Isolation And Identification Of Endophytic Bacterium TL2 And Its Mechanisms Of Inhibiting Fungi

264 strains which had antagonism against fungal pathogens were isolated from leaf of tea. Among them there were 14 strains were screened out for their obviously antagonism. The 14 strains were determined to inhabit the four fungal pathogens of tea leaf spot diseases and bacteria, Xanthomonas oryzae pv. oryzae. The strain TL2 was the best one. The 14 strains were further identified as Bacillus subtilis.The 14 strains were also proved to have ability to colonize inside of tea-plant and degrade cypermethrin. The strain TL2 also was the best one. They all had no significantly effect on the growth of tea plant.The results of tests on biological control mechanisms showed that the mechanisms were strongly related to O₂^- producing speed, MDA content and SOD, CAT activity. And, they were also fairly related to the PAL activity, AsA content, β -1,3-glucanases activity and exo-chitinases activity. When pathogen Pestallozzia. theae was inoculated on the tea plants, the strain TL2 could regulate the activities of SOD, CAT, PAL, β -1,3-glucanases and exo-chitinases in tea plants and promote the antagonism against pathogens.The research on antifungal proteins which secreted by the strain TL2 with two treatments (one was that TL2 was cultured in normal, the other was that TL2 was cultured with exudation of pathogen of Pestalozzia theae), the results showed that the proteins deposited by different saturated concentrations of ammonium sulfate had good inhibitive effect on the mycelia growth and the conidia germination of Pestallozzia theae. especially the proteins deposited by 30-50% , 50-70% saturated concentration of ammonium sulfate. The different protein bands of excretory protein and mycoprotein were showed by SDS-PAGE.