松墨天牛肠道共生细菌的多样性及其在松材线虫侵染循环中的功能研究

项目名称： 松墨天牛肠道共生细菌的多样性及其在松材线虫侵染循环中的功能研究

项目编号： No.31470650

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 农业科学

项目作者： 郝德君

作者单位： 南京林业大学

项目金额： 85万元

中文摘要： 昆虫在长期协同进化过程中与肠道细菌相互选择，相互适应，形成了密切的共生关系。本项目以松墨天牛肠道共生细菌为研究对象，采用昆虫解剖学、昆虫生理学、微生物学、分子生物学、生物信息学、统计学等原理和方法，研究松墨天牛幼虫、蛹和成虫的肠道共生细菌组成和群落结构，进而测定分析与不同虫态偶联的松材线虫及寄主植物的蛀道、蛹室及取食和产卵部位的细菌群落特征，探明松材线虫共生菌来源及其与松墨天牛肠道共生细菌组成和群落结构的相关性；分离、筛选具有分解纤维素和降解树脂萜类的优势菌，验证其对纤维素和单萜、二萜的分解能力，阐释肠道共生细菌对松墨天牛的营养作用和松材线虫抵御寄主化学防御的功能；通过生物测定天牛肠道共生细菌和树脂萜类对松材线虫转型发育，繁殖的协同作用，探究松墨天牛肠道共生菌在松材线虫与媒介昆虫互作中的作用，为进一步以媒介昆虫的肠道共生细菌为切入点探讨和揭示松材线虫的传播扩散机制和致病机理提供理论依据。

中文关键词： 松墨天牛；肠道共生菌；群落结构；宏基因组

英文摘要： Insects construct various symbiotic relationships with a wide diversity of microorganisms during their co-evolution, and gut bacteria are specially proved to confer a variety of benifits to the host, such as direct or indirect nutrition, assistance in overcoming host defenses, protection from natural enemies, improved development and reproduction, and communication. Based on our previous research accumulations and by means of Entomotomy, Entomological physiology, Microbiology, Molecular biology, Bioinformatics and Biostatistics techniques, the purpose of this research was to characterize the gut bacterial communities associated with the pine sawyer beetle Monochamus alternatus. We will examinefourth-instar larvae, pupae, and newly emerged adults using both culture-based and culture-independent methods. We also want to make comparisons among fore-, mid-, and hindguts of selected beetles and environmentally derived samples to identify and distinguish bacterial taxa that are transmitted from the adult to larval and pupae stages. By identifying and comparing bacterial community members among different life stages of the insect and with bacteria it encounters in the environment to determine the source of the bacterial community harbored by Bursaphelenchus xylophilus.Through megagenome sequencing we compile a suite of candidate genes found in the gut bacteria community whose annotations are consistent with cellulose-degrading capabilities and other genes that have roles in nutrient synthesis and detoxification. Additionally, we isolate and identify dominant cellulose-degrading bacteria and terpene-detoxificating bacteria and test their nutritional and metabolic potential to host insect. Finally we will separately and jointly examine gut bacteria and terpenes influences on survival, development and reproduction of B. Xylophilus, so as to confirm their prominent functions on interaction between M. Alternatus and B. Xylophilus. These results are crucial to focus future research on particular bacterial species and functional gene that are more likely to be of critical importance to the insect and may help explore transmission and pathogenic mechanism of this plant-parasitic nematode.

英文关键词： monochamus alternatus;gut bacterial;community strcture;Metagenome