show Abstracthide AbstractPurpose: We here wanted to describe the gene regulation of Gigaspora rosea in association with phyllogenetically divergent plant hosts, and compare these results with gene regulation occuring in R. irregularis, the model arbuscular mycorrhizal fungus. Methods: mRNA from Medicago truncatula (legume), Brachypodium distachyon (grass) in association with G. rosea, and extra radical mycelium of G.rosea were sequenced by Illumina. Reads were mapped on a in-house de novo transcript assembly with the software CLC workbench. Fungal gene expression in the different host plants was compared to extra radical hyphae as reference. Results: Sets of 1891 and 1566 G. rosea genes were highly overexpressed (fold change >5 ; FDR <0,05 and experimental value difference > 10) , in M. truncatula and B. distachyon respectively compared to ERM, among which 802 of them were up-regulated in both plants. Non common up-regulated genes are mainly found non statistically robust in one condition. Conclusions: Our study represents the first transcriptomic analysis on several hosts for this fungal species. These results showed that the interaction between plants and AMF is highly conserved. Overall design: Extra radical and intra radical hyphae in association with 2 phylogenetically divergent plants were produced and gene expression in the different plants were compared to gene expression in extra radical hyphae.