Skip to main content
NCBI home page
Applied and Environmental Microbiology logoLink to Applied and Environmental Microbiology
. 1996 Feb;62(2):583–586. doi: 10.1128/aem.62.2.583-586.1996

Synergistic effect of the Bacillus thuringiensis toxins CryIAa and CryIAc on the gypsy moth, Lymantria dispar.

M K Lee 1, A Curtiss 1, E Alcantara 1, D H Dean 1
PMCID: PMC167822  PMID: 8593057

Abstract

The insecticidal activity of toxins CryIAa, CryIAb, and CryIAc against Lymantria dispar (gypsy moth) and Bombyx mori (silkworm) was examined by force-feeding bioassays. Toxin CryIAa exhibited higher toxicity than toxins CryIAb and CryIAc for L. dispar and B. mori. To evaluate possible synergism among these toxins, bioassays were performed with mixtures of CryIAa and CryIAb, CryIAb and CryIAc, and CryIAa and CryIAc. Expected toxicity was calculated from the activity of each individual toxin and its proportion in the mixture by using the equation described by Tabashnik (B. E. Tabashnik, Appl. Environ. Microbiol. 58:3343-3346, 1992). Observed 50% growth-inhibitory doses were calculated from mixing experiments by probit analysis. In L. dispar bioassays, synergism was observed with a mixture of CryIAa and CryIAc while a mixture of CryIAa and CryIAb exhibited an antagonistic effect. No synergistic effect on B. mori was observed with any toxin combination. Voltage clamping assays of isolated L. dispar midguts also demonstrated that the mixture of CryIAa and CryIAc induced a greater slope of inhibition of short circuit current than did other toxin combinations.

Full Text

The Full Text of this article is available as a PDF (175.7 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chen X. J., Lee M. K., Dean D. H. Site-directed mutations in a highly conserved region of Bacillus thuringiensis delta-endotoxin affect inhibition of short circuit current across Bombyx mori midguts. Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):9041–9045. doi: 10.1073/pnas.90.19.9041. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Ge A. Z., Pfister R. M., Dean D. H. Hyperexpression of a Bacillus thuringiensis delta-endotoxin-encoding gene in Escherichia coli: properties of the product. Gene. 1990 Sep 1;93(1):49–54. doi: 10.1016/0378-1119(90)90134-d. [DOI] [PubMed] [Google Scholar]
  3. Ge A. Z., Rivers D., Milne R., Dean D. H. Functional domains of Bacillus thuringiensis insecticidal crystal proteins. Refinement of Heliothis virescens and Trichoplusia ni specificity domains on CryIA(c). J Biol Chem. 1991 Sep 25;266(27):17954–17958. [PubMed] [Google Scholar]
  4. Ge A. Z., Shivarova N. I., Dean D. H. Location of the Bombyx mori specificity domain on a Bacillus thuringiensis delta-endotoxin protein. Proc Natl Acad Sci U S A. 1989 Jun;86(11):4037–4041. doi: 10.1073/pnas.86.11.4037. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Gill S. S., Cowles E. A., Pietrantonio P. V. The mode of action of Bacillus thuringiensis endotoxins. Annu Rev Entomol. 1992;37:615–636. doi: 10.1146/annurev.en.37.010192.003151. [DOI] [PubMed] [Google Scholar]
  6. Harvey W. R., Wolfersberger M. G. Mechanism of inhibition of active potassium transport in isolated midgut of Manduca sexta by Bacillus thuringiensis endotoxin. J Exp Biol. 1979 Dec;83:293–304. doi: 10.1242/jeb.83.1.293. [DOI] [PubMed] [Google Scholar]
  7. Hofmann C., Lüthy P., Hütter R., Pliska V. Binding of the delta endotoxin from Bacillus thuringiensis to brush-border membrane vesicles of the cabbage butterfly (Pieris brassicae). Eur J Biochem. 1988 Apr 5;173(1):85–91. doi: 10.1111/j.1432-1033.1988.tb13970.x. [DOI] [PubMed] [Google Scholar]
  8. Hofmann C., Vanderbruggen H., Höfte H., Van Rie J., Jansens S., Van Mellaert H. Specificity of Bacillus thuringiensis delta-endotoxins is correlated with the presence of high-affinity binding sites in the brush border membrane of target insect midguts. Proc Natl Acad Sci U S A. 1988 Nov;85(21):7844–7848. doi: 10.1073/pnas.85.21.7844. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  10. Lee M. K., Milne R. E., Ge A. Z., Dean D. H. Location of a Bombyx mori receptor binding region on a Bacillus thuringiensis delta-endotoxin. J Biol Chem. 1992 Feb 15;267(5):3115–3121. [PubMed] [Google Scholar]
  11. Liang Y., Patel S. S., Dean D. H. Irreversible binding kinetics of Bacillus thuringiensis CryIA delta-endotoxins to gypsy moth brush border membrane vesicles is directly correlated to toxicity. J Biol Chem. 1995 Oct 20;270(42):24719–24724. doi: 10.1074/jbc.270.42.24719. [DOI] [PubMed] [Google Scholar]
  12. Moar W. J., Masson L., Brousseau R., Trumble J. T. Toxicity to Spodoptera exigua and Trichoplusia ni of individual P1 protoxins and sporulated cultures of Bacillus thuringiensis subsp. kurstaki HD-1 and NRD-12. Appl Environ Microbiol. 1990 Aug;56(8):2480–2483. doi: 10.1128/aem.56.8.2480-2483.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Rajamohan F., Alcantara E., Lee M. K., Chen X. J., Curtiss A., Dean D. H. Single amino acid changes in domain II of Bacillus thuringiensis CryIAb delta-endotoxin affect irreversible binding to Manduca sexta midgut membrane vesicles. J Bacteriol. 1995 May;177(9):2276–2282. doi: 10.1128/jb.177.9.2276-2282.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Tabashnik B. E. Evaluation of synergism among Bacillus thuringiensis toxins. Appl Environ Microbiol. 1992 Oct;58(10):3343–3346. doi: 10.1128/aem.58.10.3343-3346.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Van Rie J., Jansens S., Höfte H., Degheele D., Van Mellaert H. Specificity of Bacillus thuringiensis delta-endotoxins. Importance of specific receptors on the brush border membrane of the mid-gut of target insects. Eur J Biochem. 1989 Dec 8;186(1-2):239–247. doi: 10.1111/j.1432-1033.1989.tb15201.x. [DOI] [PubMed] [Google Scholar]
  16. Van Rie J., McGaughey W. H., Johnson D. E., Barnett B. D., Van Mellaert H. Mechanism of insect resistance to the microbial insecticide Bacillus thuringiensis. Science. 1990 Jan 5;247(4938):72–74. doi: 10.1126/science.2294593. [DOI] [PubMed] [Google Scholar]
  17. van Frankenhuyzen K., Gringorten J. L., Milne R. E., Gauthier D., Pusztai M., Brousseau R., Masson L. Specificity of Activated CryIA Proteins from Bacillus thuringiensis subsp. kurstaki HD-1 for Defoliating Forest Lepidoptera. Appl Environ Microbiol. 1991 Jun;57(6):1650–1655. doi: 10.1128/aem.57.6.1650-1655.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Applied and Environmental Microbiology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES