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作 者 ：殷欣， 张海玲， 吴杨， 王晓彤， 王全伟

期 刊 ：核农学报 2016年 30卷 2期 页码：364-371

关键词：大豆；24-表油菜素内酯；Cd胁迫；抗氧化酶；氧化伤害；

Keywords:soybeans, 24-epibrassinolide, Cd stress, antioxidant enzymes, oxidative damage,

摘 要 ：为探讨外源EBR缓解大豆幼苗Cd毒害的机理,以大豆品种黑农48为试材,采用营养液水培法,以不同浓度(0.01、0.05、0.1、0.2、0.5mg· L^-1)的24-表油菜素内酯(24-epibrassinolide,EBR)处理10mg·L^-1Cd胁迫下的大豆幼苗,研究外源EBR对Cd胁迫下大豆幼苗株高及根系生长,过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)3种抗氧化酶活性,丙二醛(MDA)含量和叶绿素含量的影响。结果表明,Cd胁迫下,喷施0.01~0.1mg·L^-1EBR对大豆各项生长指标的影响较单独Cd胁迫差异不显著;在0.2~0.5mg·L^-1EBR范围内喷施0.5mg·L^-1 EBR明显提高大豆的株高、根长、地下鲜重、地下干重,较单独Cd胁迫分别提高了17.9%、9.5%、33.3%、38.1%。低浓度EBR(0.01mg·L^-1和0.05mg·L^-1)对3种抗氧化酶活性、叶绿素含量的提高作用及MDA含量的降低作用不显著;在0.1~0.5mg·L^-1范围内喷施0.5mg·L^-1EBR,Cd胁迫处理2d和8d后POD、CAT、APX活性及叶绿素含量较单独Cd处理升高42.6%和48.1%,20.2%和67.7%,97.3%和64.8%,29.7%和15.6%,MDA含量较单独Cd处理降低19.7%和27.8%。因此,0.1~0.5mg·L^-1EBR是较适宜的喷施浓度,0.5mg·L^-1EBR是最佳的喷施浓度。适宜浓度的外源EBR能促进Cd胁迫下大豆的生长,提高其抗氧化酶活性,减轻膜脂过氧化的程度和光合系统的损伤,有利于增强植株耐Cd胁迫能力。本研究为阐明EBR缓解Cd胁迫对大豆幼苗伤害的作用机理提供理论依据。

Abstract:To explore exogenous EBR‘s relief of soybean seedlings Cd poisoning mechanism, soybean variety Hei Nong 48 was employed as the test material and treated under nutrient solution culture with different concentrations (0.01,0.05,0.1,0.2,0.5mg·L^-1 ) 24-epibrassinolide (24-epibrassinolide, EBR) process soybean seedlings under 10mg·L^-1 Cd stress, to investigate the effects of exogenous EBR on the height and root growth, peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX) three kinds of antioxidant enzyme activities, malondialdehyde (MDA) content, chlorophyll content of soybean seedlings under Cd stress. The results showed that under Cd stress, not significant difference was observed between spraying 0.01 to 0.1mg·L^-1EBR on soybean growth index and the Cd stress alone , while the treatment with high concentrations of EBR spraying 0.2 to 0.5mg·L^-1 the optimum concentration range EBR could significantly increase plant height, root length, fresh weight underground, underground dry weight, compared with Cd stress alone increased by 17.9%, 17.2 %, 33.3% and 38.1%, respectively. Low concentration EBR (0.01 and 0.05mg·L^-1) did not significantly improve three kinds of antioxidant enzyme activities and chlorophyll content or decrease MDA content not, in (0.1 to 0.5mg·L^-1) spraying the optimum concentration range EBR, after treatments of 2d and 8d stress make POD, CAT, APX activities and chlorophyll content than Cd treatment alone increased 42.6% and 48.1%, 33.4% and 67.7%, 116.8% and 64.8%, 29.7% and 39.1% , while MDA concentration decreased by 19.7% and 27.8% than the individual Cd treatment. Thus, 0.1 to 0.5mg·L^-1EBR was more appropriate spraying concentration, and the 0.5mg·L^-1EBR was the optimal spray concentration. Appropriate concentration of exogenous EBR could promote the growth of soybean under Cd stress, improve the antioxidant enzyme activities, reduce the degree of membrane lipid peroxidation and photosynthetic system damage, was conducive to enhancing the capacity of plant resistance to Cd stress. This study to elucidate the role of EBR relieving the injury of soybean seedlings under Cd mechanism provides the theoretical basis.

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