Establishment and maintenance of vascular cell communities through local signaling

During plant development, cell fates are often determined by cell-to-cell communication. The vascular system, in which procambial/cambial cells continue to provide cells to two conductive tissues, xylem and phloem, is an excellent model for understanding cell-to-cell communication as a developmental cue. Recent studies on vascular development have revealed several novel intercellular signaling molecules that regulate vascular cell fates by unique mechanisms. This review focuses on emerging novel concepts such that reciprocal signaling by a transcription factor and microRNAs between the stele and the endodermis determines xylem cell patterns, and that a small peptide secreted from phloem governs vascular stem-cell maintenance.

Research highlights▶ Reciprocal signaling by SHR and miR165/6 regulates root vascular tissue patterning. ▶ The TDIF signal from phloem contributes to vascular stem-cell maintenance. ▶ Some CLE peptides affect root protoxylem vessel formation via cytokinin signaling.