Occurrence and linkage between secreted insecticidal toxins in natural isolates of Bacillus thuringiensis.
Little is known about the occurrence and linkage between secreted insecticidal virulence factors in natural populations of Bacillus thuringiensis (Bt). We carried out a survey of 392 Bt strains isolated from various samples originating from 31 countries. The toxicity profile of the culture supernatants of these strains was determined individually against Anthonomus grandis (Coleoptera) and Spodoptera littoralis (Lepidoptera). We analyzed beta-exotoxin I production and searched for the genes encoding Vip1-2, Vip3, and Cry1I toxins in 125 of these strains. Our results showed that these insecticidal toxins were widespread in Bt but that their distribution was nonrandom, with significant linkage observed between vip3 and cry1I and between vip1-2 and beta-exotoxin I. Strains producing significant amounts of beta-exotoxin I were more frequently isolated from invertebrate samples than from dust, water, soil, or plant samples.
Espinasse
Sylvain
S
Unité de Recherches de Lutte Biologique, INRA La Minière, 78285 Guyancourt, France.
Chaufaux
Josette
J
Buisson
Christophe
C
Perchat
Stéphane
S
Gohar
Michel
M
Bourguet
Denis
D
Sanchis
Vincent
V
D000241:Adenosine / Q000031:analogs & derivatives* / Q000032:analysis; D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics* / Q000633:toxicity; D001517:Coleoptera / Q000254:growth & development; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D004731:Endotoxins / Q000235:genetics*; D006460:Hemolysin Proteins; D010572:Pest Control, Biological / Q000379:methods; D016133:Polymerase Chain Reaction; D018411:Spodoptera / Q000254:growth & development; D013400:Sugar Acids / Q000032:analysis; D037521:Virulence Factors / Q000032:analysis / Q000235:genetics
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; D013400:Sugar Acids; C447139:Vip3A protein, Bacillus thuringiensis; D037521:Virulence Factors; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C068295:thuringiensin; D000241:Adenosine