Abstract: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 100μmol/L TeA, the relative conductivity and malondialdehyde (MDA) content increased 28.21% and 63.58%, respectively. After the treatment of 100μmol/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 100μmol/L TeA treatment, respectively. After the treatment of 100μmol/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.