Susceptibility of Cry1Ab maize-resistant and -susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins.

Susceptibility of Cry1Ab-resistant and -susceptible sugarcane borer (Lepidoptera: Crambidae) to four Bacillus thuringiensis toxins.

Sugarcane borer, Diatraea saccharalis (F.), is a primary corn stalk borer pest targeted by transgenic corn expressing Bacillus thuringiensis (Bt) proteins in many areas of the mid-southern region of the United States. Recently, genes encoding for Cry1A.105 and Cry2Ab2 Bt proteins were transferred into corn plants (event MON 89034) for controlling lepidopteran pests. This new generation of Bt co...

Susceptibility of dipel-resistant and -susceptible Ostrinia nubilalis (Lepidoptera: Crambidae) to individual Bacillus thuringiensis protoxins.

Dipel-resistant and -susceptible strains of Ostrinia nubilalis (Hübner) were evaluated for larval mortality and growth inhibition when fed diets containing individual Bacillus thuringiensis protoxins. Resistance ratios for four of the protoxins in Dipel (Cry1Aa, Cry1Ab, Cry1Ac, and Cry2Aa) were 170-, 205-, 524-, and > 640-fold, respectively, considerably higher than the 47-fold resistance to Di...

Analyses of Cry1Ab Binding in Resistant and Susceptible Strains of the European Corn Borer, Ostrinia nubilalis (HÃ1⁄4bner) (Lepidoptera: Crambidae)

Analyses of Cry1Ab binding in resistant and susceptible strains of the European corn borer, Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae).

Cry1Ab toxin binding analysis was performed to determine whether resistance in laboratory-selected Ostrinia nubilalis strains is associated with target site alteration. Brush border membrane vesicles were prepared using dissected midguts from late instars of susceptible and resistant strains (Europe-R and RSTT) of O. nubilalis. Immunoblot analysis indicated that three different proteins bound t...

Down-regulation of aminopeptidase N and ABC transporter subfamily G transcripts in Cry1Ab and Cry1Ac resistant Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae)

The Asian corn borer (ACB), Ostrinia furnacalis (Lepidoptera: Crambidae), is a highly destructive pest of cultivated maize throughout East Asia. Bacillus thuringiensis (Bt) crystalline protein (Cry) toxins cause mortality by a mechanism involving pore formation or signal transduction following toxin binding to receptors along the midgut lumen of susceptible insects, but this mechanism and mutat...