Cd~(2+)胁迫对小桐子幼苗叶片抗氧化系统的影响

以小桐子幼苗为材料,设置不同浓度CdCl_2处理,测定Cd~(2+)胁迫对小桐子幼苗叶片中可溶性蛋白、丙二醛(MDA)含量,以及5种抗氧化酶活性和2种抗氧化剂含量的变化,探讨镉胁迫对小桐子幼苗抗氧化系统的影响。结果表明:(1)Cd~(2+)胁迫导致小桐子幼苗叶片中可溶性蛋白含量降低、MDA含量增加;(2)随着镉胁迫时间的延长,幼苗叶片中愈创木酚过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、抗坏血酸专一性过氧化酶(APX)、谷胱甘肽还原酶(GR)等抗氧化酶活性表现出先升高然后降低的变化趋势;(3)幼苗叶片中还原型抗坏血酸(ASA)和还原型谷胱甘肽(GSH)含量随着胁迫时间延长而降低,但其中氧化型抗坏血酸(DHA)和氧化型谷胱甘肽(GSSG)含量则升高。研究表明,镉胁迫初期能诱导小桐子幼苗抗氧化系统活性显著增强,提高其抗氧化能力,但随着胁迫时间的延长,致使其抗氧化酶的活性和抗氧物质含量下降,植株遭受明显氧化胁迫,幼苗生长受到镉的严重毒害。

Effect of Cd2+ Stress on Antioxidant System in the Leaves of Jatropha curcas Seedlings

Different concentrations of CdCl₂ were used to study the influence of cadmium stress on antioxidant system of Jatropha curcas seedlings.Results indicated that:1)the contents of soluble protein decreased,MDA increased.2)The activities of guaiacol peroxidase (POD),catalase (CAT),superoxide dismutase (SOD) and ascorbate specific peroxidase (APX),glutathione reductase (GR) firstly increased and then decreased.3)The antioxidants contents of ascorbic acid (ASA) and glutathione (GSH) decreased;contents of oxidized ascorbic acid (DHA) and oxidized glutathione (GSSG) increased in leaves of J.curcas seedlings under Cd²⁺ stress.The results showed that Cd²⁺ stress induced the abilities of antioxidative system increase,while the abilities were decreased and the seedlings were harmed after the prolonged treatments.