Mitochondrial genotyping of isolates of the arbuscular mycorrhizal fungus "Glomus intraradices" from the isolate collection of the International Bank of Glomeromycota

International audience; The culture collection of the International Bank of Glomeromycota (BEG) provides an important service to scientific community and industry by acting as a repository for well-defined AMF isolates which are made available to the public. The most widely-used species has been referred to as "Glomus intraradices", and was recently renamed Rhizophagus irregularis. This species has emerged as a model organism for experimental research and is the subject of the first AMF genome to be sequenced. The only genetic marker that can currently be used to distinguish strains of R. irregularis in field settings is the mitochondrial large subunit (mtLSU). In addition, genetically dist…

Diversity of arbuscular mycorrhizal fungi (Glomeromycota) in european soils analysed by pyrosequencing

Arbuscular mycorrhiza provides essential ecosystem functions in natural and humandominated ecosystems. Generally human activities like agriculture seem to have a negative effect on diversity of arbuscular mycorrhizal fungi (AMF), and thus on ecosystem functioning. New sequencing technologies now allow to assess AMF diversity on a much larger scale than previously. In the context of the European project EcoFINDERS, five Long-Term Observatories across Europe with different soil management have been studied. The diversity of AMF in these soils is analyzed by pyrosequencing, using the ITS (rDNA Internal Transcribed Spacers) as marker, which were recently determined as the standard barcoding gen…

RPB1 as a marker gene to analyze communities of arbuscular mycorrhizal fungi (Glomeromycota)

The influence of agricultural practice on the diversity of Arbuscular mycorrhizal fungi (AMF, Glomeromycota) continues to be an important research question as these mutualistic symbionts are known to improve plant growth and soil quality. To this day, studies of community diversity in AMF have exclusively been based on nuclear ribosomal gene regions, such as the small and large subunits and the ITS region. In the Glomeromycota, these regions show high intra-organism polymorphism, which can seriously complicate interpretation of diversity data. We chose the rpb1 gene as an alternative marker as this putative single-copy gene has been shown to be monomorphic within fungal isolates but shows a…

Molecular studies of diversity of populations of arbuscular mycorrhizal fungi

National audience; Arbuscular mycorrhiza fungi (AMF) which form a mutualistic symbiosis with most terrestrial plants are not only important for natural ecosystems, but also for agricultural production. The aim of this study is to characterize fungal populations at different geographic scales in order to better understand the processes influencing AMF taxonomic and functional diversity and to determine the environmental factors affecting AMF populations, especially in the context of agricultural management. The mitochondrial large subunit gene of ribosomal RNA will be used as molecular marker to resolve population structure of Rhizophagus irregularis (formerly known as Glomus intraradices). …

Elucidating the population structure of the ubiquitous arbuscular mycorrhizal fungal species Rhizophagus irregularis: implications for fungal community assembly

The Largest Subunit of RNA Polymerase II as a New Marker Gene to Study Assemblages of Arbuscular Mycorrhizal Fungi in the Field

Due to the potential of arbuscular mycorrhizal fungi (AMF, Glomeromycota) to improve plant growth and soil quality, the influence of agricultural practice on their diversity continues to be an important research question. Up to now studies of community diversity in AMF have exclusively been based on nuclear ribosomal gene regions, which in AMF show high intra-organism polymorphism, seriously complicating interpretation of these data. We designed specific PCR primers for 454 sequencing of a region of the largest subunit of RNA polymerase II gene, and established a new reference dataset comprising all major AMF lineages. This gene is known to be monomorphic within fungal isolates but shows an…