title: Weak transcription of the cry1Ac gene in nonsporulating Bacillus thuringiensis cells.
abstract: The cry1Ac gene of Bacillus thuringiensis subsp. kurstaki HD-73 (B. thuringiensis HD-73) is a typical example of a sporulation-dependent crystal gene and is controlled by sigma E and sigma K during sporulation. To monitor the production and accumulation of Cry1Ac at the cellular level, we developed a green fluorescent protein-based reporter system. The production of Cry1Ac was monitored in spo0A, sigE, and sigK mutants, and these mutants were able to express the Cry1Ac-green fluorescent protein fusion protein. In nonsporulating B. thuringiensis HD-73 cells, low-level expression of cry1Ac was also observed. Reverse transcription-PCR and Western blotting results confirmed that the cry1Ac promoter has low activity in nonsporulating B. thuringiensis cells. A beta-galactosidase assay demonstrated that the transcription of the cry1Ac gene during exponential and transition phases is positively regulated by Spo0A. Additional bioassay results indicated that spo0A and sigE mutants containing the cry1Ac-gfp fusion exhibited insecticidal activity against Plutella xylostella larvae.
authors: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors: Hui
authors: H
authors: Yang
authors: Pinshu
authors: P
authors: Wang
authors: Qi
authors: Q
authors: Peng
authors: Rong
authors: R
authors: Rong
authors: Chunxia
authors: C
authors: Liu
authors: Didier
authors: D
authors: Lereclus
authors: Jie
authors: J
authors: Zhang
authors: Fuping
authors: F
authors: Song
authors: Dafang
authors: D
authors: Huang
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics* / Q000254:growth & development; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D015153:Blotting, Western; D004731:Endotoxins / Q000235:genetics*; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006460:Hemolysin Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D013171:Spores, Bacterial / Q000235:genetics* / Q000254:growth & development; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D011993:Recombinant Fusion Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D049452:Green Fluorescent Proteins; D001616:beta-Galactosidase