摘要
采用室内培养方法,研究了土壤中不同浓度氯苯(CB)、1,2,4-三氯苯(TCB)和六氯苯(HCB)胁迫对蚕豆幼苗生长、超氧化物歧化酶(SOD,EC1.15.1.1)活性及丙二醛(MDA)含量变化的影响。结果表明,50～300μg·g-1TCB处理5d后蚕豆幼苗生长受到抑制(P<0.05和P<0.01)。50～300μg·g-1TCB胁迫1～5d对蚕豆幼苗SOD活性的影响表现出明显的剂量-效应关系。TCB处理5d后的幼苗恢复培养3d,50μg·g-1TCB处理组的SOD活性得到恢复,而100和300μg·g-1TCB处理组的SOD活性明显高于对照(P<0.05和P<0.01)。试验亦表明,100和300μg·g-1TCB处理3d和5d,幼苗MDA含量均比对照显著增加(P<0.05和P<0.01),并且与TCB浓度之间存在明显的正相关关系。上述结果表明,蚕豆幼苗SOD活性及MDA含量可作为短期土壤TCB污染的生物标记物,而50～1000μg·g-1CB或HCB处理5d对蚕豆幼苗没有产生明显的毒性效应。
Root growth, changes in superoxide dismutase (SOD, EC 1.15.1.1) activity, malonyldialdehyde (MDA) level of broadbean seedlings were evaluated at different concentrations of chloro- benzene (CB), 1,2,4- trichlorobenzene (TCB) and hexachloro- benzene (HCB) in a soil. The results showed that root growth of seedlings was interrupted after 5 d at concentrations of 50 ～ 300 μ g· g- 1 with TCB treatment. The effects of TCB stress on SOD activity in seedlings displayed significant dose- effect relationship during the period of 1～ 5 d at concentrations of 50～ 300 μ g· g- 1. When broadbean seedlings were released from 5 d of TCB stress to a clear tap- water for 3 d, SOD activity at 50 μ g· g- 1 TCB recovered to the control level (P >0.05) while a significant increase in SOD activity was observed at 100 and 300 μ g· g- 1 TCB, compared to control (P< 0.05 and P< 0.01, respectively). The experiments also revealed that a significant increase of MDA level in seedlings occurred after 3 d and 5 d of 100 and 300 μ g· g- 1 TCB treatment (P< 0.05 and P< 0.01), and there was a positive correlation between TCB concentrations and MDA levels. All the above results indicated that SOD activity and MDA level of broadbean seedlings may be proposed as biomarkers for short- term TCB contamination in soil. Compared to TCB, the toxicity of 50 ～ 1 000 μ g· g- 1 CB or HCB in soil to broadbean seedlings was not found after a 5 d exposure.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2004年第3期432-436,共5页
Journal of Agro-Environment Science
基金
国家自然科学基金(20277040
20377043
20337010
20225722)
沈阳生态实验站基金资助
关键词
土壤
氯苯类污染
蚕豆
SOD活性
生物标记物
soil
chloro- benzenes contamination
broadbean
SOD activity
Biomarkers
