title: Growth temperature impact on leaf form and function in Arabidopsis thaliana ecotypes from northern and southern Europe.
abstract: The plasticity of leaf form and function in European lines of Arabidopsis thaliana was evaluated in ecotypes from Sweden and Italy grown under contrasting (cool versus hot) temperature regimes. Although both ecotypes exhibited acclimatory adjustments, the Swedish ecotype exhibited more pronounced responses to the two contrasting temperature regimes in several characterized features. These responses included thicker leaves with higher capacities for photosynthesis, likely facilitated by a greater number of phloem cells per minor vein for the active loading and export of sugars, when grown under cool temperature as opposed to leaves with a higher vein density and a greater number of tracheary elements per minor vein, likely facilitating higher rates of transpirational water loss (and thus evaporative cooling), when grown under hot temperature with high water availability. In addition, only the Swedish ecotype exhibited reduced rosette growth and greater levels of foliar tocopherols under the hot growth temperature. These responses, and the greater responsiveness of the Swedish ecotype compared with the Italian ecotype, are discussed in the context of redox signalling networks and transcription factors, and the greater range of environmental conditions experienced by the Swedish versus the Italian ecotype during the growing season in their native habitats.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA.
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Stewart
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Demmig-Adams
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Cohu
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA.
authors.forename: Coleman A
authors.initials: CA
authors.lastname: Wenzl
authors.affiliation: Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, Jülich, 52425, Germany.
authors.forename: Onno
authors.initials: O
authors.lastname: Muller
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309-0334, USA.
authors.forename: William W
authors.initials: WW
authors.lastname: Adams
mesh_terms: D017360:Arabidopsis / Q000033:anatomy & histology* / Q000254:growth & development / Q000378:metabolism; D007558:Italy; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000254:growth & development / Q000378:metabolism; D018526:Plant Transpiration; D058526:Plant Vascular Bundle / Q000254:growth & development; D013548:Sweden; D013696:Temperature; D024505:Tocopherols / Q000378:metabolism
chemical_list: D024505:Tocopherols
keywords: Foliar vasculature; phloem; photosynthesis; sieve elements; temperature acclimation; tracheary elements; xylem