title: Comparative transcriptomic analysis of salt adaptation in roots of contrasting Medicago truncatula genotypes.
abstract: Evolutionary diversity can be driven by the interaction of plants with different environments. Molecular bases involved in ecological adaptations to abiotic constraints can be explored using genomic tools. Legumes are major crops worldwide and soil salinity is a main stress affecting yield in these plants. We analyzed in the Medicago truncatula legume the root transcriptome of two genotypes having contrasting responses to salt stress: TN1.11, sampled in a salty Tunisian soil, and the reference Jemalong A17 genotype. TN1.11 plants show increased root growth under salt stress as well as a differential accumulation of sodium ions when compared to A17. Transcriptomic analysis revealed specific gene clusters preferentially regulated by salt in root apices of TN1.11, notably those related to the auxin pathway and to changes in histone variant isoforms. Many genes encoding transcription factors (TFs) were also differentially regulated between the two genotypes in response to salt. Among those selected for functional studies, overexpression in roots of the A17 genotype of the bHLH-type TF most differentially regulated between genotypes improved significantly root growth under salt stress. Despite the global complexity of the differential transcriptional responses, we propose that an increase in this bHLH TF expression may be linked to the adaptation of M. truncatula to saline soil environments.
authors.affiliation: Institut des Sciences du Végétal, CNRS, 91198 Gif-sur-Yvette, France.
authors.forename: Ons
authors.initials: O
authors.lastname: Zahaf
authors.forename: Sandrine
authors.initials: S
authors.lastname: Blanchet
authors.forename: Axel
authors.initials: A
authors.lastname: de Zélicourt
authors.forename: Benoît
authors.initials: B
authors.lastname: Alunni
authors.forename: Julie
authors.initials: J
authors.lastname: Plet
authors.forename: Carole
authors.initials: C
authors.lastname: Laffont
authors.forename: Laura
authors.initials: L
authors.lastname: de Lorenzo
authors.forename: Sandrine
authors.initials: S
authors.lastname: Imbeaud
authors.forename: Jean-Laurent
authors.initials: JL
authors.lastname: Ichanté
authors.forename: Anouck
authors.initials: A
authors.lastname: Diet
authors.forename: Mounawer
authors.initials: M
authors.lastname: Badri
authors.forename: Ana
authors.initials: A
authors.lastname: Zabalza
authors.forename: Esther M
authors.initials: EM
authors.lastname: González
authors.forename: Hervé
authors.initials: H
authors.lastname: Delacroix
authors.forename: Véronique
authors.initials: V
authors.lastname: Gruber
authors.forename: Florian
authors.initials: F
authors.lastname: Frugier
authors.forename: Martin
authors.initials: M
authors.lastname: Crespi
mesh_terms: D000222:Adaptation, Physiological; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D046913:Medicago truncatula / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride