芘对苦草的生物毒性效应

Bio-toxic effect of pyrene on Vallisneria spiralis

通过静态模拟实验,研究了不同浓度(0.01、0.02、0.05、0.07和0.1mg·L-1)芘暴露10d后,芘在苦草中的富集,以及芘对苦草茎叶中自由基含量、抗氧化系统以及叶绿素、可溶性糖等的影响.结果表明:芘能够大量富集在苦草叶部;自由基信号强度、过氧化物酶(POD)活性和脂质过氧化产物丙二醛(MDA)含量持续升高;当污染加重时,这种升高现象有减弱的趋势,且三者有较好的相关性;谷胱甘肽S转移酶(GST)活性和氧化型谷胱甘肽(GSSG)含量持续增加,而还原型谷胱甘肽(GSH)含量持续降低;随着芘浓度的增加,叶绿素含量降低,而可溶性糖含量升高.苦草对芘暴露比较敏感,0.01mg·L-1即已显示胁迫效应.

With indoor static simulation test, this paper studied the effects of different concentrations （0. 01, 0. 02, 0. 05, 0. 07 and 0. 1 mg · L^-1 ） pyrene on the pyrene accumulation, free radical, antioxidant defenses, and the contents of chlorophyll and soluble sugar in Vallisneria spiralis. The results showed that after 10 clays exposure to pyrene, V. spiralis leaf could accumulate large amount of pyrene. The free radical generation, peroxidase （POD） activity and malondialdehyde （MDA） content had a persistent increase, but the increment decreased when exposed to higher concentrations （ 〉0. 05 mg· L^-1） pyrene. Glutathione S-transferase （GST） activity and oxidized glutathione （GSSG） and soluble sugar contents increased with increasing concentration of pyrene, while reduced glutathione （GSH） and chlorophyll contents were in adverse. It was concluded that V. spiralis tvas sensitive to pyrene, and the stress effect would happen at 0. 01 mg · L^-1 of pyrene.