NaCl胁迫对黄连木电阻抗图谱和抗氧化酶活性的影响

NaCl Stress on Electrical Impedance Spectroscopy Parameters and Activities of Antioxidative Enzymes of Pistacia chinensis Bunge

以1年生黄连木幼苗为材料,研究了不同浓度NaCl胁迫下叶片电阻抗图谱参数和抗氧化酶(SOD,POD, APX和GR)活性的变化,分析电阻抗图谱参数与抗氧化酶活性间的相关性。结果表明:(1)随着NaCl胁迫时间的延长,超氧化物歧化酶(superoxide dismutase, SOD)活性呈逐渐升高的趋势,其中胁迫25 d时,随盐度的加重其活性达到最大值;过氧化物酶(peroxidase, POD)和谷胱甘肽还原酶(glutathione reductase, GR)活性随NaCl浓度的升高呈逐渐下降的变化;胁迫15 d时,随着NaCl浓度升高,抗坏血酸过氧化物酶(aseorbate peroxidase, APX)活性呈先升高再降低后升高的变化,20~25 d时APX活性逐渐下降,NaCl浓度达0.30%时,APX活性显著低于对照。(2)当NaCl浓度大于0.30%时,胞外电阻率re、弛豫时间τ和弛豫时间分布系数ψ均逐渐减小,胞内电阻率ri逐渐增大。(3)经相关性分析可知,胞内电阻率ri与APX活性呈显著负相关,与SOD活性呈显著正相关。因此,用电阻抗图谱参数可以表征黄连木受NaCl胁迫的程度,胞内电阻率为评价NaCl胁迫的最佳参数,这为探明黄连木盐适应机制及盐碱地地区园林绿化提供依据。

To explore the salt adapatt ion mechanism of Pistacia chinensis Bunge. The electrical impedance spectroscopy(EIS) parameters and activities of antioxidative enzymes(SOD, POD, APX and GR) in leaves under different periods of NaCl stress of Pistacia chinensis Bunge were measured. The validity of EIS parameters was testified by comparing the relation ship between these parameters and activities of antioxidative enzymes. The results showed that:(1) Superoxide dismutase(SOD) activity in leaves of Pistacia chinensis Bunge were generally increased with prolonging the NaCl stress time, and reached the maximum values with the increase of NaCl concentration when Pistacia chinensis Bunge were treated 25 d. Peroxidase(POD) and glutathione reductase(GR) activity showed decreasing with the increasing NaCl stress. With the increase of NaCl concentration in 15 d,the activity of aseorbate peroxidase(APX) increased firstly and then decreased, the activity of APX decreased in 20~25 d, and the concentration of NaCl reached 0.30%, the APX activity was significantly lower than that of the control.(2) When NaCl concentrations was high er than 0. 30 % extracellular resistance re, relaxation time τ and distribution coefficient of τ of leaves decreased gradually, intracellular resistance rithen increased gradually.(3) The correlation analysis showed that there were significant negative correlations between intracellular resistance and APX activity, and significant positive correlation between intracellular resistance and SOD activity.Therefore, EIS parameters could effectively reflect the extent of Pistacia chinensis Bunge stressed by NaCl.Intracellular resistance riwas the best parameter for evaluating the NaCl stress of leaves in Pistacia chinensis Bunge,the provides a basis for exploring the adaptation salt mechanism of Pistacia chinensis Bunge and landscaping in saline-alkali areas.