These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Efficient constitutive expression of chitinase in the mother cell of Bacillus thuringiensis and its potential to enhance the toxicity of Cry1Ac protoxin.
    Author: Hu SB, Liu P, Ding XZ, Yan L, Sun YJ, Zhang YM, Li WP, Xia LQ.
    Journal: Appl Microbiol Biotechnol; 2009 Apr; 82(6):1157-67. PubMed ID: 19277644.
    Abstract:
    Previous studies revealed that chitinase could enhance the insecticidal activity of Bacillus thuringiensis and it has been used in combination with B. thuringiensis widely. However, the expression of B. thuringiensis chitinase is rather low and needs induction by chitin, which limits its field application. It would make sense to constitutively express the chitinase at a sufficiently high level to offer advantages in biological control of pests. In this study, a signal peptide-encoding sequence-deleted chitinase gene from B. thuringiensis strain 4.0718 under the control of dual overlapping promoters plus Shine-Dalgarno sequence and terminator sequence of cry1Ac3 gene was cloned into shuttle vector pHT315 and introduced into an acrystalliferous B. thuringiensis strain Cry(-)B. The recombinant plasmid was stably maintained over 240 generations in Cry(-)B. Chitinase was overexpressed within the sporangial mother cells in the form of spherical crystal-like inclusion bodies. The chitinase inclusions could be solubilized and exhibit chitinolytic activity in 30 mmol l(-1) Na(2)CO(3)-0.2% beta-mercaptoethanol buffer at a wide range of alkaline pH values, and what's more, the chitinase inclusions potentiated the insecticidal effect of Cry1Ac protoxin when used against larvae of Spodoptera exigua and Helicoverpa armigera.
    [Abstract] [Full Text] [Related] [New Search]