Benucci Gian Maria Niccolò, Burnard Delaney, Shepherd Lara D, Bonito Gregory, Munkacsi Andrew B
Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States.
School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand.
Front Microbiol. 2020 Jan 15;10:2944. doi: 10.3389/fmicb.2019.02944. eCollection 2019.
Lycopods are tracheophytes in the Kingdom Plantae and represent one of the oldest lineages of living vascular plants. Symbiotic interactions between these plants with fungi and bacteria, including fine root endophytes in Endogonales, have been hypothesized to have helped early diverging plant lineages colonize land. However, attempts to study the lycopod rhizobiome in its natural environment are still limited. In this study, we used Illumina amplicon sequencing to characterize fungal and bacterial diversity in nine Lycopodiaceae (club moss) species collected in New Zealand. This was done with generic fungal ITS rDNA primers, as well as Endogonales- and arbuscular mycorrhizal fungi (AMF)-selective primer sets targeting the 18S rDNA, and generic bacterial primers targeting the V4 region of the 16S rDNA. We found that the Lycopodiaceae rhizobiome was comprised of an unexpected high frequency of Basidiomycota and Ascomycota coincident with a low abundance of Endogonales and Glomerales. The distribution and abundance of Endogonales varied with host lycopod, and included a novel taxon as well as a single operational taxonomic unit (OTU) that was detected across all plant species. The Lycopodiaceae species with the greatest number and also most unique OTUs was , while the plant species that shared the most fungal OTUs were and . The bacterial OTU distribution was generally not consistent with fungal OTU distribution. For example, community dissimilarity analysis revealed strong concordance between the evolutionary histories of host plants with the fungal community but not with the bacterial community, indicating that Lycopodiaceae have evolved specific relationships with their fungal symbionts. Notably, nearly 16% of the ITS rDNA fungal diversity detected in the Lycopodiaceae rhizobiome remained poorly classified, indicating there is much plant-associated fungal diversity left to describe in New Zealand.
石松类植物是植物界中的维管植物，代表了现存维管植物中最古老的谱系之一。这些植物与真菌和细菌之间的共生相互作用，包括内囊霉目中的细根内生菌，被认为有助于早期分化的植物谱系在陆地上定殖。然而，在其自然环境中研究石松类植物根际微生物组的尝试仍然有限。在本研究中，我们使用Illumina扩增子测序来表征在新西兰采集的9种石松科（石松）植物中真菌和细菌的多样性。这是通过通用真菌ITS rDNA引物，以及靶向18S rDNA的内囊霉目和丛枝菌根真菌（AMF）选择性引物组，和靶向16S rDNA V4区域的通用细菌引物来完成的。我们发现石松科植物根际微生物组由意外高频率的担子菌门和子囊菌门组成，同时内囊霉目和球囊霉目的丰度较低。内囊霉目的分布和丰度因宿主石松类植物而异，包括一个新分类单元以及在所有植物物种中都检测到的单个可操作分类单元（OTU）。拥有最多且最独特OTU的石松科植物物种是 ，而共享最多真菌OTU的植物物种是 和 。细菌OTU分布通常与真菌OTU分布不一致。例如，群落差异分析显示宿主植物的进化历史与真菌群落之间有很强的一致性，但与细菌群落没有，这表明石松科植物与其真菌共生体已经进化出特定的关系。值得注意的是，在石松科植物根际微生物组中检测到的ITS rDNA真菌多样性中，近16%仍分类不佳，这表明在新西兰还有许多与植物相关的真菌多样性有待描述。
