Home • Rhizophagus irregularis DAOM 197198 v2.0
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Carrot roots colonized by R. irregularis DAOM197198 mycelium
Image credit : Guillaume Bécard

The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but this genomic organization has been questioned.


Rhizophagus irregularis DAOM197198

In 2013, we have published the haploid genome of Rhizophagus irregularis DAOM197198 and its repertoire of 28,232 genes. The observed low level of genome polymorphism is not consistent with the occurrence of multiple, highly diverged genomes. The expansion of mating-related genes suggests the existence of cryptic sex-related processes. A comparison of gene categories confirms that R. irregularis is close to the Mucoromycotina. The AMF obligate biotrophy is not explained by genome erosion or any related loss of metabolic complexity in central metabolism, but is marked by a lack of genes encoding plant cell wall degrading enzymes and of genes involved in toxin and thiamine synthesis. A battery of mycorrhiza-induced secreted proteins is expressed in symbiotic tissues.

The initial genome sequence assembly from R. irregularis DAOM197198 was highly fragmented with 28,371scaffolds. The genome sequence was therefore re-sequenced on the Illumina HiSeq2500 using 3kb- and 8kb-mate pair Nextera libraries and one paire-end (2 x 125 bp) TruSeq Nano library on early 2015. The genome sequence was assembled with ALLPATHS-LG and the novel assembly contains 1123 scaffolds only. The JGI Annotation Pipeline predicted 25,930 genes.

The Mycorrhizal Genomics Initiative is a large collaborative effort aiming for master publication(s) describing the evolution of the mycorrhizal symbioses. Researchers who wish to publish analyses using data from unpublished MGI genomes are respectfully required to contact the PIs and JGI to avoid potential conflicts on data use and coordinate other publications with the MGI master paper(s).

Please cite the following publication(s) if you use the data from this genome in your research: 

Tisserant E, Malbreil M, Kuo A, Kohler A, Symeonidi A, Balestrini R, Charron P, Duensing N, Frei dit Frey N, Gianinazzi-Pearson V, Gilbert LB, Handa Y, Herr JR, Hijri M, Koul R, Kawaguchi M, Krajinski F, Lammers PJ, Masclaux FG, Murat C, Morin E, Ndikumana S, Pagni M, Petitpierre D, Requena N, Rosikiewicz P, Riley R, Saito K, San Clemente H, Shapiro H, van Tuinen D, Becard G, Bonfante P, Paszkowski U, Shachar-Hill YY, Tuskan GA, Young JP, Sanders IR, Henrissat B, Rensing SA, Grigoriev IV, Corradi N, Roux C, Martin F (2013) Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis.Proc Natl Acad Sci USA 110: 20117-20122. doi: 10.1073/pnas.1313452110.

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