PDF(Pubmed)
Abstract：
The pine wood nematode (PWN) uses several Monochamus species as vehicles, through a temporary hitchhiking process known as phoresy, enabling it to access new host plant resources. Monochamus saltuarius acts as a new and major vector of the PWN in Northeastern China, showing lower PWN carrying capacity and a shorter transmission cycle compared to established vectors. The apparently altered symbiotic relationship offers an interesting area for researching the costs and adaptions involved in nematode-beetle, a specialized phoresy. We analyzed the response and fitness costs of M. saltuarius through physiological measurements and transcriptomics. The PWN exerted adverse repercussions on the growth and development of M. saltuarius. The PWN accelerated larval development into pupae, while beetle adults carrying the PWN exhibited an elevated abnormality rate and mortality, and reduced starvation resistance. During the pupal stage, the expression of growth-related genes, including ecdysone-inducible genes (E74EA), cuticle proteins, and chitin genes (CHTs), markedly increased. Meanwhile, the induced immune response, mainly by the IMD and Toll signaling pathways, could be a contributing factor to adult abnormality and mortality. Adult gonads and trachea exhibited enrichment in pathways related to fatty acid elongation, biosynthesis, and metabolism. FASN, ELOVL, and SCD possibly contributed to resistance against PWN. Our research indicated that phoretic interactions between vector beetles and PWN vary throughout the vector\'s lifespan, particularly before and after entry into the trachea. This study highlighted the fitness costs of immunity and metabolism on the vector beetle, indicating the adaptation mechanisms and evolutionary trade-offs to PWN.
摘要：
松木线虫（PWN）使用几种Monochamus物种作为载体，通过一个叫做pheresy的临时搭便车过程，使其能够访问新的宿主植物资源。土豆菜是中国东北地区PWN的新载体和主要载体，与已建立的矢量相比，显示出较低的PWN承载能力和较短的传输周期。明显改变的共生关系为研究线虫-甲虫的成本和适应性提供了一个有趣的领域，专门的eresy。我们通过生理测量和转录组学分析了盐曲霉的反应和健身成本。PWN对盐藻的生长发育产生不利影响。PWN加速幼虫发育成蛹，而携带PWN的甲虫成虫表现出升高的异常率和死亡率，并降低了对饥饿的抵抗力。在蛹期,生长相关基因的表达，包括蜕皮激素诱导基因（E74EA），角质层蛋白质，和几丁质基因（CHTs），明显增加。同时,诱导的免疫反应，主要通过IMD和Toll信号通路，可能是成人异常和死亡率的一个因素。成年性腺和气管在与脂肪酸伸长相关的途径中表现出富集，生物合成，和新陈代谢。FASN,ELOVL,和SCD可能有助于抵抗PWN。我们的研究表明，载体甲虫和PWN之间的电泳相互作用在整个载体的寿命内变化，特别是在进入气管之前和之后。这项研究强调了矢量甲虫的免疫和新陈代谢的健身成本，表明了PWN的适应机制和进化权衡。
