Cu2+对文蛤红壳色选育系及自然群体抗氧化能力的影响

Cu²⁺作为海洋重金属污染的主要污染物之一,具有来源广、易残留、易食物链富集等特点,是海洋贝类养殖业潜在的生态危机和经济危机。为查明江苏文蛤自然群体及红壳色选育系对重金属Cu²⁺耐受能力,设置不同质量浓度Cu²⁺对文蛤红壳色选育系和自然群体进行胁迫试验,研究Cu²⁺对文蛤超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性以及Cu/Zn-SOD基因相对表达量的影响。试验结果显示:(1)在相同质量浓度Cu²⁺条件下,红壳色选育系与自然群体存活率差异不显著(P>0.05)。(2)随着Cu²⁺质量浓度增大,两组文蛤的超氧化物歧化酶和过氧化氢酶活性变化共同表现出相应质量浓度—效应关系,超氧化物歧化酶活性变化呈线性上升趋势,而过氧化氢酶活性变化呈先抑制后诱导的趋势,两种酶活性变化差异显著(P<0.05)。(3)Cu/Zn-SOD基因表达变化与超氧化物歧化酶活性变化一致,与Cu²⁺质量浓度呈正相关。(4)红壳色选育系响应Cu²⁺抗氧化性要优于自然群体。本试验结果将对文蛤抗逆性选育及新品种开发提供科学参考。

Effect of Cu2+ on Antioxidant Capacity of Red Shell Color Breeding Line and Natural Population of Hard Clam Meretrix meretrix

Cu²⁺as one of the main pollutants of heavy metal pollution in the ocean is characterized by wide source,easy residue,and easy enrichment of food chain,which constitutes a potential ecological crisis and economic crisis for the cultivation of marine shellfish.In order to understand the tolerance of natural populations Meretrix meretrix and red shell color breeding lines of hard cham to different concentrations of Cu²⁺,the effects of different concentrations of Cu²⁺on the activities of superoxide dismutase(SOD)and catalase(CAT)and the relative expression of Cu/Zn-SOD gene in hard clam were studied.The results showed:(1)at the same concentration of Cu²⁺,the survival rate of red shell color breeding line hard clam was found to be slightly higher than that of natural population,without significant difference(P>0.05).(2)The changes in SOD and CAT enzyme activities of hard clam under different concentrations of Cu²⁺showed the corresponding time effect relationship and concentration effect relationship,and the SOD enzyme activity of hard clam showed a linear upward trend,while CAT activity showed a first trend,with significant difference between red shell color breeding line and natural population(P<0.05).(3)The expression of Cu/Zn-SOD gene was consistent with the expression of SOD enzyme activity.With the linear expression of Cu²⁺concentration,the maximal relative expression of gene was observed at Cu²⁺concentration of 0.4 mg/L.(4)The antioxidant activity of red shell color breeding line hard clam was better than that of natural population.The purpose of this study is to lay a theoretical foundation for the selection of stress resistance and the development of new species of hard clam.