Binary insecticidal crystal protein from Bacillus thuringiensis, strain PS149B1: effects of individual protein components and mixtures in laboratory bioassays.
A family of novel binary insecticidal crystal proteins, with activity against western corn rootworm, Diabrotica virgifera virgifera LeConte, was identified from Bacillus thuringiensis Berliner. A binary insecticidal crystal protein (bICP) from B. thuringiensis strain PS149B1 is composed of a 14-kDa protein (Cry34Abl) and a 44-kDaprotein (Cry35Ab1). These proteins have been co-expressed in transgenic maize plants, Zea mays L., and effectively control western corn rootworm larvae under field conditions. Laboratory experiments were conducted to better understand the contribution of each component protein to the in vivo activity of the bICP. The 14-kDa protein is active alone against southern corn rootworm, Diabrotica undecimpunctata howardi Barber, and was synergized by the 44-kDa protein. In mixtures, the concentration of the 14-kDa protein had a greater impact on efficacy than the 44-kDa component. Although both proteins are clearly required for maximal insecticidal activity, laboratory results did not support the formation of a stable, fixed-ratio complex of the two component proteins.
Herman
Rod A
RA
Regulatory Laboratories, Dow AgroSciences LLC, Indianapolis, IN 46268, USA. raherman@dowagro.com
Scherer
Peter N
PN
Young
Debra L
DL
Mihaliak
Charles A
CA
Meade
Thomas
T
Woodsworth
Aaron T
AT
Stockhoff
Brian A
BA
Narva
Kenneth E
KE
D000818:Animals; D001413:Bacillus thuringiensis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000494:pharmacology*; D001427:Bacterial Toxins; D001681:Biological Assay; D001517:Coleoptera / Q000187:drug effects* / Q000254:growth & development; D004731:Endotoxins / Q000494:pharmacology*; D006460:Hemolysin Proteins; D007306:Insecticides / Q000494:pharmacology*; D015233:Models, Statistical; D010572:Pest Control, Biological
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis