This study was financially supported by the Agriomics research project of the Ministry of Education, Culture, Sports, Science and Technology (H.T.), the Japan Science and Technology Agency (H.T.), Project on Technology Sirolimus molecular weight Development for Food Safety, Aichi prefecture (H.T.), the Pesticide Science Society of Japan (H.T.), and Research Fellowships from the Japan Society for the Promotion of Science for Young Scientists (Y.H.). “
“A PCR–restriction fragment length polymorphism (PCR–RFLP) method for identifying vegetative insecticidal protein (vip) 1-type genes from Bacillus cereus was developed by designing
specific primers based on the conserved regions of the genes to amplify vip1-type gene fragments. PCR products were digested with endonuclease AciI, and four known vip1-type genes were identified. Vip1Ac and vip1Aa-type genes appeared in 17 of 26 B. cereus strains. XL184 cell line A novel vip1-type gene, vip1Ac1, was identified from B. cereus strain HL12. The vip1Ac1 and vip2Ae3 genes were co-expressed in Escherichia coli strain BL21 by vector pCOLADuet-1. The binary toxin showed activity only against Aphis gossypii (Homoptera), but not for Coleptera (Tenebrio molitor, Holotrichia
oblita), Lepidoptera (Spodoptera exigua, Helicoverpa armigera, and Chilo suppressalis), Diptera (Culex quinquefasciatus). The LC50 of this binary toxin for A. gossypii is 87.5 (34.2–145.3) ng mL−1. This is probably only the second report that Vip1 and Vip2 binary toxin shows toxicity against homopteran pests. The PCR–RFLP method developed could be very useful Amisulpride for identifying novel Vip1–Vip2-type binary toxins, and the novel binary toxins, Vip1Ac1 and Vip2Ae3, identified in
this study may have applications in biological control of insects, thus avoiding potential problems of resistance. Besides insecticidal crystalline proteins (ICPs), the biocontrol agents, Bacillus thuringiensis and Bacillus cereus, can also produce insecticidal protein (Vips) during vegetative growth (Estruch et al., 1996; Warren, 1997). To date, four groups (Vip1, Vip2, Vip3, and Vip4) of Vips have been reported (http://www.lifesci.sussex.ac.uk/home/NeilCrickmore/Bt/vip.html). The binary toxin Vip1–Vip2 is coleopteran and homopteran specific, whereas Vip3 toxins have lepidopteran specificity (Estruch et al., 1996; Warren, 1997; Sattar et al., 2008). Although Vip toxins have received more research focus recently, the understanding of Vips remains very limited compared with ICPs. Vip3, the most prominent toxin of Vips, has been used to create transgenic plants with resistance against some important agricultural insect pests.