Fig. 4

HPT proteins in Medicago truncatula. a Number of genes encoding HPT-H (blue bars), HPT-N (red bars) and non-canonical HPTs (green bars) found in the genome of A. thaliana, M. truncatula and V. vinifera. b Phylogenetic tree of HPTs, based on full-length proteins from A. thaliana, M. truncatula and V. vinifera. Protein sequences were aligned with the Muscle algorithm and the phylogenic tree was built with the Seaview software package. Numbers indicate the probability for each branch. The tree was rooted on the HPT Ostta_34,527 from Ostreococcus tauri [75]. Blue dots indicate non-canonical HPTs. c Heat map of the expression pattern of M. truncatula genes encoding HPT proteins. Data were retrieved from the M. truncatula Gene Expression Atlas Affymetrix microarray database (MtGEA; [68]) for various organs (left panel), from [69] for roots, nodules and nodule zones (middle panels) and from [60] for root epidermis expression and response to Nod factors (NF, right panel). Meristematic zone (ZI), distal and proximal differentiation/rhizobial infection zones (ZIId and ZIIp), inter-zone (IZ) and fixation zone (ZIII). Dashes indicate that there is no probe available on the Affymetrix M. truncatula chip [68]. The red/white color scale indicates log2 expression values for each heat map, which were normalized independently, with highest expression as red and lowest expression as white. A median was used as the central value and black boxes indicate that no probe was available on the microarray