Production Of Botrytis Cinerea Toxin And Pathogenic Effects On Tomato Plant

Toxin was a kind of secondary metabolites of plant pathogens. It had important effect in course of diseases because pathogens could use toxin as chemical weapon attack host plant. We had felt that study on the toxin could lead to a greater understanding of the pathogenic factors of pathogens, pathological alteration of host plants in cell structure, and pathogenic mechanisms of pathogens.Botrytis cinerea was a kind of important pathogen of plant and could produce toxin (BC-toxin) in liquid culture. The crude BC-toxin was obtained from the cultured filtrate when it was extracted with chloroform and then chloroform in extracted produce was evaporated. The biological activity assay of the crude toxin showed that it could induce the similar symptom of tomato leaf grey mould, and inhibit the growth of tomato radicle and make the seedling wilting. According to the above results we concluded that BC-toxin had toxicity to tomato plant and seed.The culture condition for the production of Botrytis cinerea toxin was studied. It was appropriate for the toxin production as follows: The optimum medium was improved FriesⅢmedium, in which pH value was 6. The strains was cultured for 20~25days at 22~25℃, with darkness and no shake.The crude BC-toxin obviously damaged the cell membrane of tomato leaf. The permeability of cell membranes was changed and the electrolytes in the cells outflowed when tomato leaves were treated by the crude toxin. When tomato leaves were treated by the crude toxin diluted 50 times, the damage rate of toxin to cell membranes was above 90%. Though the crude toxin was diluted 200 times the damage rate to cell membrane of tomato leaf was 39.13%. There was a distinct difference in damage rate of tomato leaves cells which were treated by toxin at different time. When leaves were treated by the toxin for 1 hour the permeability of cell membranes had exhibited mild alteration and the longer the treatment time was, the more serious the damage was.The observation by transmission electron microscope (TEM) showed that the crude toxin could seriously destroy the cells and cell ultramicroscopic structures of tomato leaf. The obvious change on the leaf cell ultrastructure was observed, such as cell membrane separated from cell wall and broken, vacuoles disappeared, chloroplast membrane damaged and chloroplast lamella swollen and in disorder, mitochondrial disappeared, and the leaf cell breakdown. In despite of diluted 200 times the crude toxin could injure tomato leave cells. When treated by the toxin for 3 hours the cell ultrastructure of tomato leaves had revealed ravages. On condition that leaves treated by the crude toxin for 12 hours the cell structure was strongly damaged, some organelles dissolved, and the cells were completely collapsed. Key words: for 1 hour the permeability of cell membranes had exhibited mild alteration and the longer the treatment time was, the more serious the damage was. The observation by transmission electron microscope (TEM) showed that the crude toxin could seriously destroy the cells and cell ultramicroscopic structures of tomato leaf. The obvious change on the leaf cell ultrastructure was observed, such as cell membrane separated from cell wall and broken, vacuoles disappeared, chloroplast membrane damaged and chloroplast lamella swollen and in disorder, mitochondrial disappeared, and the leaf cell breakdown. In despite of diluted 200 times the crude toxin could injure tomato leave cells. When treated by the toxin for 3 hours the cell ultrastructure of tomato leaves had revealed ravages. On condition that leaves treated by the crude toxin for 12 hours the cell structure was strongly damaged, some organelles dissolved, and the cells were completely collapsed.