This dataset supports the data presented in the following PhD thesis: "Evolutionary conservation of host responses to arbuscular mycorrhizal symbiosis in liverworts" submitted by Mara Sgroi for the Degree of Doctor in Philosophy in March 2021. The detailed methods used to generate each supplementary file are described in detail in the Methods Chapter of the associated thesis record. This dataset comprises of: (Supplementary Table 1) Results of differential expression analysis of RNA-seq data from M. paleacea thalli colonized by Rhizophagus irregularis after 5, 8, or 11 weeks post inoculation or after treatment with R. irregularis germinated spore exudates; (Supplementary Table 2) GO enrichment analysis of differentially expressed genes during M. paleacea arbuscular mycorrhizal symbiosis; (Supplementary Table 3) List of genomic resources used as input for orthology inference analysis of 20 land plant genomes and 2 green algae genomes with the Orthofinder analysis pipeline; (Supplementary Table 4) table of transcript IDs belonging to each orthogroup identified by the Orthofinder analysis pipeline; (Supplementary table 5) list of Medicago truncatula direct orthologs of M. paleacea transcripts identified with the Orthofinder analysis pipeline; (Supplementary table 6) M. paleacea and M. truncatula orthologs significantly differentially expressed (RNAseq) during arbuscular mycorrhizal symbiosis; (Supplementary table 7) Amino-acid sequences of candidate M. paleacea pathogenesis-related and gibberellic acid biosynthetic genes, with corresponding M. polymorpha orthologs; (Supplementary File 1) transcript sequences of the Marchantia paleacea transcriptome assembled for the RNAseq analysis of M. paleacea thalli colonized by the arbuscular mycorrhizal fungus Rhizophagus irregularis and in non-colonized conditions. The transcriptome was assembled by combining RNAseq reads from 3 time points for the inoculated and the non-inoculated condition which were collected respectively at 5, 8 and 11 weeks post-inoculation with the fungus and the combined RNAseq reads of M. paleacea thalli treated with germinated spore exudates of R. irregularis or mock-treated; (Supplementary File 2) the predicted peptide sequences of the M. paleacea transcriptome, which were predicted and translated in silico using TransDecoder; (Supplementary File 3) the resolved, unannotated, phylogenetic trees of each orthogroup identified by orthology inference (Orthofinder2) analysis across 20 land plant genomes and 2 green algae;