雌激素胁迫对萝卜种子萌芽和幼苗生长及其累积效应的影响

Effects of estrogen stress on seed germination,seedling growth and accumulation in radish

通过水培试验,研究了不同浓度17β-雌二醇(17β-E2)胁迫对萝卜种子萌芽、幼苗生长和抗氧化酶系统活性的影响,以及17β-E2在幼苗体内的积累。结果发现,萝卜种子的发芽势、发芽率和根长与17β-E2处理浓度呈负相关,在10μg/L浓度时17β-E2刺激萝卜种子的发芽势和根长明显增加,诱导幼苗体内抗氧化酶SOD、POD和CAT活性显著上升;但在50μg/L浓度的17β-E2胁迫下,SOD、CAT和POD活性受到明显抑制,MDA含量显著升高,幼苗抗氧化能力显著降低,膜质过氧化程度加剧;受17β-E2污染,萝卜幼苗体内17β-E2积累量随着处理浓度的升高而增加,其在根部累积量要大于地上部分,在转运过程中发生17β-E2代谢,产生具有低雌激素活性的雌酮。萝卜对17β-E2胁迫具有一定的抗性,在17β-E2污染土壤中种植萝卜存在潜在的食用安全风险。

The effects of different concentrations of 17β-estradiol （17β-E2） on seed germination, seedling growth, antioxidant enzyme system and 1713-E2 accumulation in radish （Raphanus sati＇vus） were investigated using water culture method. The results indicated that the germinating potentiality, germination rate and root elongation of radish presented the inverse correlation with 1713-E2 treatment. The germinating potentiality and root elongation of radish were obviously increased and activities of SOD, POD and CAT of radish were signifi- cantly enhanced by 17β-E2 at levels of 10 u/L. The 50ug/L 171β-E2 treatment inhibited the activities of SOD, POD and CAT and significantly stimulated an increase in the content of MDA. It made seedling oxidation re- sistance significantly decrease and finally resulted in aggravate of the lipid peroxidation. With rising treatment concentration, the content of 17β-E2 accumulated in seedlings was increased. The content of 17β-E2 in the root was larger than that in aerial part. In the transportation process, 17β-E2 was partly metabolized into the low active estrone in radish. The experiments revealed that radish showed a certain tolerance to 17β-E2 stress, so there was a potential food risk posed to mankind health for radish growing in estrogen-contaminated soils.