重金属Cd胁迫对红树蚬的抗氧化酶、消化酶活性和MDA含量的影响  

Effects of cadmium stress on the activities of antioxidant enzymes,digestive enzymes and the membrane lipid peroxidation of the mangrove mud clam Geloina coaxans (Gmelin)

作　　者：赖廷和[1] 何斌源[1,2] 范航清[1,2] 周如琼[3,1] 杨艳[3,1] 

机构地区：[1]广西科学院广西红树林研究中心,广西北海536007 [2]广西红树林保护重点实验室,广西北海536007 [3]广西大学林学院,广西南宁530000

出　　处：《生态学报》2011年第11期3044-3053,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金(4067050);广西北部湾基础研究重大专项(2010GXNSFE013002);广西科技攻关项目(桂科攻0895004-10992026-1)

摘　　要：在实验室条件下,观测不同Cd胁迫处理(时间和水平)对红树蚬(Geloina coaxans(Gmelin))的胃组织中超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性、丙二醛(MDA)含量,及淀粉酶、脂肪酶和蛋白酶等3种消化酶活性的影响效应。结果表明,高浓度组(4.00 mg/L和8.00 mg/L)在较短的暴露时间即出现SOD活性显著诱导,而低浓度组则需要更长的暴露时间。所有处理组的CAT活性均先受诱导而后抑制,但去除胁迫后低浓度组活性上升,高浓度组则持续下降。低浓度处理组在胁迫初期MDA含量上升,但随后下降至较低水平;高浓度处理组MDA含量上升稍为滞后,但随后上升至较高水平。在消化酶方面,Cd对红树蚬胃组织淀粉酶的影响基本上表现为抑制;在胁迫初期脂肪酶活性受到显著诱导,随着胁迫时间延长酶活性则下降,同时胁迫解除后不同程度恢复;对蛋白酶的影响效应规律性不明显。显著的效应-剂量间相关关系存在于特定时间的SOD活性(1d),CAT、淀粉酶活性和MDA含量(7d和恢复6d)。探讨了这些指标作为生物标记物应用于监测海洋重金属污染的可能性。e Due to the increasing discharge ol pollutants into mangrove wetlands m China, a trend ol heavy metal pollution has been becoming more and more widely and intensively. The mangrove mud clam Geloina coaxans （Gmelin, 1791 ） is a dominant maerobenthos of mangrove wetlands, and serves as common seafood in the South China coast. Owing to its wide distribution, large body size and high abundance, the mangrove mud clam would act as a potential indicator of marine heavy metal pollution. .In this study, the effects of Cd stresses （levelxexposure time） on the activities of superoxide dismutase （SOD）, eatalase （CAT）, amylase, lipase and proteinases and malondialdehyde （MDA） content in the stomach tissues of the mangrove mad clams were studied under hydrological culture. Eight Cd levels, i.e. 0, 0. 125, O. 25, O. 50, 1.00, 2.00, 4.00 and 8. O0 mg/L were chosen. The stomach tissues of the mangrove mud clams were sampled on 0 d （ the beginning day） , ld, 3d and 7d, and Cd-release 6d respectively. The results showed that the SOD activities in the stomach tissues of the mangrove mud clams were induced rapidly afterexposure to higher levels of Cd （4.00 mg/L and 8.00 mg/L） , while it needed longer time to induce the enzyme under lower Cd level. The CAT activities in all treatments were induced once exposure to Cd but inhibited with the prolonging of the exposure time. Stress-release experiments showed that these inhibition effects on the CAT activities could be reversed only under the lower levels of Cd exposure. MDA content increased once exposure to the low levels of Cd and then decreased with the prolonging of exposure time. However, under the high levels of Cd stresses, MDA contents increased with the exposure time and maintained at higher level even after the stress was released. Cd exposure had an inhibitory effect on the activities of the amylase. Significant induction of the lipase by Cd occurred at the early time of the exposure, especially under the lower levels of Cd treatments; however, t

关 键 词：红树林 红树蚬 CD胁迫 消化酶 抗氧化酶 脂质过氧化 

分 类 号：X174[环境科学与工程—环境科学]