The Ecological Toxicology Research Of Prochloraz And Its Degradation Products On Chironomid

Prochloraz is widely used in the agricultural production as an efficient and broad-spectrum fungicide. At present, prochloraz is the main pesticide to treat rice blast. However, prochloraz will gather into the water environment through the biosphere material circulation after its application, causing the pollution of the surface waterand underground water, which makes the underlying organisms in some food chains in low dose exposure of prochloraz for a long time, and chronic poisoning, harming the ecosystem.Chironomid is an aquatic insect in the worldwide, with a great variety and wide distribution range, and has an absolute advantage in the benthic biomass. Chironomid is the natural bait of fishes in water, and is very important in the aquatic food chain, due to its high nurtritional value. Furthermore, it is used as an important indicative organism in biological monitor of the water body in many countries of the world. Therefore, it is of great significance to study the toxicological effects of prochloraz and its degradation products 2,4, 6-trichlorophenol on non-targeted organism chironomid.This paper researched the impact of prochloraz and its degradation products 2,4, 6-trichlorophenol on non-targeted organism chironomid, paddy soil and sediment in the river. On the molecular level, the effects of prochloraz and 2,4,6-trichlorophenol on the Mn-SOD, Cu·Zn-SOD, POD, CAT gene expressions of chironomid larvae were measured by RT-PCR, the enzyme activities of SOD, POD and CAT were detected by ultraviolet spectrophotometer and Thermo Scientific Microplate Reader. In addition, the adsorption of prochloraz and 2,4,6-trichlorophenol in soil were detected by HPLC. Now the main research reported as follows:The adsorption equilibrium time of prochloraz in the soil was 5～10h, while the adsorption equilibrium time of 2,4,6-trichlorophenol was 3～10h. In the certain concentration range, before the adsorption of prochloraz reached the equilibrium, the adsorption quantity increased with the increase of time, while 2,4,6-trichlorophenol reached the maximum adsorption quantity and then decreaed gradually to the amount of adsorption equilibrium. The adsorption effect of prochloraz is influenced by the content of orgaine matter significantly.The results of RT-PCR were that prochloraz showed the activation role initially and then inhibition phenomenon on the Mn-SOD, Cu·Zn-SOD, POD, CAT genes of 4 age Chironomus riparius larvae. After treatment with prochloraz for 12h at 400μg/L, the up-regulated expression of Mn-SOD, Cu-Zn-SOD, POD and CAT were:1.13-,1.13-,1.08-and 0.78-fold. After treatment for 48h, the down-regulated expression of Mn-SOD, Cu·Zn-SOD, POD, CAT were:82%,80%,79%,39%. While 2,4,6-trichlorophenol exhibited the activation initially and then inhibition and finally activation phenomenon on the Mn-SOD, Cu·Zn-SOD, POD and CAT genes. After treatment with 2,4,6-trichlorophenol for 12h at 400μg/L, the up-regulated expression of Mn-SOD, Cu-Zn-SOD, POD, CAT were:1.08-,1.10-,1.04-1.11-fold. After treatment for 24h, the down-regulated expression of Mn-SOD, Cu·Zn-SOD, POD, CAT were 77%,61%,66%,67%. After treatment for 48h, the up-regulated expression of Mn-SOD, Cu·Zn-SOD, POD, and CAT were:1.36-,1.02-,0.99-and 1.77-fold.After measuring the activities of SOD, POD and CAT by ultraviolet spectrophotometer and Thermo Scientific Microplate Reader, It showed that the SOD, POD and CAT were activated after the 4 age Chironomus riparius larvaes were treated with prochloraz for 12h: SOD increase to 1.17-fold, POD increase to 1.19-fold; CAT increase to 1.16-fold. And their activities were inhibited after treated for 48h:SOD decrease 76%; POD decrease 86%; CAT decrease 81%. After the 4 age Chironomus riparius larvae was treated with 2,4, 6-trichlorophenol for 48h, the determination of enzyme activities showed that the activities of SOD, POS and CAT were activated:SOD increase to 1.12-fold; POD increase to 1.07-fold; CAT increase to 1.10-fold. The final activity conclusions of SOD, POS and CAT were in accord with the gene test conclusions, which suggested that prochloraz and its degradation products 2,4,6-trichlorophenol would disturb the antioxidant system of Chironomid riparius larvae.