Institut Charles Gerhardt Montpellier, Equipe MACS, 8 rue de l'Ecole normale, Montpellier Cedex 5, France.
Arch Microbiol. 2014 Jun;196(6):435-44. doi: 10.1007/s00203-014-0981-3. Epub 2014 Apr 9.
The aim of this study was to characterize new Bacillus thuringiensis strains that have a potent insecticidal activity against Ephestia kuehniella larvae. Strains harboring cry1A genes were tested for their toxicity, and the Lip strain showed a higher insecticidal activity compared to that of the reference strain HD1 (LC50 of Lip and HD1 were 33.27 and 128.61 μg toxin/g semolina, respectively). B. thuringiensis Lip harbors and expresses cry1Aa, cry1Ab, cry1Ac, cry1Ad and cry2A. DNA sequencing revealed several polymorphisms in Lip Cry1Aa and Cry1Ac compared to the corresponding proteins of HD1. The activation process using Ephestia kuehniella midgut juice showed that Lip Cry1A proteins were more stable in the presence of larval proteases. Moreover, LipCry1A proteins exhibited higher insecticidal activity against these larvae. These results indicate that Lip is an interesting strain that could be used as an alternative to the worldwide used strain HD1.
本研究旨在鉴定对粉斑螟幼虫具有强烈杀虫活性的新型苏云金芽孢杆菌菌株。对携带 cry1A 基因的菌株进行了毒性测试，结果表明 Lip 菌株比参考菌株 HD1 的杀虫活性更高（Lip 和 HD1 的 LC50 分别为 33.27 和 128.61μg 毒素/g 粗粒粉）。苏云金芽孢杆菌 Lip 菌株携带并表达 cry1Aa、cry1Ab、cry1Ac、cry1Ad 和 cry2A。DNA 测序结果显示，与 HD1 相应蛋白相比，LipCry1Aa 和 Cry1Ac 存在多个多态性。使用粉斑螟中肠汁液进行的激活过程表明，LipCry1A 蛋白在存在幼虫蛋白酶的情况下更稳定。此外，LipCry1A 蛋白对这些幼虫表现出更高的杀虫活性。这些结果表明，Lip 是一种很有前途的菌株，可作为全球使用的菌株 HD1 的替代品。
