title: Metabolome and water status phenotyping of Arabidopsis under abiotic stress cues reveals new insight into ESK1 function.
abstract: Metabolomic investigation of the freezing-tolerant Arabidopsis mutant esk1 revealed large alterations in polar metabolite content in roots and shoots. Stress metabolic markers were found to be among the most significant metabolic markers associated with the mutation, but also compounds related to growth regulation or nutrition. The metabolic phenotype of esk1 was also compared to that of wild type (WT) under various environmental constraints, namely cold, salinity and dehydration. The mutant was shown to express constitutively a subset of metabolic responses which fits with the core of stress metabolic responses in the WT. But remarkably, the most specific metabolic responses to cold acclimation were not phenocopied by esk1 mutation and remained fully inducible in the mutant at low temperature. Under salt stress, esk1 accumulated lower amounts of Na(+) in leaves than the WT, and under dehydration stress its metabolic profile and osmotic potential were only slightly impacted. These phenotypes are consistent with the hypothesis of an altered water status in esk1, which actually exhibited basic lower water content (WC) and transpiration rate (TR) than the WT. Taken together, the results suggest that ESK1 does not function as a specific cold acclimation gene, but could rather be involved in water homeostasis.
authors.affiliation: UMR 118 INRA, Agrocampus Ouest, Université de Rennes 1, Amélioration des Plantes et Biotechnologies Végétales, Campus de Beaulieu, bat 14A, 35042 Rennes Cedex, France.
authors.forename: Raphael
authors.initials: R
authors.lastname: Lugan
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Niogret
authors.forename: Lucie
authors.initials: L
authors.lastname: Kervazo
authors.forename: François Robert
authors.initials: FR
authors.lastname: Larher
authors.forename: Joachim
authors.initials: J
authors.lastname: Kopka
authors.forename: Alain
authors.initials: A
authors.lastname: Bouchereau
mesh_terms: D000123:Acetyltransferases; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D003681:Dehydration; D018506:Gene Expression Regulation, Plant; D008565:Membrane Proteins; D055442:Metabolome; D009154:Mutation; D009995:Osmosis; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018526:Plant Transpiration; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D008565:Membrane Proteins; D014867:Water; D012965:Sodium Chloride; D000123:Acetyltransferases; C523203:At3g55990 protein, Arabidopsis