Abstract Detail

Recent Topics Posters

Beaudet, Denis [1], Dalpé, Yolande [2], Corradi, Nicolas [1].

Single Cell Transcriptomics: a novel approach to better understand the endomycorrhizae symbiosis evolution.

Arbuscular mycorrhizal fungi (AMF) are a group of ecologically and economically important organisms establishing a symbiotic relationship with more than 80% of plant species. These fungi are members of the Glomeromycota phylum for which the earliest fossils date back from 450M years ago. They are notoriously challenging to study, given their obligtate biotrophic nature, i.e. they cannot grow without the presence of a host plant. Only a few species are able to thrive in axenic in vitro conditions with Agrobacterium transformed hairy roots as the symbiotic partner. This situation is reminiscent of the 'great plate count anomaly’ in microbiology, where most of the bacterial biodiversity in an environmental sample is not represented on the Petri dish in laboratory conditions. To alleviate this problem, most of the available AMF collection strains are maintained with whole plants in greenhouses pot cultures. However, the quality and quantity of the biological material recovered from these systems and the presence of contamination are a limiting factor for conventional downstream genomic and transcriptomic Next Generation Sequencing (NGS) analysis. Recently, the complete transcriptome and nuclear genome of the model AMF species Rhizophagus irregularis have become publicly available, offering the first building blocks to better understand their genome organization, plasticity and most importantly, their functional diversity. Even with the milestone represented by such reference data sets, it is crucial to obtain insights into a broader range of distantly related AMF taxa, to improve our knowledge regarding the evolution of this ancient fungal phylum, its phylogenetic affiliation and the characterisation of the functional diversity playing a role in the symbiosis establishment. To assess this need and to overcome the challenges stated above, we used an approach widely used in medical research, single cell transcriptomic (SCT). Advances in high-throughput sequencing technology make it now possible to obtain information on single-cell transcriptomes at high level of resolution by RNA sequencing analysis. To generate transcriptomes using minute amounts of AMF material, whole spores lysate is reverse-transcribed using oligo(dT) primers, which leaves out bacterial contamination, to convert mRNAs with poly(A) tails into first-strand cDNAs. The resulting cDNAs are uniformly amplified with universal oligo(dT) primers. The resulting libraries obtained from representatives of divergent AMF genera, such as Funneliformis, Paraglomus, Ambispora, Archaeospora, Acaulospora, Diversispora, Dentiscutata, Entrophospora and Scutellospora, will be further sequenced using paired-end Illumina. The SCT approach represents a promising avenue to overcome long lasting obstacles in AMF research.

1 - University of Ottawa, Biology, 30 Marie-Curie private, Ottawa, ON, K1N6N5, Canada
2 - Agriculture and Agrifood Canada, 960 Carling avenue, Ottawa, ON, K1A0C6, Canada

Keywords:
arbuscular mycorrhizal fungi
symbiosis
Single Cell Transcriptomics
Transcriptome
gene expression
Phylogenomic.

Presentation Type: Recent Topics Poster
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PRT008
Abstract ID:1786
Candidate for Awards:None