钙对大豆幼苗镍毒害的缓解效应及对抗氧化酶活性的影响

摘要

In order to explore the possible physiological mechanisms of ameliorating nickel toxicity by calcium, this paper used pot culture to study the amelioration of nickel toxicity on soybean seeding by external calcium and its effect on the activity of SOD, CAT, POD, APX in leaf tissue. The results showed that the growth of soybean seeding was inhibited significantly when added Ni2+ was more than 60 mg/kg. But the nickel toxicity symptom was ameliorated to different degrees as adding different amount of calcium, and the treatment of 200 mg/kg Ca + was better than 100 mg/kg Ca + . Compared with no nickel added, the activities of SOD, CAT and APX in leaf tissue decreased significantly in the treatment of 60 mg/kg Ni2+, but POD increased obviously. When Ca2 + was combined, the activity of SOD, CAT, POD, APX in leaf tissue was improved obviously and the treatment of 200 mg/kg Ca2+ increased greater than 100 mg/kg Ca2+. It was suggested that Ca2 + ameliorated the nickel toxicity symptom through improving the activities of antioxidase in leaf tissue and enhancing the scavenging activity of active oxygen. It was one of mechanisms of external calcium ameliorating nickel toxicity on soybean seedlings.%采用盆栽方法,研究了镍毒害条件下外源钙对大豆镍毒害的缓解效应以及对其叶片组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性的影响,以探讨钙缓解植物镍毒性的生理机制.研究结果表明:Ni2+60 mg/kg添加量对大豆幼苗生长表现出明显的抑制作用,但是当加入不同钙量后,大豆的镍毒害症状得到不同程度的缓解,Ca2+ 200 mg/kg处理的缓解作用好于Ca2+ 100 mg/kg.与不施镍处理相比,单施Ni2 60 mg/kg处理的大豆叶片组织SOD、CAT和APX活性明显下降,而POD活性明显上升.当配施Ca2以后,大豆叶片组织中SOD、CAT、POD和APX活性明显提高,且Ca2+ 200 mg/kg处理的上升程度比Ca2+ 100 mg/kg处理的大.因此,Ca2+是通过提高叶片组织抗氧化酶活性,增强活性氧清除能力,而使大豆的镍中毒症状得到缓解,这是Ca2+减轻大豆镍毒害的生理机制之一.