Separation, characters and biological functions of Erwiniachrysanthemi pv. zeae toxin
水稻基腐细菌毒素的分离纯化、性质和生物学作用

Abstract: Objective] The toxin produced by Erwinia chrysanthemi pv. zeae has not been reported so far. Toxin is one of the important pathogenic factors for plant pathogenic bacteria. The separation and purification of toxin are the key and basal work for toxin functional study. Methods] We used several chromatography columns, chemical and biochemical methods for Erwinia chrysanthemi pv. zeae toxin separation and its characterization. Results] We obtained a pure ingre-dient T3 of Erwinia chrysanthemi pv. zeae toxin . It was a yellow solid and dissolved in methanol, N-butyl alcohol(NBA), water and formic acid. It dissolved weakly in acetone but did not dissolve in trichloromethane and ethyl acetate. The re-sults showed that T3 toxin ingredient was neither carbohydrate nor protein, and was sensitive to ultraviolet ray. Biological assays of the toxin showed that it could inhibit rice growth, cause rice seedlings to wilt and make tobacco cells necrosis. Toxin with high content could inhibit buds and roots of rice, corn, tomato and tobacco to grow, whereas toxin with low content could promote their growth. In addition, the toxin inhibited 10 plant pathogenic bacteria with 5 genera. Further-more, toxin T3 induced the activities of phenylalanine ammonia-lysae(PAL) and peroxidase(POD) in rice. Conclusions] It is the first report about the separation and purification of E.chrysanthemi pv.zeae toxin. The T3 toxin of E. chrysanthemi pv.zeae had the biological characters with inhibiting plant seeds germination, causing rice seedlings wilt, inhibiting some plant pathogenic bacteria and inducing defense enzyme activities in rice.