Co-expression of Bacillus thuringiensis Cry4Ba and Cyt2Aa2 in Escherichia coli revealed high synergism against Aedes aegypti and Culex quinquefasciatus larvae.
Cry4Ba is a delta-endotoxin produced by Bacillus thuringiensis subsp. israelensis and Cyt2Aa2 is a cytolytic delta-endotoxin produced by B. thuringiensis subsp. darmstadiensis. Cry4Ba produced in Escherichia coli was toxic to Aedes aegypti larvae (LC(50)=140 ng ml(-1)) but virtually inactive to Culex quinquefasciatus larvae. Cyt2Aa2 expressed in E. coli exhibited moderate activity against A. aegypti and C. quinquefasciatus larvae with LC(50) values of 350 and 250 ng ml(-1), respectively. Co-expression of both toxins in E. coli dramatically increased toxicity to both A. aegypti andC. quinquefasciatus larvae (LC(50)=7 and 20 ng ml(-1), respectively). This is the first report to demonstrate that Cry4Ba and Cyt2Aa2 have high synergistic activity against C. quinquefasciatus larvae.
Promdonkoy
Boonhiang
B
National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand. boonhiang@biotec.or.th
Promdonkoy
Patcharee
P
Panyim
Sakol
S
D000330:Aedes / Q000187:drug effects* / Q000254:growth & development; D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity*; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity*; D003465:Culex / Q000187:drug effects* / Q000254:growth & development; D004357:Drug Synergism; D004731:Endotoxins / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity*; D048168:Escherichia coli K12 / Q000235:genetics / Q000378:metabolism*; D006460:Hemolysin Proteins; D007814:Larva / Q000187:drug effects; D010572:Pest Control, Biological / Q000379:methods
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis