【摘要】 本研究以龙葵为试验材料,采用水培方法分析了补充Fe对龙葵幼苗Zn毒害耐受性的影响。结果表明,补充200μmol.L 1Fe-EDTA提高了龙葵幼苗对Zn毒害的耐受性。400μmol.L 1ZnCl2处理导致龙葵幼苗株高、根长和叶绿素含量显著减少,并引起H2O2的积累。补充Fe后,植株生长状况得到明显改善,SOD、CAT和APX基因的表达和酶的活性显著提高。同时RT-PCR结果显示,补充Fe后,FeSOD2和CAT1基因的表达明显升高。这些结果表明,Zn毒害对龙葵幼苗生长发育的影响很大程度上可能是由于Zn毒害引起的缺Fe导致的;Zn毒害条件下补充Fe可以通过提高FeSOD2和CAT1基因的表达,提高抗氧化酶的活性,降低ROS的水平,降低植株的氧化伤害。本研究为进一步研究植物响应Zn毒害的生理分子机理,以及植物修复技术的实际应用提供了理论基础。更多还原

【Abstract】 The alleviating effects of iron(Fe) supplementation on zinc(Zn) toxicity were investigated in hydroponic Solanum nigrum seedlings.Hydroponic method was used to raise S.nigrum seedlings with three combined Zn and Fe concentrations — of 400 μmol.L 1 Zn,0 μmol.L 1 Fe,400 μmol.L 1 Zn + 200 μmol.L 1 Fe and standard 0.5 Hoagland nutrient solution as the control.The results showed that seedling height,root length and chlorophyll content reduced while H2O2 accumulation significantly increased in Zn-treated S.nigrum seedlings.Supplementation with Fe did not only improve Zn tolerance,but also increased gene expression and enzyme activities of SOD,CAT and APX in S.nigrum seedlings.RT-PCR results showed that supplementary Fe significantly increased FeSOD2 and CAT1 genes expressions.These results indicated that Zn toxicity-induced oxidation damage and growth inhibition were largely due to Zn-induced Fe deficiency in plants.Supplemental Fe in Zn-poisoned conditions improved FeSOD2 and CAT1 genes expressions.This enhanced antioxidant enzyme activity and reduced reactive oxygen species(ROS) level and oxidative damage of plants.The study provided the theoretical basis for further studies on molecular mechanisms of plant response to Zn toxicity and the practical applications for phytoremediation technology.更多还原