title: Multivariate genetic analysis of plant responses to water deficit and high temperature revealed contrasting adaptive strategies.
abstract: How genetic factors control plant performance under stressful environmental conditions is a central question in ecology and for crop breeding. A multivariate framework was developed to examine the genetic architecture of performance-related traits in response to interacting environmental stresses. Ecophysiological and life history traits were quantified in the Arabidopsis thaliana Ler × Cvi mapping population exposed to constant soil water deficit and high air temperature. The plasticity of the genetic variance-covariance matrix (G-matrix) was examined using mixed-effects models after regression into principal components. Quantitative trait locus (QTL) analysis was performed on the predictors of genotype effects and genotype by environment interactions (G × E). Three QTLs previously identified for flowering time had antagonistic G × E effects on carbon acquisition and the other traits (phenology, growth, leaf morphology, and transpiration). This resulted in a size-dependent response of water use efficiency (WUE) to high temperature but not soil water deficit, indicating that most of the plasticity of carbon acquisition and WUE to temperature is controlled by the loci that control variation of development, size, growth, and transpiration. A fourth QTL, MSAT2.22, controlled the response of carbon acquisition to specific combinations of watering and temperature irrespective of plant size and development, growth, and transpiration rate, which resulted in size-independent plasticity of WUE. These findings highlight how the strategies to optimize plant performance may differ in response to water deficit and high temperature (or their combination), and how different G × E effects could be targeted to improve plant tolerance to these stresses.
authors.affiliation: INRA, Montpellier SupAgro, UMR759 Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux (LEPSE), F-34060 Montpellier, France.
authors.forename: François
authors.initials: F
authors.lastname: Vasseur
authors.affiliation: INRA, Montpellier SupAgro, UMR759 Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux (LEPSE), F-34060 Montpellier, France.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Bontpart
authors.affiliation: INRA, Montpellier SupAgro, UMR759 Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux (LEPSE), F-34060 Montpellier, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Dauzat
authors.affiliation: INRA, Montpellier SupAgro, UMR759 Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux (LEPSE), F-34060 Montpellier, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Granier
authors.affiliation: INRA, Montpellier SupAgro, UMR759 Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux (LEPSE), F-34060 Montpellier, France denis.vile@supagro.inra.fr.
authors.forename: Denis
authors.initials: D
authors.lastname: Vile
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology*; D060146:Ecotype; D004777:Environment; D005163:Factor Analysis, Statistical; D059647:Gene-Environment Interaction; D005838:Genotype; D008954:Models, Biological; D015999:Multivariate Analysis; D010641:Phenotype; D063245:Plant Development / Q000235:genetics; D025341:Principal Component Analysis; D040641:Quantitative Trait Loci / Q000235:genetics; D013696:Temperature; D014867:Water
chemical_list: D014867:Water
keywords: Antagonistic pleiotropy; Arabidopsis thaliana; G-matrix; QTL; genotype by environment interactions; mixed-effects model; photosynthesis; water use efficiency.