向日葵对锶的富集特征与耐受机制研究

发布时间：2018-03-26 06:40

  本文选题：向日葵　切入点：锶　出处：《环境科学学报》2017年12期

【摘要】：为探明向日葵(Helianthus annuus L.)对金属锶的富集特征和耐受机制,本试验施加不同浓度锶(25、150、750和1500 mg·kg-1)土培处理30 d,研究了向日葵幼苗体内锶的富集和分配特征及对植物生长和膜脂过氧化产物MDA(丙二醛)含量、SOD(超氧化物歧化酶)、POD(过氧化物酶)、CAT(过氧化氢酶)活性的影响.结果显示:(1)向日葵幼苗的根长、株高、根生物量和地上生物量随着土壤中金属锶浓度的升高呈先增加后降低的趋势;(2)向日葵的根、茎、叶均能富集金属锶,不同器官表现为根叶茎.向日葵的生物富集系数与不同器官金属锶富集浓度呈显著负相关,且根部金属锶浓度与富集系数的相关性最强;(3)MDA含量随着锶浓度升高呈先减少后增加的趋势,而抗氧化酶SOD、POD和CAT活性均随着锶浓度升高呈先增加后减少的趋势.SOD和POD活性在高浓度金属锶处理中受到了抑制,而高水平的CAT活性表明向日葵清除活性氧的能力增强.以上结果表明,向日葵的根、茎、叶均能积累锶,根部的富集能力最强,且根部的抗氧化酶系统对金属锶胁迫更为敏感,其中较高的CAT活性表明在向日葵耐受锶胁迫机制中起到关键作用.此研究为金属锶污染土壤的植物修复以及向日葵对锶的耐受机制提供理论依据.
[Abstract]:In order to study the enrichment characteristics and tolerance mechanism of strontium in helianthus annuus L., In this experiment, the enrichment and distribution of strontium in sunflower seedlings and the content of MDA-malondialdehyde (MDA) in plant growth and membrane lipid peroxidation were studied after 30 days of soil culture treatment with different concentrations of Sr 25150750 and 1500 mg kg-1. The superoxide dismutase (superoxide dismutase) and POD (superoxide dismutase) were used to study the effect of soil culture on plant growth and membrane lipid peroxidation. Effects of Oxidase CAT (catalase) activity. The results showed that the root length of sunflower seedlings, Plant height, root biomass and aboveground biomass increased first and then decreased with the increase of the concentration of strontium in soil. The bioconcentration coefficient of sunflower was negatively correlated with the concentration of strontium in different organs. The correlation between strontium concentration and enrichment coefficient was the strongest, and the MDA content decreased first and then increased with the increase of strontium concentration. The activities of SOD and CAT increased first and then decreased with the increase of strontium concentration. The activities of SOD and POD were inhibited by high concentration of strontium. The high level of CAT activity indicated that the ability of scavenging reactive oxygen species was enhanced. The results showed that the roots, stems and leaves of sunflower could accumulate strontium, the enrichment ability of roots was the strongest, and the antioxidant enzyme system of the roots was more sensitive to strontium stress. The higher activity of CAT indicates that it plays a key role in the tolerance mechanism of sunflower to strontium stress, which provides a theoretical basis for the phytoremediation of soil contaminated by strontium and the tolerance mechanism of sunflower to strontium.
【作者单位】： 河南科技大学农学院;中国科学院生态环境研究中心城市与区域生态国家重点实验室;河南科技大学食品与生物工程学院;
【基金】：河南科技大学青年基金项目(No.2014QN065);河南科技大学学科提升振兴A计划项目(No.13660001) 国家自然科学基金(No.U1304326)~~
【分类号】：X173;X591
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本文编号：1666781