryza sativa L.) seedlings

Abstract

Aniline is widely used in the fields of industry and agriculture. Aniline pollution is emerging as a serious global environmental problem, whereas the toxicity and the stress mechanism on higher plants is unclear. In order to clarify the mechanism of growth, oxidative and DNA damage caused by aniline in higher plants, we cultured two varieties of rice in different concentration of aniline solution. The results demonstrated that the germination rate, amylase activity and lipase activity were significantly inhibited during the germination period of rice when aniline concentration was ≥ 25 mg L −1 ( p < 0.05 or p < 0.01). Besides, aniline also significantly inhibited the growth of rice seedlings, especially the growth of root. In comparison with the control group, the length of rice root was reduced by 17.27%–76.26% (Mudanjiang 25) and 21.20%–77.36% (Yunxian 510). The accumulation trends of . O 2 − (superoxide anion), H 2 O 2 (hydrogen peroxide), and MDA (malondialdehyde) in the two rice were increased continuously, the antioxidant enzyme activity was first increased and then decreased. When the aniline concentration was higher than 50 mg L −1 , the enzyme activity decreased rapidly (especially for Yunxian 510). Furthermore, the DNA hyperchromicity effect increased first and then decreased, which indicated that low-concentrations aniline might induce DNA breakage and high-concentrations aniline might promote the occurrence of cross-linking of DNA chains. Aniline could reduce the DNA content of the two varieties of rice shoots and roots. Especially for Yunxian 510, the DNA content of leaves and roots respective was decreased by 69.37% and 81.19% when the aniline was 200 mg L −1 , which was significantly lower than that of Mudanjiang 25 ( p < 0.01). These results evidently demonstrate that aniline maintain serious growth, oxidative, and genetic toxic effects on rice, and the Yunxian 510 was more sensitive to aniline poisoning than that of Mudanjiang 25. • Aniline had a phytotoxic–genotoxic effect on the rice growth process. • Aniline significantly inhibited rice amylase and lipase activities at concentrations >10 mg L {-1} . • Aniline significantly inhibited rice germination and growth at concentrations >25 mg L {-1} . • Aniline above 50 mg L {-1} inhibited the activity of antioxidant enzymes, resulting in increased content of ROS in rice. • Aniline lead to an increase in the degree of DNA cross-linking and a decrease in DNA content in rice.