The Microbiome of the Medicinal Plants Achillea millefolium L. and Hamamelis virginiana L.

Abstract

In the recent past many studies investigated the microbiome of plants including several medicinal plants (MP). Microbial communities of the associated soil, rhizosphere and the above-ground organs were included, but there is still limited information on their seasonal development, and in particular simultaneous investigations of different plant organs are lacking. Many studies predominantly addressed either the prokaryotic or fungal microbiome. A distinction of epi- and endophytic communities of above-ground plant organs has rarely been made. Therefore, we conducted a comprehensive investigation of the bacterial and fungal microbiome of the MP Achillea millefolium and studied the epi- and endophytic microbial communities of leaves, flower buds and flowers between spring and summer together with the microbiome of the associated soil at one location. Further, we assessed the core microbiome of Achillea from four different locations at distances up to 250 km in southern Germany and Switzerland. In addition, the bacterial and fungal epi- and endophytic leaf microbiome of the arborescent shrub Hamamelis virginiana and the associated soil was investigated at one location. The results show a generally decreasing diversity of both microbial communities from soil to flower of Achillea. The diversity of the bacterial and fungal endophytic leaf communities of Achillea increased from April to July, whereas that of the epiphytic leaf communities decreased. In contrast, the diversity of the fungal communities of both leaf compartments and that of epiphytic bacteria of Hamamelis increased over time indicating plant-specific differences in the temporal development of microbial communities. Both MPs exhibited distinct microbial communities with plant-specific but also common taxa. The core taxa of Achillea constituted a lower fraction of the total number of taxa than of the total abundance of taxa. The results of our study provide a basis to link interactions of the microbiome with their host plant in relation to the production of bioactive compounds.

Fungal microbiome shifts on avocado fruit associated with a combination of postharvest chemical and physical interventions

“…Another core taxon observed in both the fructoplane and SE pulp of ‘Hass’ avocado, R. mucilaginosa , was previously reported to promote plant growth and seed germination in a bioassay using Brassica juncea (Ramos‐Garza et al, 2015). We further observed that there was a decrease in numbers of core taxa from the epiphytic (16) to endophytic (6) compartments of the ‘Hass’ avocado fruit and this is similar to the findings of Sauer et al (2021) on Achillea leaves. Despite not being dominant in the SE pulp at all of the six avocado postharvest stages in the present study, the potential SER‐causing genera, Neofussicocum , Fusarium , Penicillium and Epicoccum were all present in very high abundances at the ripe and ready‐to‐eat stage, which is a critical point in pathogen infection.…”

“…Amongst these core taxa were members of the Ascomycota phylum including Cladosporium, Neofussicocum, Fusarium, Penicillium and Epicoccum, which were previously described as SER causing genera in avocado (Fourie & Coertzen, 2018;Valencia et al, 2019;Wanjiku et al, 2021). The core communities tend to be comprised of key microbial taxa that play an essential role in the health and fitness of the plant holobiont (Lemanceau et al, 2017;Sauer et al, 2021),…”

“…Other fungal phyla not reported to be prevalent on avocado such as Mucoromycotina were also detected in the present study. Microbial core communities of plants have so far been rarely investigated (Sauer et al, 2021) and for the first time, the current study endeavoured to distinguish the epi‐ and endophytic core communities of avocado fruit at the postharvest stage. Our ‘Hass’ avocado core taxa analysis revealed 16 fungal taxa that were conserved on the fructoplane (epiphyte) of the fruit across the six different postharvest stages.…”

“…Amongst these core taxa were members of the Ascomycota phylum including Cladosporium , Neofussicocum , Fusarium , Penicillium and Epicoccum , which were previously described as SER causing genera in avocado (Fourie & Coertzen, 2018; Valencia et al, 2019; Wanjiku et al, 2021). The core communities tend to be comprised of key microbial taxa that play an essential role in the health and fitness of the plant holobiont (Lemanceau et al, 2017; Sauer et al, 2021), for example, they provide critical ecological functions such as protection of the host from pathogen attack (Ramos‐Garza et al, 2015). Supporting this, we observed three core taxa in very high abundances, including two Ascomycota genera Meyerozyma and Aureobasidium and one Basidiomycota genera, Papiliotrema , which have been reported to have biocontrol effect against plant pathogens (Agirman & Erten, 2020; Schisler et al, 2019).…”

Assembly, Core Microbiota, and Function of the Rhizosphere Soil and Bark Microbiota in Eucommia ulmoides

“…The microbiota of medicinal plants is an important factor affecting the health and productivity of the host ( Maggini et al, 2020 ), and can be directly or indirectly involved in the production of biologically active compounds by the host ( Koberl et al, 2013 ). The medicinal plant-associated microbiota has been gradually characterized with the omics technology ( Chen et al, 2018 ; Ulloa-Muñoz et al, 2020 ; Dong et al, 2021c ; Sauer et al, 2021 ). However, the mechanism of medicinal plant-associated microbiota construction and the phenotype and function of the core microbiota have yet to be elucidated.…”