Biosciences Division, Oak Ridge National Laboratorygrid.135519.a, Oak Ridge, Tennessee, USA.
Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA.
mSystems. 2022 Aug 30;7(4):e0012022. doi: 10.1128/msystems.00120-22. Epub 2022 Jul 18.
Pathogenic fungal infections in plants may, in some cases, lead to downstream systematic impacts on the plant metabolome and microbiome that may either alleviate or exacerbate the effects of the fungal pathogen. While Sphaerulina musiva is a well-characterized fungal pathogen which infects tree species, an important wood fiber and biofuel feedstock, little is known about its systematic effects on the metabolome and microbiome of . Here, we investigated the metabolome of Populus trichocarpa and Populus deltoides leaves and roots and the microbiome of the leaf and root endospheres, phylloplane, and rhizosphere to understand the systematic impacts of abundance and infection on species in a common garden field setting. We found that is indeed present in both and , but abundance was not statistically related to stem canker onset. We also found that the leaf and root metabolomes significantly differ between the two species and that certain leaf metabolites, particularly the phenolic glycosides salirepin and salireposide, are diminished in canker-infected trees compared to their uninfected counterparts. Furthermore, we found significant associations between the metabolome, abundance, and microbiome composition and α-diversity, particularly in leaves. Our results show that colonizes both resistant and susceptible hosts and that the effects of on susceptible trees are not confined to the site of canker infection. Poplar ( spp.) trees are ecologically and economically important trees throughout North America. However, many western North American poplar plantations are at risk due to the introduction of the nonnative fungal pathogen , which causes leaf spot and cankers, limiting their production. To better understand the interactions among the pathogen , the poplar metabolome, and the poplar microbiome, we collected leaf, root, and rhizosphere samples from poplar trees consisting of 10 genotypes and two species with differential resistance to in a common garden experiment. Here, we outline the nuanced relationships between the poplar metabolome, microbiome, and , showing that may affect poplar trees in tissues distal to the site of infection (i.e., stem). Our research contributes to improving the fundamental understanding of and sp. ecology and the utility of a holobiont approach in understanding plant disease.
植物病原真菌感染在某些情况下可能会对植物代谢组和微生物组产生下游系统影响，这些影响既可能减轻也可能加剧真菌病原体的影响。虽然 Sphaerulina musiva 是一种已被充分研究的真菌病原体，可感染树种，这些树种是重要的木材纤维和生物燃料原料，但对于其对 的代谢组和微生物组的系统影响知之甚少。在这里，我们研究了毛白杨和三角杨的叶片和根部的代谢组以及叶片和根部的内球体、叶表面和根际的微生物组，以了解 在常见的田间环境中丰度和感染对物种的系统影响。我们发现 确实存在于 和 中，但 丰度与茎溃疡病的发生没有统计学上的关系。我们还发现，两种 物种的叶片和根部代谢组存在显著差异，并且在感染溃疡病的 树木中，某些叶片代谢物，特别是酚糖苷 Salirepin 和 Salireposide，比未感染的对应物减少。此外，我们发现代谢组、 丰度和微生物组组成和 α 多样性之间存在显著关联，特别是在 叶片中。我们的研究结果表明， 定植于抗性和敏感性宿主，并且 对敏感性树木的影响不仅限于溃疡感染部位。杨属（ spp.）树种是北美具有生态和经济重要性的树种。然而，由于非本地真菌病原体 的引入，许多北美西部的杨树苗圃面临风险，该病原体可引起叶斑和溃疡，限制其产量。为了更好地理解病原体 、杨属代谢组和杨属微生物组之间的相互作用，我们从由 10 个基因型和两个对 具有不同抗性的物种组成的杨属树木中收集了叶片、根部和根际样本，进行了一个共同田间实验。在这里，我们概述了杨属代谢组、微生物组和 之间的细微关系，表明 可能会影响感染部位以外的组织中的杨属树木（即茎）。我们的研究有助于提高对 和 生态的基本理解，并提高整体生物组方法在理解植物疾病方面的实用性。
