Little is known about the influence of host genotype and phytohormones on the composition of fungal endophytic communities. We investigated the influence of host genotype and phytohormones on the structure of the fungal endophytic communities of tomato roots by amplicon sequencing of the ITS1 region and combined this approach with isolation and functional characterization of the isolates. A significant effect of the host genotype on the dominant fungal species was found by comparing the cultivars Castlemart and UC82B and, surprisingly, root pathogens were among the most abundant taxa. In contrast, smaller changes in the relative abundance of the dominant species were found in mutants impaired in jasmonic acid biosynthesis (def1) and ethylene biosynthesis (8338) compared to the respective wild types. However, def1 showed significantly higher species richness compared to the wild type. Analysis of the phytohormone profiles of these genotypes indicates that changes in the phytohormone balance may contribute to this difference in species richness. Assessing the lifestyle of isolated fungi on tomato seedlings revealed the presence of both beneficial endophytes and latent pathogens in roots of asymptomatic plants, suggesting that the interactions between members of the microbiome maintain the equilibrium in the community preventing pathogens from causing disease.

中文翻译：

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通过将扩增子测序和分离方法与植物激素分析相结合，深入了解番茄真菌根内生菌的群落结构和生活方式。


关于宿主基因型和植物激素对真菌内生群落组成的影响知之甚少。我们通过 ITS1 区域的扩增子测序，研究了宿主基因型和植物激素对番茄根部真菌内生群落结构的影响，并将该方法与分离株的分离和功能表征相结合。通过比较栽培品种 Castlemart 和 UC82B，发现宿主基因型对优势真菌物种有显着影响，令人惊讶的是，根病原体是最丰富的类群之一。相反，与各自的野生型相比，茉莉酸生物合成（def1）和乙烯生物合成（8338）受损的突变体中优势物种的相对丰度变化较小。然而，与野生型相比，def1 显示出明显更高的物种丰富度。对这些基因型的植物激素谱的分析表明，植物激素平衡的变化可能导致物种丰富度的差异。评估番茄幼苗上分离的真菌的生活方式揭示了无症状植物根部中存在有益的内生菌和潜在的病原体，这表明微生物组成员之间的相互作用维持了群落的平衡，从而防止病原体引起疾病。