Combined analysis of supernatant-based feeding bioassays and PCR as a first-tier screening strategy for Vip -derived activities in Bacillus thuringiensis strains effective against tropical fall armyworm.
J Appl Microbiol
; 93(2): 269-77, 2002.
Article
em En
| MEDLINE
| ID: mdl-12147075
AIMS: To assess whether feeding bioassays using culture-supernatant proteins could be combined with PCR into a first-tier screening strategy for Vip3A-like genes efficient against tropical Spodoptera frugiperda. METHODS AND RESULTS: Out of 12 Bacillus thuringiensis strains studied, the total protein concentrated from the culture supernatant of only the strain HD125 yielded a significantly increased armyworm mortality and an intense band of the predicted size for VIP3A protein in SDS-PAGE. However, PCR and sequencing data indicated Vip-like genes are ubiquitous in tropical B. thuringiensis isolates. Interestingly, the HD125 strain was also the only one displaying a single-band amplification pattern and the highest sequence identity to the reported Vip3A(a) gene. CONCLUSIONS: Results suggest the insecticidal effectiveness of putative VIPs in B. thuringiensis isolates can be preliminarily estimated by the use of supernatant-derived total protein in feeding experiments, though only in a limited manner. SIGNIFICANCE AND IMPACT OF THE STUDY: A simple and cost-effective first-tier screening strategy for VIP-derived activities in B. thuringiensis collections can be developed by combining PCR and feeding bioassays. Moreover, the employed primers showed to be useful as a tool for strains differentiation at DNA level, and for characterization and isolation of Vip-like genes in tropical B. thuringiensis germplasm.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bacillus thuringiensis
/
Proteínas de Bactérias
/
Bioensaio
/
Spodoptera
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
/
Screening_studies
Limite:
Animals
Idioma:
En
Revista:
J Appl Microbiol
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido