棉 花 学 报 Cotton Science 2006，18(2)：79-82
Effect of Cupric Complexes of Amino Acid on Secreted Toxic Protein from Verticillium dahliae Abstract：Verticillium wilt of cotton plant which infected by Verticillium dahliae is a kind of plant fungal disease in the vascular bundle. In this research，we used cupric complexes of alanine，cupric complexes of glycine，cupric complexes of glutamic acid，cupric complexes of threonine and cupric complexes of mixed amino-acid to test the inhibition on the Verticillium dahlia. These five fungicides were developed by our laboratory as new kinds of antiseptic. Verticillium dahliae was cultured in the Czapeck's culture solution which added the cupric complexes of amino-acid at 25 ℃，and the control added aseptic water. After 20 days we extracted the secreted protein of Verticillium dahliae cultured in the solution，then isolated the protein by anion-exchange chromatography，and the area of the chromatographic peak can indicate the amount of every collection. At the same time，we collected every isolated parts，respectively，to test the activity. In the wilt-test，we cultured the cotton seedlings in a certain nutrition solution， after they grew out four pieces of leaves，we selected the healthy seedlings as the wilt-test materials. the phytotoxic protein was added in the nutrition solution culturing cotton seedlings，then we observed the growth of the seedlings in 24-72 h. By analyzing the chromatographic peak and the wilt-test accordingly， it showed that cupric complexes of alanine，cupric complexes of glycine，cupric complexes of glutamic acid and cupric complexes of mixed amino-acid could inhibit the formation of microsclerotia and reduce the secretion of the phytotoxic protein of Verticillium dahliae，but cupric complexes of threonine increased the secreted protein. Furthermore，neither of the wilt-tests showed that the five fungicides could-inhibit the activity of the phytotoxic protein. All results indicated that the inhibition of the five cupric complexes of amino-acid antiseptic on the verticillium wilt of cotton plant by the decrease of the amount of the phytotoxic protein. But the reason that cupric complexes of threonine increased the secreted protein is not clear.To compare the inhibiting effect of cupric complexes of mixed amino-acid and the four single ingredient fungicides，it showed that all kinds of cupric complexes of amino-acid had different effects on the Verticillium dahliae so the ingredients in the cupric complexes of mixed amino-acid interacted cooperatively to inhibit Verticillium dahliae.
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