Construction Of Bacillus Thuringiensis Genetic Modified Strain With Resistance To Plant Disease

In order to construct a genetic modified engineering strain with resistance to plant disease, the plant activator protein was displayed on the cell surface of Bacillus thuringiensis with thehelp of slayer protein. The result was this constructed Genetic Modified strain had resistance to plant disease. On the other hand, we studied the factors affecting the germination of the spore of Bacillus thuringiensis. The chief results are described as below.1. Construction of Genetic Modified strain with resistance to plant disease using plant activator proteinPlant activator protein was produced by many fungi such as Alternaria spp, it was a novel protein purified by Dr D W Qiu. the first time. This protein could elicit highlevel expression of pathogenesisrelated gene or enzyme of plant by systemic acquired resistance(SAR) in short time, and immune system of plant itself was enhanced, which results that the plant shows highly activity against a wide range of plant disease caused by pathogenic fungi and bacteria. Up to the present, there is no reported about its expression in bacteria and construction of genetic modified engineering strain. In this work, the promoter of gene ap36 was replaced with the promoter of gene ctc, which is the gene of the s-layer protein of Bacillus thuringiensis strain CTC, constructing the slh-ap36 fusin gene, this fusion gene was transformed to Bacillus thuringiensis plasmid-free derivative strain 171, constructed the strain BMB0588 carried the fusion gene slh-ap36. In order to investigate the induced ability of BMB0588, tomato treated with this strain, the result show the activity of pathogenesis related enzyme were increased Furthermore, it exhibited higher restraint to the potato rot disease caused by Erwinia carotovora SCG1.2 Studying on the factors affecting the spore germination of Bacillus thuringiensisThe chief component of Bt pesticide is the mixture of spore and crystal protein, In this kind of pesticide, the spore has a large scale, the spore is hard to germination in nature contion. This directly affect its effect.As we know, the chief component of BMB0588 is the fusion protein SLH-Ap36, it is expressed during the vegetable phage, it is diffcult to exert its effecf during the spore phage. In order to solve the problem, we investigate the factors(temperature, amino acid and carbon resource)affecting the spore germination of Bacillus thuringiensis plasmid-ffee derivative strain 171. The result show: the germination efficiency of BMB171 spore is 70% aftered 4h treated with 45(?); their germination efficiency of BMB171 spore is 40% aflered 4h treated with L-Ala(0.5mM) and LCys(0.5mM) respectively; and sucrose and glucose had no direct effect on spore germination. of Bacillus thuringiensis, but the Glucose and sucrose could increase the germination efficiency when one of them coupied with L-Ala. The spore germination efficiency of BMB171 is 99% after 10h at 45(?) when existing L-Ala(0.5mM) and Glucose(4.5 mM) simultaneously.