Fiuza L M, Schünemann R, Pinto L M N, Zanettini M H B
Programa de Pós-Graduação em Biologia, Laboratório de Microbiologia e Toxicologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.
Braz J Biol. 2012 May;72(2):363-9. doi: 10.1590/s1519-69842012000200018.
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.
苏云金芽孢杆菌是一种用于生产生物农药和培育抗虫植物的细菌，因其cry基因能合成蛋白质晶体，对控制鳞翅目等多个昆虫目有效。本研究旨在评估和鉴定两种对大豆主要害虫豆蚀叶野螟（Hübner 1818）幼虫有活性的苏云金芽孢杆菌新分离株。结果表明，Bt117 - 4分离株扩增出了与cry2和cry9基因对应的片段，并合成了相当于130、90和45 kDa的蛋白质片段。Bt3146 - 4分离株扩增出了与cry9基因对应的DNA片段，并合成了70、58和38 kDa的蛋白质片段。透射电子显微镜显示两种分离株中均存在蛋白质晶体。来自Bt117 - 4和Bt3146 - 4的Cry纯化蛋白的CL50分别为0.195和0.191 µg幼虫-1。本研究中筛选出的两种苏云金芽孢杆菌分离株在实验室条件下对豆蚀叶野螟有防治效果。应进行田间试验，以开发新的生物农药制剂，并为培育抗豆蚀叶野螟转基因植物提供cry基因资源。
