PFOS对小油菜生长发育的毒性效应及机制

Toxic effects and mechanisms of PFOS on the growth of rape(Brassica campestris L.)

为探讨全氟辛烷磺酸(PFOS)对小油菜的毒性效应,采用室内盆栽种植的方法,研究了PFOS对小油菜发芽和生长发育的影响,并结合土壤酶活性变化探讨了其毒性机理。结果表明:PFOS暴露浓度与小油菜的发芽率和茎叶增长率表现为非单调剂量-效应关系。50 mg·kg^(-1)暴露时小油菜发芽和茎叶的增长率分别为9.24%(P=0.001)和47.97%(P<0.001);小油菜发芽和茎叶生长的抑制浓度分别为100 mg·kg^(-1)和250 mg·kg^(-1);随着暴露进一步增大,小油菜发芽和茎叶增长的抑制率无显著变化。土壤蔗糖酶和碱性蛋白酶活性在PFOS暴露下也表现为低浓度刺激表达、高浓度抑制表达效应,这与PFOS暴露下小油菜的生长规律具有一定的正相关性。因此,PFOS对小油菜的毒性不仅与其对小油菜的直接损伤有关,还与其对小油菜种植土壤肥力的影响有关。

To determine the toxic effects of perfluorooctane sulfonate （PFOS） on rape （Brassica campestris L.）, the effects and mechanisms of PFOS on rape germination and growth, combined with changes of soil enzyme activities were studied using potted plants. The results showed a non-monotonic dose-response relationship between PFOS exposure concentrations and rape germination rates and stem length. At 〈 50 mg·kg-1 PFOS concentrations, the germination rates and stem length increased by 9.24%（P=0.001 ） and 47.97% （P〈0.001）, respec- tively. Concentrations that inhibited rape germination and stem growth were 100 mg·kg-1 and 250 mg·kg-1 PFOS, respectively. However, with increased PFOS concentrations, rape germination and stem growth did not change significantly. Soil sucrose and alkaline protease activ- ities increased with low PFOS doses and were inhibited by high PFOS doses, and were positively correlated with rape growth. Therefore, PFOS toxicity directly affected rape germination and growth, and influenced the planting soil fertility.