Distinct identities of leaf phloem cells revealed by single cell transcriptomics

Abstract The leaf vasculature plays a key role in solute translocation. Veins consist of at least seven distinct cell types, with specific roles transport, metabolism, and signaling. Little is known about vascular cells, particular the phloem parenchyma (PP). PP effluxes sucrose into apoplasm as basis for loading, yet has been characterized only microscopically. Here, we enriched cells from Arabidopsis leaves to generate single-cell transcriptome atlas vasculature. We identified 19 clusters, encompassing epidermis, guard hydathodes, mesophyll, all used metabolic pathway analysis define their roles. Clusters comprising were transporters, including SWEET11 SWEET12 UmamiT amino acid efflux carriers. provide evidence that development occurs independently ALTERED PHLOEM DEVELOPMENT, transcription factor required differentiation. have unique pattern metabolism activity companion (CCs), explaining differential distribution/metabolism acids veins. kinship relation clusters strikingly similar vein morphology, except clear separation CC other PP. In summary, our RNA-sequencing provides wide range information relationship types.