In 1987, Vaeck and Fischhoff reported the transformation of the B. thuringiensis (abbreviated to B. t. ) δ-endotoxin gene into tobacco and tomato respectively, and obtained the transgenic plants. Since then, more att...In 1987, Vaeck and Fischhoff reported the transformation of the B. thuringiensis (abbreviated to B. t. ) δ-endotoxin gene into tobacco and tomato respectively, and obtained the transgenic plants. Since then, more attention has been paid to plant resistance to insect attack by plant genetic engineering.展开更多
Baculoviruses have been widely used as biological agents because of their specificpathogenicity for target insect and harmlessness to mammals, birds and plants as well asadvantages with persistence and epidemics as pe...Baculoviruses have been widely used as biological agents because of their specificpathogenicity for target insect and harmlessness to mammals, birds and plants as well asadvantages with persistence and epidemics as pestcides. A major drawback for morewide-spread use of these viruses is their low virulenee and slow speed of action, which re-stricted their use. No enhancement in pathogenicity of recombinant viruses was observedwith insertion of the Bacillus thuringiensis full-length endotoxin cryIA(c) and cryIA(b) geneinto the AcNOV (Autographa californica nuclear polyhedrosis virus) genome under the con-trol of polyhedrin gene promoter. The reason may be that protoxin, full-length genesproduct of recombinant virus in infected insect cells, which was short of insect gut alkalienvironment, cannot be degraded into active toxic polypeptide. Expression level of 3’展开更多
In this study, we rapidly identified Bacillus thuringiensis 4.0718 strain that harbored the known cry1 and cry2 type genes by a PCR strategy. Three pairs of universal oligonucleotide primers were designed to detect al...In this study, we rapidly identified Bacillus thuringiensis 4.0718 strain that harbored the known cry1 and cry2 type genes by a PCR strategy. Three pairs of universal oligonucleotide primers were designed to detect all known cry1, cry2 and cry3 type gene sequences. Then the DNA of the positive strain 4.0718 was probed with a set of specific primers. One feacture of this screening method was that each gene was expected to produce a PCR product having a precise molecular weight. PCR products having different sizes probably represented the gene was a potentially novel gene. Differentiations among these genes was determined on the basis of the electrophoresis patterns of PCR products. Finally, five cry1 type genes (cry1Aa, cry1Ab, cry1Ac, cry1Cb, a novel cry4.5 type genes) and one cry2Ac type gene had been detected from Bacillus thuringiensis 4.0718 strain.展开更多
文摘In 1987, Vaeck and Fischhoff reported the transformation of the B. thuringiensis (abbreviated to B. t. ) δ-endotoxin gene into tobacco and tomato respectively, and obtained the transgenic plants. Since then, more attention has been paid to plant resistance to insect attack by plant genetic engineering.
文摘Baculoviruses have been widely used as biological agents because of their specificpathogenicity for target insect and harmlessness to mammals, birds and plants as well asadvantages with persistence and epidemics as pestcides. A major drawback for morewide-spread use of these viruses is their low virulenee and slow speed of action, which re-stricted their use. No enhancement in pathogenicity of recombinant viruses was observedwith insertion of the Bacillus thuringiensis full-length endotoxin cryIA(c) and cryIA(b) geneinto the AcNOV (Autographa californica nuclear polyhedrosis virus) genome under the con-trol of polyhedrin gene promoter. The reason may be that protoxin, full-length genesproduct of recombinant virus in infected insect cells, which was short of insect gut alkalienvironment, cannot be degraded into active toxic polypeptide. Expression level of 3’
文摘In this study, we rapidly identified Bacillus thuringiensis 4.0718 strain that harbored the known cry1 and cry2 type genes by a PCR strategy. Three pairs of universal oligonucleotide primers were designed to detect all known cry1, cry2 and cry3 type gene sequences. Then the DNA of the positive strain 4.0718 was probed with a set of specific primers. One feacture of this screening method was that each gene was expected to produce a PCR product having a precise molecular weight. PCR products having different sizes probably represented the gene was a potentially novel gene. Differentiations among these genes was determined on the basis of the electrophoresis patterns of PCR products. Finally, five cry1 type genes (cry1Aa, cry1Ab, cry1Ac, cry1Cb, a novel cry4.5 type genes) and one cry2Ac type gene had been detected from Bacillus thuringiensis 4.0718 strain.
