铝胁迫对黑大豆膜脂过氧化及抗氧化酶活性的影响

以耐酸型黑大豆(丹波黑大豆,简称RB)和酸敏感型黑大豆(简称SB)为材料,在水培条件下分析不同浓度的铝胁迫对这两种黑大豆叶和根膜脂过氧化和抗氧化酶活性的影响。结果显示:RB的铝耐受能力比SB强;在不同浓度铝胁迫下RB叶和根中的H2O2和MDA上升幅度低于SB,SB的叶和根中膜脂过氧化程度大于RB。在不同浓度铝胁迫下,RB叶和根中的SOD活性与SB差异不大,而CAT活性在RB和SB的叶和根中均被诱导显著升高,POD活性在RB叶和根中有下降趋势但仍然显著高于SB。因此,与酸敏感型的黑大豆相比,耐酸型黑大豆在铝胁迫下具有较强的保护酶活性,使其膜脂受氧化损伤的程度较低,从而表现出更强的耐铝胁迫能力。

Effects of Aluminum Stress on Membrane Lipid Peroxidation and Antioxidant Enzyme Activities in Black Soybean

Effects of Al stress on membrane lipid peroxidation and antioxidant enzyme activities of black soybean for acid-resistant type (Glycine max Tamba,referred to RB) and acid-sensitive type (referred to SB) were investigated under hydroponic conditions in this study.The results showed that RB was more resistant to Al stress than that of SB.H₂O₂ and malondialdehyde contents in SB leaves and roots were elevated more obviously than those in RB leaves and roots under Al stress,indicating that membrane lipid peroxidation in SB was greater than that in RB.Enzyme activity measurement suggested no significant difference was observed in leaf and root SOD activity between RB and SB under Al stress.However,leaf and root CAT activity were all induced and elevated markedly after RB and SB were treated with different concentration of Al.Moreover,leaf and root POD activity in RB displayed a descending trend but were still higher significantly than those in SB under Al stress.As compared with SB,RB possesses a stronger antioxidant enzyme system which confers on it a higher ability to scavenge ROS under Al stress.Thus,Al-induced lipid peroxidation was weaker in RB than that in SB.The data suggested that antioxidant enzyme system plays an important role in the Al-resistance mechanism of RB.