Endophyte infection influences arbuscular mycorrhizal fungi communities in rhizosphere soils of host as opposed to non‐host grass

Abstract

Endophytes live asymptomatically within many cool‐season grasses for at least a portion of their life cycle. Although the leaf endophyte effects on the growth and stress resistance of host grasses have been relatively well studied, less attention has been focused on how this relationship may impact soil microbial communities, especially arbuscular mycorrhizal fungi (AMF). We defined endophyte‐infected and endophyte‐free Leymus chinensis as the host grass and neighbouring Stipa krylovii, which was not infected by endophytes, as the non‐host grass. Our objective was to examine the effect of endophyte infection on the colonization rate and composition of AMF communities in both the rhizosphere and bulk soils of their host (L. chinensis) and a neighbouring non‐host (S. krylovii) by a consecutive 2‐year survey. We described AMF communities using high‐throughput DNA sequencing, quantified the proportion of root length colonized by AMF using microscopy, and estimated AMF biomass using a lipid biomarker. Structural equation modelling (SEM) was applied to disentangle the direct and indirect effects (mediated by multiple environmental factors) of an endophyte on AMF. We found that endophyte infection significantly increased colonization rates and rhizosphere soil biomass of AMF but had no significant effect on the bulk soil around the host grass. The endophyte increased the diversity of the rhizosphere soil AMF community by decreasing the abundance of the dominant species Glomus while increasing the abundance of some unidentified AMF. SEM showed that the endophyte effects on AMF biomass in rhizosphere soil were primarily mediated by soil total carbon, total nitrogen and pH. With respect to the non‐host grass, the endophyte infection of host grass did not change the colonization rates or AMF biomass in either the rhizosphere or bulk soil but did cause a shift in the rhizosphere soil AMF community composition, resulting in a decrease in the relative abundance of Septoglomus and an increase in the relative abundance of some unidentified AMF. Highlights Effects of endophyte infection on AMF communities in both the rhizosphere and bulk soils were studied. Endophyte effect was studied not only on the host but also on the non‐host grass. Endophyte infection significantly increased colonization rates and rhizosphere soil biomass of AMF. Endophyte effect on AMF biomass in rhizosphere soil was primarily mediated by soil physicochemical properties.

The microbiota diversity of Festuca sinensis seeds in Qinghai-Tibet Plateau and their relationship with environments

“…However, there are relatively few reports on the effects of Epichloë endophytes on microbial communities, and research results are inconsistent. One study suggested that Epichloë endophytes can affect the microbial diversity in the roots and rhizosphere (Liu et al, 2021 ). Another study has reported that E. festucae var.…”

Soil fungal and bacterial communities are altered by the incorporation of leaf litter containing a fungal endophyte

“…Epichloë endophytes can affect nutrient cycling and alter soil physicochemical properties (Guo et al, 2016). Extensive studies have shown that changes in soil nutrients can alter the diversity and composition of microbial communities in plant root systems and soil (Liu et al, 2015(Liu et al, , 2020. The effect of Epichloë endophytes of grasses on soil chemistry and microbial community varies depending on host species, endophyte genetics, soil type and experimental treatments (Casas et al, 2011;Jenkins et al, 2006;Larimer et al, 2012;Rojas et al, 2016).…”

Epichloë endophyte interacts with saline-alkali stress to alter root phosphorus-solubilizing fungal and bacterial communities in tall fescue

“…These root-associated microorganisms promote plant growth through root-hair proliferation, enhancing soil fertility; increase in nitrogen fixation ability; enhanced leaf surface area; improvement in vigor and biomass; increased indigenous plant hormones levels; and most importantly, by improving nutrient use efficiency (Fan et al, 2020;Singh R. K. et al, 2022). The most studied microorganisms that are affected by the Epichloë endophytes are AMF, and the results have shown that Epichloë endophytes can change the colonization, diversity and community of AMF (Vignale et al, 2016;Liu et al, 2020Liu et al, , 2022aTerlizzi et al, 2022).…”

“…In the grass- Epichloë endophytes symbiotic relationship, the grass provides the endophytes with nutrients and shelter, and in exchange, the endophytes promote grass growth and confer protection against abiotic such as drought and saline-alkali and biotic such as herbivores and foliar pathogens stressors ( Chen et al, 2017 ; Liu et al, 2017 , 2022a ; Qin et al, 2019 ; Li et al, 2020 ; Yang et al, 2020 ). Although the consequences of Epichloë endophyte infection on the growth and resistance of host grasses have been well documented, to our knowledge, only a few papers have measured the impact of aboveground Epichloë endophytes on belowground components, especially on microorganisms ( Arrieta et al, 2015 ; Vignale et al, 2016 ; Zhong et al, 2018 ; Liu et al, 2020 , 2022b ; Mahmud K. et al, 2021 ).…”

“…A. et al, 2021 ; Singh R. K. et al, 2022 ). The most studied microorganisms that are affected by the Epichloë endophytes are AMF, and the results have shown that Epichloë endophytes can change the colonization, diversity and community of AMF ( Vignale et al, 2016 ; Liu et al, 2020 , 2022a , b ; Terlizzi et al, 2022 ).…”