title: Nodule numbers are governed by interaction between CLE peptides and cytokinin signaling.
abstract: CLE peptides are involved in the balance between cell division and differentiation throughout plant development, including nodulation. Previously, two CLE genes of Medicago truncatula, MtCLE12 and MtCLE13, had been identified whose expression correlated with nodule primordium formation and meristem establishment. Gain-of-function analysis indicated that both MtCLE12 and MtCLE13 interact with the SUPER NUMERIC NODULES (SUNN)-dependent auto-regulation of nodulation to control nodule numbers. Here we demonstrate that cytokinin, which is essential for nodule organ formation, regulates MtCLE13 expression. In addition, simultaneous knockdown of MtCLE12 and MtCLE13 resulted in an increase in nodule number, implying that both genes play a role in controlling nodule number. Additionally, a weak link may exist with the ethylene-dependent mechanism that locally controls nodule number.
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.
authors.forename: Virginie
authors.initials: V
authors.lastname: Mortier
authors.forename: Eva
authors.initials: E
authors.lastname: De Wever
authors.forename: Marnik
authors.initials: M
authors.lastname: Vuylsteke
authors.forename: Marcelle
authors.initials: M
authors.lastname: Holsters
authors.forename: Sofie
authors.initials: S
authors.lastname: Goormachtig
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003583:Cytokinins / Q000494:pharmacology*; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D055785:Gene Knockdown Techniques; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D008954:Models, Biological; D009154:Mutation; D010455:Peptides / Q000235:genetics* / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D055170:Plant Root Nodulation / Q000187:drug effects / Q000235:genetics*; D030821:Plants, Genetically Modified; D053204:Root Nodules, Plant / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D016962:Sinorhizobium meliloti / Q000187:drug effects / Q000502:physiology; D013559:Symbiosis
chemical_list: D003583:Cytokinins; D005030:Ethylenes; D010455:Peptides; D010937:Plant Growth Regulators; D010940:Plant Proteins; C036216:ethylene