Vascular tissues, xylem and phloem, are defining features of vascular plants and are predicted to have been key innovations during land plant evolution. However, it is unclear when the genetic toolkits of these tissues evolved especially the phloem. More data about the structural development and gene expression in seed-free plants will help us characterise the origin of the phloem genetic toolkit and test the homology between different food-conduction cells, including phloem sieve elements in different tracheophytes. Some key proteins are described to regulate different stages of development of the phloem in Arabidopsis. The membrane protein OCTOPUS (OPS) is present in procambial cells that give rise to sieve elements, although the mechanism by which it acts is unknown. The transcription factor ALTERED PHLOEM DEVELOPMENT (APL) is expressed in protophloem poles and upregulates NAC45 and NAC86, which trigger the dissolution of nuclei and cytoplasmic organelles in sieve elements. These three groups of genes are major upstream regulators of the sieve cell development in angiosperms. The activity of orthologues of these proteins in other groups of plants is largely unknown, especially in seed-free plants. If they are present and expressed similarly in angiosperms and lycophytes, this would indicate that this is the genetic tool kit used by the common ancestor of tracheophytes during the development of their phloem. Moreover, the presence of these genes in bryophytes would shed light on the question of the homology of food-conducting tissues present in all land plants. We investigated the evolution of homologs of OPS, APL, and NAC45/86 in land plants. To do this, we searched for homologs in genomes and transcriptomes, with a good representation of the phylogenetic diversity of tracheophytes and bryophytes. Phylogenetic trees were obtained from aligned nucleotide sequences partitioned by codon position, through the maximum likelihood method. The orthologues of these proteins are present in all major lineages of tracheophytes, revealing that they were likely to be present in their common ancestor. Currently, we are working on RNA in-situ hybridization experiments in the model lycophytes Selaginella moellendorffii to detect if it is expressed in comparable cell types and stages considering what is known for Arabidopsis.