CAJ | 학술논문

通过水培试验,研究Cd2+胁迫对萝卜幼苗活性氧的产生、脂质过氧化和抗氧化酶活性的影响.超氧阴离子(O-2)的产生速率和丙二醛(MDA)的含量与对照相比有不同程度的增加,表明Cd2+胁迫能导致萝卜体内的氧化胁迫;超氧化物歧化酶(SOD)的活性,随着Cd2+浓度提高,首先明显上升,然后逐渐下降,甚至低于对照,叶片过氧化氢酶(CAT)的活性明显增加,根系CAT活性则减少,根系以及较高浓度Cd2+处理后期叶片谷胱甘肽还原酶(GR)的活性均显著增加.推测:胁迫初期可能主要由SOD和CAT发挥抗氧化作用;后期由于抗坏血酸-谷胱甘肽(AsA-GsH)循环途径的激活,以及还原型谷胱甘肽(GSH)和植物络合素(Phytochelatins,PCs)的合成,可能在清除活性氧或者直接鏊合Cd2+中起作用.
통과수배시험,연구Cd2+협박대라복유묘활성양적산생、지질과양화화항양화매활성적영향.초양음리자(O-2)적산생속솔화병이철(MDA)적함량여대조상비유불동정도적증가,표명Cd2+협박능도치라복체내적양화협박;초양화물기화매(SOD)적활성,수착Cd2+농도제고,수선명현상승,연후축점하강,심지저우대조,협편과양화경매(CAT)적활성명현증가,근계CAT활성칙감소,근계이급교고농도Cd2+처리후기협편곡광감태환원매(GR)적활성균현저증가.추측:협박초기가능주요유SOD화CAT발휘항양화작용;후기유우항배혈산-곡광감태(AsA-GsH)순배도경적격활,이급환원형곡광감태(GSH)화식물락합소(Phytochelatins,PCs)적합성,가능재청제활성양혹자직접오합Cd2+중기작용.
While seedlings of radish raised in increasing contents of Cd2+ in hydroponic system,increment in ratio of superoxide dismutase(SOD)/catalase(CAT)and levels of superoxide anion(O2)and lipid peroxides were observed;125 μmol/L Cd2+ treatment resulted in a gradual elevation in SOD activity; while at Cd2+ level of 250 and 500 μmol/L,SOD activity considerably increased at first,then declined to even lower than that of the control. CAT activity showed enhancement in leaves whereas decrease in roots. Cd2+ induced an obvious elevation in GR activity in both roots and leaves. A marked elevation in GR activity suggests that ascorbate-glutathione(AsA-GsH)cycle may be activated to scavenge AOS and the synthesis of reduced glutathione(GSH)may be stimulated for subsequent synthesis of phytochelatins(PCs)to chelate Cd2+ directly.