Physiological responses of marine Chlorella sp. exposed to environmental levels of triphenyltin.

Abstract

Triphenyltin (TPT) is a herbicide and antifouling agent that has been widely used. After TPT flows into water bodies, it will cause toxic effects on marine life. We evaluated the effect of environmental concentration level (0, 10, 100, and 200ng/L) on the cell density, antioxidant capability, and photosynthesis-related genes in the marine Chlorella sp. The results showed that 10 and 100ng/L TPT can promote the growth of marine Chlorella sp., 200ng/L TPT can inhibit the growth of marine Chlorella sp., and the TPT toxicity was accumulative. The chlorophyll composition changed. The content of chlorophyll a in 100ng/L and 200ng/L groups was significantly higher than that in the control group (p < 0.05) in 13days. The content of chlorophyll b in the 100ng/L and 200ng/L groups in 1day and 13days was significantly different from that in the control group (p < 0.05). The content of total chlorophyll in the 100ng/L and 200ng/L groups in 13days was higher than that in the control group (p < 0.05). The 200ng/L group began to suffer oxidative damage on the 12th day, and the pigment protein complex responded to oxidative damage through self-feedback regulation. On the 18th day, chld, cao, psy, rbcS, and rbcL genes were downregulated, and psbA gene was upregulated in the 10ng/L and 100ng/L groups, which may be a feedback regulation of self-oxidative damage. This paper analyzed toxicity of environmental levels of TPT to marine Chlorella sp., which provided new data support for the comprehensive evaluation of its marine ecological toxicity.