Muratore Melani, Sun Yvonne, Prather Chelse
Department of Biology, University of Dayton, Dayton, OH, United States.
Front Microbiol. 2020 Oct 23;11:557980. doi: 10.3389/fmicb.2020.557980. eCollection 2020.
Insect gut microbiomes consist of bacteria, fungi, and viruses that can act as mutualists to influence the health and fitness of their hosts. While much has been done to increase understanding of the effects of environmental factors that drive insect ecology, there is less understanding of the effects of environmental factors on these gut microbial communities. For example, the effect of environmental nutrients on most insect gut microbiomes is poorly defined. To address this knowledge gap, we investigated the relationship between environmental nutrients and the gut microbial communities in a small study of katydids ( = 13) of the orthopteran species collected from a costal prairie system. We sampled from unfertilized plots, as well as from plots fertilized with added nitrogen and phosphorus or sodium separately and in combination. We found significantly higher Shannon diversity for the gut bacterial communities in from plots fertilized with added sodium as compared to those collected from plots without added sodium. In contrast, diversity was significantly lower in the gut fungal communities of grasshoppers collected from plots with added nitrogen and phosphorus, as well as those with added sodium, in comparison to those with no added nutrients. There was also a strong positive correlation between the gut bacterial and gut fungal community diversity within each sample. Indicator group analysis for added sodium plots included several taxa with known salt-tolerant bacterial and fungal representatives. Therefore, despite the small sample number, these results highlight the potential for the gut bacterial and fungal constituents to respond differently to changes in environmental nutrient levels. Future studies with a larger sample size will help identify mechanistic determinants driving these changes. Based on our findings and the potential contribution of gut microbes to insect fitness and function, consideration of abiotic factors like soil nutrients along with characteristic gut microbial groups is necessary for better understanding and conservation of this important insect herbivore.
昆虫肠道微生物群由细菌、真菌和病毒组成，它们可以作为共生体影响宿主的健康和适应性。虽然在增进对驱动昆虫生态学的环境因素影响的理解方面已经做了很多工作，但对环境因素对这些肠道微生物群落的影响了解较少。例如，环境养分对大多数昆虫肠道微生物群的影响尚不明确。为了填补这一知识空白，我们在一项对从沿海草原系统采集的直翅目物种螽斯（ = 13）的小型研究中，调查了环境养分与肠道微生物群落之间的关系。我们从未施肥地块以及分别单独添加氮、磷或钠以及组合添加这些元素的施肥地块采集样本。我们发现，与从未添加钠的地块采集的样本相比，添加钠的地块中的螽斯肠道细菌群落的香农多样性显著更高。相比之下，与未添加养分的地块相比，从添加氮和磷以及添加钠的地块采集的蝗虫肠道真菌群落的多样性显著更低。每个样本中的肠道细菌和肠道真菌群落多样性之间也存在很强的正相关。添加钠地块的指示组分析包括几个具有已知耐盐细菌和真菌代表的分类群。因此，尽管样本数量较少，但这些结果凸显了肠道细菌和真菌成分对环境养分水平变化做出不同反应的潜力。未来更大样本量的研究将有助于确定驱动这些变化的机制决定因素。基于我们的研究结果以及肠道微生物对昆虫适应性和功能的潜在贡献，考虑土壤养分等非生物因素以及特征性肠道微生物群对于更好地理解和保护这种重要的食草昆虫是必要的。
