title: Time-dependent deacclimation after cold acclimation in Arabidopsis thaliana accessions.
abstract: During low temperature exposure, Arabidopsis thaliana and many other plants from temperate climates increase in freezing tolerance in a process termed cold acclimation. However, the correct timing and rate of deacclimation, resulting in loss of freezing tolerance and initiation of growth is equally important for plant fitness and survival. While the molecular basis of cold acclimation has been investigated in detail, much less information is available about deacclimation. We have characterized the responses of 10 natural accessions of Arabidopsis thaliana that vary widely in their freezing tolerance, to deacclimation conditions. Sugar, proline and transcript levels declined sharply over three days in all accessions after transfer of cold acclimated plants to ambient temperatures, while freezing tolerance only declined in tolerant accessions. Correlations between freezing tolerance and the expression levels of COR genes and the content of glucose, fructose and sucrose, as well as many correlations among transcript and solute levels, that were highly significant in cold acclimated plants, were lost during deacclimation. Other correlations persisted, indicating that after three days of deacclimation, plant metabolism had not completely reverted back to the non-acclimated state. These data provide the basis for further molecular and genetic studies to unravel the regulation of deacclimation.
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany.
authors.forename: Ellen
authors.initials: E
authors.lastname: Zuther
authors.affiliation: FU Berlin, Institute of Biology, DCPS, Plant Physiology, Königin-Luise-Straße 12-16, 14195 Berlin, Germany.
authors.forename: Ilona
authors.initials: I
authors.lastname: Juszczak
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany.
authors.forename: Yang Ping
authors.initials: YP
authors.lastname: Lee
authors.affiliation: FU Berlin, Institute of Biology, DCPS, Plant Physiology, Königin-Luise-Straße 12-16, 14195 Berlin, Germany.
authors.forename: Margarete
authors.initials: M
authors.lastname: Baier
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany.
authors.forename: Dirk K
authors.initials: DK
authors.lastname: Hincha
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D005615:Freezing; D005632:Fructose / Q000032:analysis; D005947:Glucose / Q000032:analysis; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D011887:Raffinose / Q000032:analysis
chemical_list: D029681:Arabidopsis Proteins; D005632:Fructose; D005947:Glucose; D011887:Raffinose