Isolation And Characterization Of The Toxic Protein Excreted By Vertillium Dahliae

Cotton Verticillium wilt caused by Verticillium dahliae(Vd) is one of the major diseases which seriously affect the cotton production in the world. Although much progress has been made in prevention and control of cotton Verticillium wilt, the progess is slow. The most important reason is that the basic research about the pathogenic mechanism of Verticillium dahliae is far from enough except the lack of resistant resources. It has been proven that the key pathogenic factor is a kind of protein-lipopolysaccharide complex (PLPC) excreted by Verticillium dahliae, but no such PLPC has been isolated and characterized update. So it is very important to isolatae and characterize such PLPC for clarifing the pathogenic mechanism of Verticillium dahliae.In this work, a crude Vd phytotoxic protein with high bioactivity, high temprature resistance, acid and alkali resistances has been isolated from the culture medium of Verticillium dahliae. The toxic protein has been further purified using various methods including a combination of ion-exchange, molecular exclusion chromatography, affinity chromatography and C18 reversed-phase chromatography. The Vd protein thus obtained and showed a molecular weight of 1800Da by MALDI-TOF-MA analysis.