Exogenous silicon (Si) increases antioxidant enzyme activity and reduces lipid peroxidation in roots of salt-stressed barley (Hordeum vulgare L.)
Exogenous silicon (Si) increases antioxidant enzyme activity and reduces lipid peroxidation in roots of salt-stressed barley (Hordeum vulgare L.)
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DOI：
10.1078/0176-1617-01065
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发表时间：
2003-10-01
影响因子：
4.3
通讯作者：
Ding, RX
中科院分区：
文献类型：
--
作者：
Liang, YC;Chen, Q;Ding, RX
两种不同类型的大麦(Hordeum visgare L.)以盐敏感品种科平7号和耐盐品种建4号为试材，研究了外源硅(Si)对盐胁迫下根系主要抗氧化酶活性和膜脂过氧化作用的影响。酶包括：超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)。3个重复的3个处理包括对照(不添加基础养分，不添加氯化钠和硅)、120mmo1/L-1nacl和120 mmo1/L-1nacl+1.0 mmo1/L-1sI。分别于处理后2、4、6d采集植物根，测定抗氧化酶活性、还原型谷胱甘肽(GSH)、丙二醛(MDA)含量和电解质渗漏率(ELP)。根中的超氧化物歧化酶、过氧化物酶和过氧化氢酶活性在盐胁迫第2天显著高于对照，但在第4天及以后显著下降，GR活性在第2天没有变化，但在第4天及以后显著下降。然而，与缺硅盐处理相比，外源硅显著提高了盐胁迫植物根系中这些酶的活性。这种硅效应是时间依赖的，并随着实验的继续而变得更强。抗氧化酶活性和GSH浓度的变化趋势与脂质过氧化终产物丙二醛和ELP的浓度变化趋势一致。与科品7号相比，建4号抗氧化酶活性较高，GSH含量较高，而丙二醛含量较低，ELP较低，这表明与建4号相比，建4号较不容易受胁迫依赖的膜脂过氧化影响。从大麦细胞膜的完整性、稳定性和功能等方面讨论了硅增强大麦耐盐性的影响。
Two contrasting barley (Hordeum vulgare L.) cultivars, i.e. Kepin No. 7 (salt sensitive) and Jian 4 (salt tolerant), were grown hydroponically to study the effect of exogenous silicon (Si) on time dependent changes of the activities of major antioxicant enzymes and of lipid peroxidation in roots under salt stress. Enzymes included: superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and glutathione reductase (GR). Three treatments with three replicates were investigated consisting of a control (basal nutrients with neither NaCl nor Si added), 120 mmol/L-1 NaCl, and 120 mmol/L-1 NaCl +1.0 mmol/ L-1 Si. Plant roots were harvested 2, 4 and 6 days after treatment and assayed for activities of the antioxidant enzymes and the concentrations of reduced glutathione (GSH) and malondialdehyde (MDA), and electrolytic leakage percentage (ELP). The activities of SOD, POD and CAT in roots of salt-stressed plants were significantly stimulated at Day 2 compared to control plants, but considerably decreased at Day 4 and onward, GR activity in roots of salt-stressed plants remained unchanged at Day 2, but significantly decreased at Day 4 and onward. However, exogenous Si significantly enhanced these enzyme activities in roots of salt-stressed plants compared to Si-deprived salt treatments. This Si effect was time-dependent and became stronger as the experiments continued. The tendency of change in the activities of antioxidant enzymes and the concentration of GSH coincided with the concentration of MDA, the end product of lipid peroxidation, and the ELP. Higher activities of antioxidant enzymes, and higher concentration of GSH, but lower concentration of MDA and lower ELP were noted in cultivar Jian 4 compared to Kepin No. 7, implying genotypic differences with Jian 4 being less susceptible to stress-dependent membrane lipid peroxidation. The effects of Si-enhanced salt tolerance are discussed with respect to cell membrane integrity, stability and function in barley.