狭卵链格孢菌毒素细交链孢菌酮酸对稗草细胞膜脂质过氧化作用的影响

Effect of tenuazonic acid on lipid peroxidation of Echinochloa crus-galli leaf

为明确狭卵链格孢菌Alternaria augustiovoide菌株AAEC05-3产生的毒素细交链孢菌酮酸(tenuazonic acid,TeA)的作用机制,利用离体试验,研究了TeA对稗草叶片细胞膜脂质过氧化的影响。结果显示,低浓度TeA处理对稗草叶片的细胞膜透性和脂质过氧化影响不大;用高浓度TeA处理稗草叶片24 h后,稗草叶片细胞膜透性和脂质过氧化作用显著增强。TeA浓度为100μmol/L时,稗草叶片相对电导率和丙二醛(MDA)含量分别增加28.21%和63.58%;脂氧合酶(Lox)活性增高61.59%,且不饱和脂肪酸含量显著降低,亚油酸(18∶2)和亚麻酸(18∶3)分别降低19.56%和17.20%,脂肪酸氢过氧化物在叶片中大量积累。表明TeA可以诱导稗草叶片细胞膜的脂质过氧化作用。

In order to know the action of tenuazonic acid（TeA） produced by Alternaria augustiovoide strain AAEC05-3 on Echinochloa crus-galli（L.）,the effect of TeA on lipid peroxidation of E.crus-galli leaf was studied by leaf segment method in vitro.The result showed that low concentration TeA did not affect the membrane permeability and lipid peroxidation of E.crus-galli leaf,but the membrane permeability and lipid peroxidation increased significantly in 24 h after treatment with high concentration of TeA.When E.crus-galli leaves were treated with 100 μmol/L TeA,the relative conductivity and malondialdehyde（MDA） content increased 28.21% and 63.58%,respectively.After the treatment of 100 μmol/L TeA,lipoxygenases（Lox） activity of leaf increased 61.59%,meanwhile,the content of unsaturated fatty acids decreased dramatically.The content of linoleic acid and linolenic acid decrease 19.56% and 17.20% in 100 μmol/L TeA treatment,respectively.After the treatment of 100 μmol/L TeA,the fatty acid hydroperoxides（FAH） was largely accumulated in E.crus-galli leaf.The results indicated that TeA could induce the lipid peroxidation of E.crus-galli leave.It is deduced that the lipid peroxidation induced by TeA could be Lox-mediated lipid peroxidation.