孔石莼和条斑紫菜对Cu(Ⅱ)胁迫的光合生理和抗逆响应研究

Photosynthetic and stress resistance responses in macroalgae Ulva pertusa and Neopyropia yezoensis exposed to Cu(Ⅱ)

Cu(Ⅱ)暴露诱导大型海藻抗逆性与适应。为探讨Cu(Ⅱ)胁迫对大型海藻光合生长性能和抗逆系统的影响,以孔石莼(Ulva pertusa)和条斑紫菜(Neopyropia yezoensis)为受试生物,分别设置0、1、2 mg/L的Cu(Ⅱ)胁迫,研究了Cu(Ⅱ)暴露下两种大型海藻的生长适应与抗逆反应。结果表明:Cu(Ⅱ)暴露胁迫下,孔石莼和条斑紫菜光合作用受到明显抑制,光合色素叶绿素a、类胡萝卜素在不同浓度暴露组中均呈现含量减少。在抗逆系统中,孔石莼体内丙二醛含量和内源性超氧化物歧化酶活性随Cu(Ⅱ)浓度增加而降低,而条斑紫菜体内丙二醛含量和内源性超氧化物歧化酶活性随Cu(Ⅱ)浓度增加而升高。不同种属的大型海藻对铜暴露的敏感度不同,但均对Cu(Ⅱ)胁迫环境产生一定响应。藻类抗逆响应存在差异可能与藻体细胞受到胁迫时产生自由基的多少以及抗氧化剂强弱有关。

Copper induces resistance and acclimation in marine macroalgae.To investigate the effects of Cu(Ⅱ)stress on photosynthetic growth performance and stress tolerance system of macroalgae.Two macroalgae,Ulva pertusa and Neopyropia yezoensis,were exposed to 0 mg/L,1 mg/L,and 2 mg/L of Cu(Ⅱ)to investigate the responses of photosynthetic and resistance performance.The results show that the photosynthesis of U.pertusa and N.yezoensis is obviously inhibited under Cu(Ⅱ)stress.In both exposure groups,the levels of photosynthetic pigments,chlorophyll a and carotenoid,decreased.The content of MDA and activity of SOD in U.pertusa decreased as Cu(Ⅱ)concentration increased,while the content of MDA and activity of SOD in N.yezoensis increased as Cu(Ⅱ)concentration increased.The sensitivity of different macroalgae species to copper stress varies.The reason could be related to the content of free radicals and/or antioxidants produced by algal cells under stress conditions.