A nuclear-localized protein, KOLD SENSITIV-1, affects the expression of cold-responsive genes during prolonged chilling in Arabidopsis.
Plants respond to cold by transcriptional and metabolic responses which underlie tolerance and acclimation mechanisms, but details at the molecular level are incomplete. Here we describe KOLD SENSITIV-1 (KOS1), a new gene required for responses to cold. KOS1 protein is predicted to have coiled-coil, Structural Maintenance of Chromosomes and nuclear-targeting domains. GFP-labeled KOS1 localizes to the nucleus. Null mutants could not be isolated but two independent knockdown T-DNA mutants were obtained. Growth and development of kos1 knockdown mutant plants was comparable to wild type when grown at 21°C. However, when grown at 4°C these mutants exhibited accelerated leaf yellowing and smaller rosette size than wild type. Quantitative RT-PCR revealed that in the cold kos1 mutants had reduced expression of cold-responsive transcripts COR15A, COR15B, BAM3 and AMY3. Metabolite profiling revealed that ascorbate levels were lower in the mutants in the cold relative to wild type. KOS1 therefore represents a new gene that influences the regulation of transcript and metabolite levels in response to prolonged chilling temperatures.
Purdy
Sarah J
SJ
Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Stirling Highway, Crawley, Perth, Western Australia, 6009, Australia.
Bussell
John D
JD
Nelson
David C
DC
Villadsen
Dorthe
D
Smith
Steven M
SM
D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D003080:Cold Temperature; D008401:Gas Chromatography-Mass Spectrometry; D018506:Gene Expression Regulation, Plant; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D013213:Starch / Q000378:metabolism
D009687:Nuclear Proteins; D010940:Plant Proteins; D013213:Starch; D001205:Ascorbic Acid