杂交竹梢枯病菌毒素蛋白纯化及致病力

Purification of the Toxic Protein from Arthrinium phaeospermum and Its Pathogenicity

撑×绿杂交竹（Bambusa pervariabilis×Dendrocalamopsis grandis）梢枯病是长江中上游退耕还林毁灭性病害之一,可造成严重的生态和经济损失。由于该病是近年来四川栽培区新发现的病害,相关研究较少,目前仅对该病的病原及发生规律（朱天辉等,2009a）、

To explore the composition and structure of Arthrinium phaeospermum toxins which cause wilt of the tender leaves and twigs of a hybrid bamboo（Bambusa pervariabilis×Dendrocalamopsis grandis）,the crude toxic proteins were extracted from the bacterium by liquid culture,ammonium sulfate precipitation and polyethylene glycol concentration.One composition（P3） with pathogenic activity was obtained by Sephadex G-100 gel chromatography and Q sepharose fast flow anion exchange resin.The sequencing result of P3 showed that the 7-ammonia-acids sequence at the N-terminal end was H2N-Ala-Gln-Ser-Val-Pro-Tyr-Gly,which had high homology with the precursor of subtilisin protease from Bacillus subtilis by the homophyly retrieval in NCBI.The molecular weight of P3（27 kD） was very close to that of subtilisin protease.The pathogenicity experiment of P3 indicated that it could cause the same typical symptom as that of the pathogen,but the reaction was quicker than that of the pathogen itself.The effectively originative concentration was 5-10 μg·mL-1,and the higher the concentration,the stronger the pathogenicity.