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

Abstract

<jats:p>Bacillus thuringiensis is a bacterium used for biopesticides production and pest-resistant plants due to the synthesis of protein crystals by cry genes, which are effective in controlling several insect orders such as Lepidoptera. This work aimed at the evaluation and characterisation of two new B. thuringiensis isolates active against A. gemmatalis (Hübner 1818) larvae, which is the soybean major pest. The results showed that Bt117-4 isolate amplified fragments corresponding to cry2 and cry9 genes, and synthesised protein fragments equivalent to 130, 90 and 45 kDa. The Bt3146-4 isolate amplified DNA fragments corresponding to cry9 gene and synthesised protein fragments of 70, 58 and 38 kDa. Transmission electron microscopy revealed the presence of protein crystals in both isolates. CL50 with Cry purified proteins from Bt117-4 and Bt3146-4, corresponded to 0.195 and 0.191 µg larvae-1, respectively. The two B. thuringiensis isolates selected in this study were effective to control velvetbean caterpillar at laboratory conditions. Field tests should be carried on to develop new biopesticides formulation as well for cry genes resource for Anticarsia gemmatalis resistant transgenic plants.</jats:p>

Receptors and Lethal Effect ofBacillus thuringiensisInsecticidal Crystal Proteins to theAnticarsia gemmatalis(Lepidoptera, Noctuidae)

“…However, another new B. thuringiensis ( Bt117-4 ) isolate that amplifies fragments corresponding to cry2 and cry9 genes, which synthesize protein fragments of equivalent to 130, 90, and 45 kDa [58]. The transmission electron microscopy revealed the presence of protein crystals and the CL 50 with Cry-purified proteins corresponded to 0.195  μ g/larvae of the second instar of A. gemmatalis, whose data were very similar to this paper.…”

“…The Cry1 gene of B. thuringiensis ICPs were a great promise for the control of lepidopteran pests on soybean, either as a microbial insecticide or by being genetically engineering into the soybean plant [58]. In this study, we have analysed toxicity and binding of six ICPs to larvae of A. Bioassays using trypsin-activated ICPs, and second instar of A. gemmatalis indicated that among the six proteins tested, Cry1Aa, Cry1Ac, and Cry1Ba were most active on this insect.…”

Identification of cultivable bacteria in the intestinal tract of Bactrocera dorsalis from three different populations and determination of their attractive potential

“…Interestingly, Bacillus thuringiensis (Bt) was found to be an attractant to Mexican fruit fly . It is well known that Bt acts as a pesticide and its cry proteins have already been described as toxic to several insects from the orders Lepidoptera, Diptera, Coleoptera, Hymenoptera, Homoptera and Malophaga, and also to nematodes . This indicates that some pathogenic bacteria also release attractive chemical(s) to their insect hosts.…”

Redox imbalance mediates entomotoxic effects of the conifer Araucaria angustifolia in Anticarsia gemmatalis velvetbean caterpillar

“…Considering the diverse problems associated with the massive use of these chemicals in agriculture and in environment, the biotechnology field can contribute to the discovery and development of new alternative pest control strategies (Penman, 1994). Some natural opponents including viruses (Baculovirus anticarsia) (Braconi et al, 2014;Piubelli, Hoffmann-Campo, Moscardi, Miyakubo, & de Oliveira, 2006;Piubelli, Moscardi, & Hoffmann-Campo, 2009), entomopathogenic fungi (Bertholdo-Vargas et al, 2009), and bacteria (Fiuza, Schünemann, Pinto, & Zanettini, 2012;Gobatto et al, 2010) have been used for biological control of pest populations of A. gemmatalis; however, they are not completely effective, prompting more studies to investigate better pest management strategies for agronomical applications.…”