Cry1B and Cry3A are active against Hypothenemus hampei Ferrari (Coleoptera: Scolytidae)

Two new Brazilian isolates of Bacillus thuringiensis toxic to Anticarsia gemmatalis (Lepidoptera: Noctuidae)

“…lifesci.sussex.ac.uk/home/Neil_Crickmore/Bt). Cry proteins have already been described as toxic to several insect from Lepidoptera, Diptera, Coleoptera, Hymenoptera, Homoptera, and Malophaga orders (Zhong et al, 2000;De Maagd et al, 2001;Castilhos-Fortes et al 2002;Martins et al, 2004;Nazarian et al, 2009;López-Pazos et al, 2009) and also to nematodes (Marroquin et al, 2000;Jouzani et al, 2008).…”

Biological Activity of Insecticidal Toxins: Structural Basis, Site-Directed Mutagenesis and Perspectives

“…Any signals in the ligand blot for Cry1B and Cry3A would be related with these proteic groups. However, we identified the minor biological activity of Cry1B and Cry3A proteins on CBB larvae (López-Pazos et al 2009a); and none was seen Specifically, Cry4 and Cry9 were prepared for cloning by PCR amplification using the primers Cry4F (5'-ATGGGATCCTATCAAAATAAAAATGAATAT-3') with Cry4R (5'-TCACTCGTTCATGCCTGCAGATTCAAT GCT-3') and Cry9F (5'-ATGGGTACCAATAAACACGGAATTATTGGC-3') with Cry9R (5'-TTACTGCAGTGTTTCAACGAA TTCAATACT-3'), respectively. BamHI and KpnI restriction sites were added to the sequences of the Cry4 and Cry9 forward primers (underlined), respectively.…”

“…Although the Cry1B and Cry3A proteins showed minor activity against the pest, the results support the hypothesis that toxicity could be indirect and due to physiological factors of the insect rather than directly from the toxicity of dedicated toxin molecules. Unfortunately the Cry1I, Cry4, Cry9 and SN1917 hybrids were not toxic to CBB (López-Pazos et al 2010, 2009a. We wanted to learn about the possible interaction between Cry toxins and the receptors in midgut CBB.…”

“…Brush border membrane vesicles (BBMVs) from the midgut of H. hampei were prepared according to Wolfersberger et al (1987). We used the Cry1B, Cry1I, Cry3A (López-Pazos et al 2009a;López-Pazos et al 2010), Cry4 and Cry9 proteins ( Figure 6). BBMVs divided by protein electrophoresis showed bands between 20-220 kDa (Figure 6).…”

“…The specific conditions in CBB gut physiology (acidic pH, types of proteases or high proportions of insecticide resistance alleles) are not favourable to the modes of action of the Cry proteins (López-Pazos et al 2009a). The presence of candidate receptors for Cry proteins in CBB offers evidence for the potential of Cry protein use for the control of this pest.…”