[Effect of quorum sensing response regulator nprR deletion on expression of cry protein in Bacillus thuringiensis].
OBJECTIVE
The role of Quroum Sensing response regulator nprR on the expression of Cry protein in B. thuringiensis HD-73 was studied.


METHODS
The nprR gene deletion mutant HD73 (delta nprR) was constructed by using of homologous recombination. Beta-galactosidase assay of cry1Ac'-lacZ gene fusion and SDS-PAGE in both HD-73 and HD73 (delta nprR) strains were performed to analyze the effect of nprR gene deletion on expression of cry1lAc gene.


RESULTS
Beta-galactosidase assay of nprR'-lacZ in both LB and Schaeffer' s sporulation medium showed nprR gene in B. thuringiensis was initially transcripted at TO (end of Logarithmic growth phase) and keeping expression in stationary phase. Beta-galactosidase assay of cry1Ac'-lacZ and SDS-PAGE indicated that expression of cry1Ac gene in HD73 (delta nprR) was stronger than that in HD-73 during transition phase and early stationary phase. However, Cry expressed product between HD-73 and HD73 (delta nprR) in LB medium has no significant difference when crystal and spore were released.


CONCLUSIONS
The deletion of nprR increased expression and transcription activity of cry1Ac during transition and early stationary phase in rich media.
State Key Laboratory for Biology of Plant Diseases and Insect Pest, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. wangyao18@hotmail.com
Yao
Y
Wang
Chao
C
Deng
Qi
Q
Peng
Zhen
Z
Chen
Dafang
D
Huang
Jie
J
Zhang
Fuping
F
Song
D001413:Bacillus thuringiensis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004731:Endotoxins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism; D053038:Quorum Sensing
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis