Supporting information Figures S1-S5

% Supplemental figure 1 Figure S1: Mycorrhizal colonization parameter et al 1996 Mycorrhizal colonization parameters were estimated according to Trouvelot et al Data shown are average data of all three independent experiments (spring and autumn 2010 and spring 2012) +/- standard deviation.

Supplemental figure 2 Figure S2: Uptake and transport of 35 S-sulfate by Glomus intraradices. Medicago truncatula plants inoculated or not with Glomus intraradices, were grown in two- compartment systems for five weeks. 100 µCu 35 S-labeled Na-sulfate was applied to the fungal compartment and the radioactivity in the plant leaves was measured one and two days after application.

A B Supplemental figure 3 Figure S3: Phylogenetic relationship of SULTR proteins and genomic organization of SULTR gene family. (A) A Maximum-Likelihood Tree based on a Clustal W alignment was calculated using the MEGA 5.03 program (Tamura et al, 2011) with selected Sulfate Transporter Protein Sequences. Reference numbers for the corresponding nucleotide sequences are given in brackets. Arath = Arabidopsis thaliana, Mtr = Medicago truncatula. (B) Exon-intron structures of SULTR genes. The untranslated region (UTR) sequences are shown when available. Open boxes represent UTRs; solid boxes, coding regions; and solid lines, introns.

+P+Snm +P-Snm +P+Sm +P-Sm -P+Snm -P-Snm -P+Sm -P-Sm +P-Snm +P+Snm +P+Sm +P-Sm -P-Sm -P+Sm -P-Snm -P+Snm PC1: 49% PC2: 40% +P -P Supplemental Figure 4 Figure S4. PCA (Principal Component Analysis) score plot of metabolite profile. The plots were applied for contents of 27 metabolites, total soluble protein and fresh weight per plant. PC: principal component.

Supplemental Figure 5 Figure S5: Heat map representing metabolite changes per plant of mycorrhizal and non-mycorrhizal plants under different nutritional conditions. The heatmap shows the changes in the metabolite profile of M. truncatula plants under different nutritional conditions. The plants were mycorrhizal colonized (myc) or not (nm) and grown under +/- P and +/-S conditions. Metabolite contents per plant were obtained from leaf samples of 5-week-old plants. Data was normalized on the average level in all conditions. The data with log 2 scale was submitted to Hierarchical Clustering Analysis (HCA) using Pearson correlation to identify clusters of similar metabolic profiles. Cells with high abundance are presented by red colour and cells with blue colour show lower abundance with the scale above heat map.