title: A role for SENSITIVE TO FREEZING2 in protecting chloroplasts against freeze-induced damage in Arabidopsis.
abstract: The sensitive to freezing2 (SFR2) gene has an important role in freezing tolerance in Arabidopsis thaliana. We show that homologous genes are present, and expressed, in a wide range of terrestrial plants, including species not able to tolerate freezing. Expression constructs derived from the cDNAs of a number of different plant species, including examples not tolerant to freezing, are able to complement the freezing sensitivity of the Arabidopsis sfr2 mutant. In Arabidopsis the SFR2 protein is localized to the chloroplast outer envelope membrane, as revealed by the analysis of transgenic plants expressing SFR2 fusions to GFP, by confocal microscopy, and by the immunological analysis of isolated chloroplasts treated with thermolysin protease. Moreover, the chloroplasts of the sfr2 mutant show clear evidence of rapid damage after a freezing episode, suggesting a role for SFR2 in the protection of the chloroplast.
authors.affiliation: School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, UK.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fourrier
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Bédard
authors.forename: Enrique
authors.initials: E
authors.lastname: Lopez-Juez
authors.forename: Adrian
authors.initials: A
authors.lastname: Barbrook
authors.forename: John
authors.initials: J
authors.lastname: Bowyer
authors.forename: Paul
authors.initials: P
authors.lastname: Jarvis
authors.forename: Gareth
authors.initials: G
authors.lastname: Warren
authors.forename: Glenn
authors.initials: G
authors.lastname: Thorlby
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology; D002736:Chloroplasts / Q000235:genetics / Q000502:physiology*; D005615:Freezing; D017343:Genes, Plant; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000502:physiology; D007425:Intracellular Membranes; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D001617:beta-Glucosidase / Q000235:genetics* / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D018749:RNA, Plant; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; C492903:SFR2 protein, Arabidopsis; D001617:beta-Glucosidase