title: Abscisic acid promotes pre-emergence stages of lateral root development in Medicago truncatula.
abstract: The plant root system is important for plant anchorage and nutrition. Among the different characteristics of the root system, root branching is a major factor of plasticity and adaptation to changing environments. Indeed, many biotic and abiotic stresses, such as drought or symbiotic interactions, influence root branching. Many studies concerning root development and root branching were performed on the model plant Arabidopsis thaliana, but this model plant has a very simplified root structure and is not able to establish any symbiotic interactions. We have recently described 7 stages for lateral root development in the model legume Medicago truncatula and found significant differences in the tissular contribution of root cell layers to the formation of new lateral roots (LR). We have also described 2 transgenic lines expressing the DR5:GUS and DR5:VENUS-N7 reporter genes that are useful to follow LR formation at early developmental stages. Here, we describe the use of these transgenic lines to monitor LR developmental responses of M. truncatula to the phytohormone abscisic acid (ABA) which is a major actor of stress and symbiotic interactions. We show that ABA promotes the formation of new lateral root primordia and their development, mostly at the late, pre-emergence stage.
authors.affiliation: a INRA UMR 441, Laboratoire des Interactions Plantes-Microorganismes (LIPM) ; Castanet-Tolosan , France.
authors.forename: Anne-Alicia
authors.initials: AA
authors.lastname: Gonzalez
authors.forename: Kokoévi
authors.initials: K
authors.lastname: Agbévénou
authors.forename: Violaine
authors.initials: V
authors.lastname: Herrbach
authors.forename: Clare
authors.initials: C
authors.lastname: Gough
authors.forename: Sandra
authors.initials: S
authors.lastname: Bensmihen
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D046913:Medicago truncatula / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D063245:Plant Development / Q000187:drug effects / Q000502:physiology; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development*; D030821:Plants, Genetically Modified
chemical_list: D000040:Abscisic Acid
keywords: DR5: GUS and DR5:VENUS transgenic lines; Medicago truncatula; abscisic acid (ABA); lateral root development