摘要
菠菜（ＳｐｉｎａｃｉａｏｌｅｒａｃｅａＭｉｌ．）品种“华菠一号”生长在室内条件下，以０．０和１３．０ｋＪ·ｍ－２·ｄ－１的ＵＶＢ进行照射处理，研究了ＵＶＢ对菠菜叶片内类黄酮和脂质过氧化作用的影响。结果表明：ＵＶＢ辐射降低了菠菜的单株叶鲜重，诱导了体内吸收ＵＶＢ的类黄酮化合物的大量积累，并使可溶性蛋白含量与叶绿素含量下降。ＵＶＢ辐射能使菠菜叶片内Ｏ－·２及丙二醛（ＭＤＡ）含量大幅度上升，而使抗坏血酸（ＡｓＡ）含量下降。ＵＶＢ辐射能使菠菜叶片内过氧化物酶（ＰＯＸ）、ＳＯＤ的活性大幅度上升，而过氧化氢酶（ＣＡＴ）活性仅略有增加。初步推测：ＵＶＢ辐射首先诱导菠菜叶片内Ｏ－·２的积累，并导致膜脂质过氧化作用，从而抑制菠菜生长。Ｏ－·２的积累能诱导抗氧化酶活性的上升，但抗氧化酶活性的上升和吸收ＵＶ的类黄酮化合物的积累并不能扭转ＵＶＢ对菠菜的伤害。
Spinach (Spinacia oleracea Mill.) cultivar “Huabo No.1” was grown in an indoor environment and treated with 13.0 kJ·m-1·d-1 of ultravioletB (UVB 280 to 320 nm) to study the effect of UVB irradiation on flavonoids and lipid peroxidation in spinach leaves. The results showed that enhanced UVB irradiation decreased the leaf fresh weight and the content of soluble protein and chlorophyll, and induced large accumulation of UVabsorbing flavonoids in the leaves. UVB irradiation also promoted the production of superoxide radicals (O-·2) and malondialdehyde in spinach leaves. However, the ascorbic acid (AsA) level was decreased under UVB treatment. It was interesting that high peroxidase (POX), superoxide dismutase (SOD) and catalase (CAT) activities in spinach leaves were induced by UVB irradiation, the former two being more sensitive. It was suggested that UVB induced the accumulation of O-·2 resulting in the lipid peroxidation and in turn inhibiting the growth of spinach. However, the increase of UVabsorbing flavonoids and antioxidative enzymes induced by high accumulation of O-·2 could not reverse the process of UVB damage.
基金
江苏省自然科学基金
国家自然科学基金
关键词
菠菜
紫外光B
类黄酮
脂质过氧化作用
抗氧化酶
Spinach, UltravioletB, Flavonoids, Lipid peroxidation, Antioxidative enzymes
