Binary toxins from Bacillus thuringiensis active against the western corn rootworm, Diabrotica virgifera virgifera LeConte.
The western corn rootworm, Diabrotica virgifera virgifera LeConte, is a significant pest of corn in the United States. The development of transgenic corn hybrids resistant to rootworm feeding damage depends on the identification of genes encoding insecticidal proteins toxic to rootworm larvae. In this study, a bioassay screen was used to identify several isolates of the bacterium Bacillus thuringiensis active against rootworm. These bacterial isolates each produce distinct crystal proteins with approximate molecular masses of 13 to 15 kDa and 44 kDa. Insect bioassays demonstrated that both protein classes are required for insecticidal activity against this rootworm species. The genes encoding these proteins are organized in apparent operons and are associated with other genes encoding crystal proteins of unknown function. The antirootworm proteins produced by B. thuringiensis strains EG5899 and EG9444 closely resemble previously described crystal proteins of the Cry34A and Cry35A classes. The antirootworm proteins produced by strain EG4851, designated Cry34Ba1 and Cry35Ba1, represent a new binary toxin. Genes encoding these proteins could become an important component of a sustainable resistance management strategy against this insect pest.
Baum
James A
JA
Monsanto Company, 700 Chesterfield Pkwy. West, Chesterfield, MO 63017-1732, USA. James.A.Baum@monsanto.com
Chu
Chi-Rei
CR
Rupar
Mark
M
Brown
Gregory R
GR
Donovan
William P
WP
Huesing
Joseph E
JE
Ilagan
Oliver
O
Malvar
Thomas M
TM
Pleau
Michael
M
Walters
Matthew
M
Vaughn
Ty
T
D000595:Amino Acid Sequence; D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D001483:Base Sequence; D003001:Cloning, Molecular; D001517:Coleoptera / Q000254:growth & development*; D004731:Endotoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D006460:Hemolysin Proteins; D007814:Larva / Q000254:growth & development; D008969:Molecular Sequence Data; D010572:Pest Control, Biological; D017422:Sequence Analysis, DNA; D003313:Zea mays / Q000469:parasitology*
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis