title: Non-cell-autonomous control of vascular stem cell fate by a CLE peptide/receptor system.
abstract: Land plants evolved a long-distance transport system of water and nutrients composed of the xylem and phloem, both of which are generated from the procambium- and cambium-comprising vascular stem cells. However, little is known about the molecular mechanism of cell communication governing xylem-phloem patterning. Here, we show that a dodecapeptide (HEVHypSGHypNPISN; Hyp, 4-hydroxyproline), TDIF (tracheary element differentiation inhibitory factor), is secreted from the phloem and suppresses the differentiation of vascular stem cells into xylem cells through a leucine-rich repeat receptor-like kinase (LRR-RLK). TDIF binds in vitro specifically to the LRR-RLK, designated TDR (putative TDIF receptor), whose expression is restricted to procambial cells. However, the combined analysis of TDIF with a specific antibody and the expression profiles of the promoters of two genes encoding TDIF revealed that TDIF is synthesized mainly in, and secreted from, the phloem and its neighboring cells. The observation that TDIF is capable of promoting proliferation of procambial cells while suppressing xylem differentiation suggests that this small peptide functions as a phloem-derived, non-cell-autonomous signal that controls stem cell fate in the procambium. Our results indicate that we have discovered a cell communication system governing phloem-xylem cross-talk.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hirakawa
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Shinohara
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kondo
authors.forename: Asuka
authors.initials: A
authors.lastname: Inoue
authors.forename: Ikuko
authors.initials: I
authors.lastname: Nakanomyo
authors.forename: Mari
authors.initials: M
authors.lastname: Ogawa
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Sawa
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ohashi-Ito
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Matsubayashi
authors.forename: Hiroo
authors.initials: H
authors.lastname: Fukuda
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000187:drug effects / Q000235:genetics; D029681:Arabidopsis Proteins / Q000187:drug effects / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D002450:Cell Communication; D002454:Cell Differentiation; D049109:Cell Proliferation; D009842:Oligopeptides / Q000494:pharmacology / Q000502:physiology; D052585:Phloem / Q000166:cytology* / Q000187:drug effects; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects; D052584:Xylem / Q000166:cytology* / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D009842:Oligopeptides; C532424:tracheary element differentiation inhibitory factor, Arabidopsis