title: The 14-amino acid CLV3, CLE19, and CLE40 peptides trigger consumption of the root meristem in Arabidopsis through a CLAVATA2-dependent pathway.
abstract: CLAVATA3 (CLV3), CLV3/ESR19 (CLE19), and CLE40 belong to a family of 26 genes in Arabidopsis thaliana that encode putative peptide ligands with unknown identity. It has been shown previously that ectopic expression of any of these three genes leads to a consumption of the root meristem. Here, we show that in vitro application of synthetic 14-amino acid peptides, CLV3p, CLE19p, and CLE40p, corresponding to the conserved CLE motif, mimics the overexpression phenotype. The same result was observed when CLE19 protein was applied externally. Interestingly, clv2 failed to respond to the peptide treatment, suggesting that CLV2 is involved in the CLE peptide signaling. Crossing of the CLE19 overexpression line with clv mutants confirms the involvement of CLV2. Analyses using tissue-specific marker lines revealed that the peptide treatments led to a premature differentiation of the ground tissue daughter cells and misspecification of cell identity in the pericycle and endodermis layers. We propose that these 14-amino acid peptides represent the major active domain of the corresponding CLE proteins, which interact with or saturate an unknown cell identity-maintaining CLV2 receptor complex in roots, leading to consumption of the root meristem.
authors.affiliation: Plant Research International, 6700 AA Wageningen, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Fiers
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Golemiec
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Lonneke
authors.initials: L
authors.lastname: van der Geest
authors.forename: Renze
authors.initials: R
authors.lastname: Heidstra
authors.forename: Willem
authors.initials: W
authors.lastname: Stiekema
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000033:anatomy & histology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018519:Meristem / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology
chemical_list: C118167:AT2G27250 protein, Arabidopsis; D029681:Arabidopsis Proteins; C506683:CLE40 protein, Arabidopsis; C401621:CLV2 protein, Arabidopsis; C483317:CLV3-ESR-related 19 protein, Arabidopsis; D008565:Membrane Proteins; D010455:Peptides