Agricultural land‐use favours Mucoromycotinian, but not Glomeromycotinian, arbuscular mycorrhizal fungi across ten biomes

Abstract

Globally, agricultural land-use negatively affects soil biota that contribute to ecosystem functions such as nutrient cycling, yet arbuscular mycorrhizal fungi (AMF) are promoted as essential components of agroecosystems. Arbuscular mycorrhizal fungi include Glomeromycotinian AMF (G-AMF) and the arbuscule-producing fine root endophytes, recently reclassified into the Endogonales order within Mucoromycotina. The correct classification of Mucoromycotinian AMF (M-AMF) and the availability of new molecular tools can guide research to better the understanding of their diversity and ecology.To investigate the impact on G-AMF and M-AMF of agricultural land-use at a continental scale, we sampled DNA from paired farm and native sites across 10 Australian biomes.Glomeromycotinian AMF were present in both native and farm sites in all biomes. Putative M-AMF were favoured by farm sites, rare or absent in native sites, and almost entirely absent in tropical biomes. Temperature, rainfall, and soil pH were strong drivers of richness and community composition of both groups, and plant richness was an important mediator.Both fungal groups occupy different, but overlapping, ecological niches, with M-AMF thriving in temperate agricultural landscapes. Our findings invite exploration of the origin and spread of M-AMF and continued efforts to resolve the phylogeny of this newly reclassified group of AMF.

Diversity and Ecological Guild Analysis of the Oil Palm Fungal Microbiome Across Root, Rhizosphere, and Soil Compartments

“…Glomeromycotina sequences were detected in the root compartment of oil palm in all plantations, suggesting the presence of the arbuscular symbiosis within palm roots. Currently, M-AMF forming the fine root endophyte arbuscular morphology has been linked to a small clade within the Endogolales, centered on OTU0 and OTU4 from Orchard et al (2017), the latter showing 100% sequence match to the only described species of M-AMF fine root endophyte, Planticonsortium tenue (Albornoz et al, 2021). Albornoz et al (2020a,b) found FRE colonization in 44 of 58 Australian pastures sampled, and 92% of the associated Mucoromycotinian sequences clustered within this clade, with 74% of sequences belonging to three OTUs which were distinct from both OTU0 and 4.…”

“…Overall the evidence suggests that M-AMF were not present on oil palm roots. In a study of Australian biomes, Albornoz et al (2021) found that across 10 Australian biomes putative M-AMF were favored by agricultural land use, were rare or absent in native ecosystems, but were not found in tropical biomes.…”

“…Phylogenetic analysis of Mucoromycotina 18S rRNA gene sequences was performed to investigate relatedness to taxa which are considered to form the fine root endophyte arbuscular symbiosis. Reference sequences of putative Mucoromycotinian arbuscular mycorrhizal fungi (M-AMF) were obtained from Orchard et al (2017) and Albornoz et al (2021), and these were supplemented with a broad range of Mucoromycotinian sequences which encompassed the known biodiversity within this group. Sequence alignments were generated with the MUSCLE alignment tool using default parameters (Edgar, 2004).…”

The potential role of Mucoromycotina ‘fine root endophytes’ in plant nitrogen nutrition

“…MFRE have a wide distribution across plant lineages and ecosystem types, from lycophytes in European heathlands (Kowal et al, 2020) to legumes in Australian pastures (Albornoz et al, 2021), with a potentially prominent role in host plant N nutrition (Field et al, 2019). Because of this, as well as experimental possibilities opened up by isolation and axenic culture experiments, future research into MFRE promises exciting new insights into plant N acquisition both at individual, community, and potentially even agricultural (Albornoz et al, 2022) levels. How this fits mechanistically and ecologically with other forms of mycorrhizas, involving both saprotrophic and obligately biotrophic fungi, is a key area for further study that can be facilitated by new molecular and bioinformatic tools.…”

Atmospheric pollution, soil nutrients and climate effects on Mucoromycota arbuscular mycorrhizal fungi

“…In that study, pH had the strongest effect on the diversity of fungi. This finding is also consistent with Albornoz et al (2022) which found M-AMF preference for acidic soils across a wide sampling of agricultural sites in Australia. Still, more studies have focused on G-AMF ecological requirements, without differentiating M-AMF.…”