Serraia nematodiphila R187饲喂侵染黑腹果蝇的胃毒活性研究
时间:2018-07-17 21:32 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：在倡导绿色农业的大背景下，昆虫病原线虫与其共生菌形成的共生体作为一种有效的新型生物杀虫剂具有很大的研究价值。Serratia nematodiphila R187是从昆虫病原线虫Heterorhabditidoides rugaoensis中分离出的一株共生菌，它具有强毒性，具有很强的杀虫效果。本研究以黑腹果蝇为靶标昆虫，以饲喂共生菌的方式来实现侵染目的，进而研究其对果蝇的胃毒活性。结果表明，S. nematodiphila R187可以杀死果蝇，具有比Photorhabdus和Xenorhabdus更强的胃毒活性。在侵染过程中S. nematodiphila R187激发了果蝇体内Imd和Toll两条信号途径分泌抗菌肽Drosomycin和Diptericin，Imd和Toll两条信号途径在这其同发挥重要作用。此外，S. nematodiphila R187在侵染后期逃避了果蝇免疫系统的识别从而进一步加速果蝇的死亡，但是其中具体细节还有待深入研究。25760 毕业论文关键词：昆虫病原线虫共生菌；Serraia nematodiphila R187；黑腹果蝇；胃毒活性；体液免疫 The gastric toxicity of Serraia nematodiphila R187 in the oral infection of Drosophila melanogaster Abstract：Under the background of advocating green agriculture, it is of great significance to study a new type of biological insecticides named entomopathogenic nematode-bacterial symbiont complexes. The bacterial strain Serratia nematodiphila R187, isolated from a rhabditid entomotathogenic nematode Heterorhabditidoides rugaoensis, is a highly pathogenic entomopathogenic nematode symbiotic bacterial strain and plays an essential role in the symbiotic complex of Heterorhabditidoides-Serratia. Drosophila melanogaster was used as insect target to study the gastric toxicity of S. nematodiphila R187. Results showed that S. nematodiphila R187 had stronger gastric toxicity than Photorhabdus and Xenorhabdus. The infection of S. nematodiphila R187 caused secretion of two antimicrobial peptides Drosomycin and Diptericin regulated respectively by Imd signal pathway and Toll signal pathway, which reveals the importance roles of Imd and Toll signal pathways in the resistant ability of fruit fly against oral infection of S. nematodiphila R187. In addition, S. nematodiphila R187 escaped the recognition of D. melanogaster’s immune system in the late period of infection, which resulted in the quick death of fruit flies, but more details remain to be further studied. Key words: Entomopathogenic nematodes symbiotic bacterium ; Serraia nematodiphila R187; Drosophila melanogaster ; gastric toxicity ; humoral immunity 目 录 摘要1 关键词1 Abstract1 Key words1 引言 1 1 材料与方法3 1.1 实验材料 3 1.2 实验方法 3 1.2.1 果蝇的培养繁殖3 1.2.2 共生菌对果蝇的饲喂侵染实验3 2 结果与分析4 2.1 Serratia nematodiphila R187饲喂侵染果蝇的存活率4 2.2 Serratia nematodiphila R187饲喂侵染果蝇的抗菌肽表达水平5 3 讨论 6 3.1 没有Heterorhabditidoides 类昆虫病原线虫作为载体，共生菌Serratia nematodiphila R187仍具有很强的胃毒活性6 3.2 果蝇体液免疫Imd途径和Toll途径在抵抗共生菌Serratia nematodiphila R187胃毒活性的过程中发挥了重要作用6 3.3 Serratia nematodiphila R187通过逃避果蝇免疫系统的识别来使胃毒活性产生最大化作用7 致谢7 参考文献8 Serraia nematodiphila R187饲喂侵染黑腹果蝇的胃毒活性研究 引言： 随着科学技术的发展，当今中国农业的最终走向势必是绿色农业。绿色农业的基本要求就是无毒无害无污染，这就意着防治害虫的杀虫剂以及各种农药都必须是毒性低，残留少，易降解，对周围环境没有任何污染的。生物杀虫剂就可以满足这些要求，所以近些年来，我们对新型生物杀虫剂的关注和研究越来越多。生物杀虫剂将是保障食品安全，加快落实建设绿色农业的根本途径之一[1,2]。 (责任编辑：qin) |