Song Feifei, Lin Yunfeng, Chen Chen, Shao Ensi, Guan Xiong, Huang Zhipeng
Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, P.R. China.
China National Engineering Research Center of JUNCAO Technology, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, P.R. China.
J Microbiol Biotechnol. 2016 Oct 28;26(10):1774-1780. doi: 10.4014/jmb.1604.04090.
Vegetative insecticidal proteins (Vips) are insecticidal proteins synthesized by during the vegetative stage of growth. In this study, Vip3Aa protein, obtained by in vitro expression of the gene from WB5, displayed high insecticidal activity against aside from and . Bioassay results showed that the toxicity of Vip3Aa protein against larvae statistically decreased along with the increase of the age of the larvae, with LC = 2.609 ng/cm for neonatal larvae, LC = 28.778 ng/cm for first instar larvae, LC = 70.460 ng/cm for second instar larvae, and LC = 200.627 ng/cm for third instar larvae. The accumulative mortality of 100% larvae appeared at 72 h for all instars of larvae, when feeding respectively with 83.22, 213.04, 341.40, and 613.20 ng/cm of Vip3Aa toxin to the neonatal and first to third instar larvae. The histopathological effects of Vip3Aa toxin on the midgut epithelial cells of larvae was also investigated. The TEM observations showed wide damage of the epithelial cell in the midgut of larvae fed with Vip3Aa toxin.
营养期杀虫蛋白（Vips）是细菌在生长的营养阶段合成的杀虫蛋白。在本研究中，通过体外表达苏云金芽孢杆菌WB5的vip3Aa基因获得的Vip3Aa蛋白，除小菜蛾和棉铃虫外，对甜菜夜蛾也表现出高杀虫活性。生物测定结果表明，Vip3Aa蛋白对甜菜夜蛾幼虫的毒性随幼虫龄期的增加而在统计学上显著降低，其中，初孵幼虫的LC50为2.609 ng/cm²，一龄幼虫为28.778 ng/cm²，二龄幼虫为70.460 ng/cm²，三龄幼虫为200.627 ng/cm²。当分别用83.22、213.04、341.40和613.20 ng/cm²的Vip3Aa毒素饲喂甜菜夜蛾初孵幼虫及一至三龄幼虫时，所有龄期的幼虫在72 h时累积死亡率均达到100%。同时还研究了Vip3Aa毒素对甜菜夜蛾幼虫中肠上皮细胞的组织病理学影响。透射电镜观察显示，用Vip3Aa毒素处理的甜菜夜蛾幼虫中肠上皮细胞受到广泛损伤。
