The ability to increase freezing tolerance when exposed to low temperatures is a property of many plant species from temperate climates and involves a wide array of metabolic adjustments and changes in gene expression. In Arabidopsis thaliana, natural accessions show high variation in their acclimation capacity, and freezing tolerance correlates with natural habitat temperatures. To investigate the genetic basis of this variation, a recombinant inbred line population from reciprocal crosses between the accessions C24 and Tenela (Te), showing large variation in tolerance, was established. Over 250 recombinant inbred lines were genotyped for 69 single nucleotide polymorphism markers in a linkage map with 391.9 centimorgans (cM) and phenotyped for their freezing tolerance using the electrolyte leakage method that reports cell damage after a freeze-thaw cycle. Mapping of quantitative trait loci (QTL) for acclimated plants revealed three QTL regions on chromosomes 2, 4 and 5. Based on gene expression data, QTL regions were screened for genes differentially responding to low temperature in C24 and Te. Among the candidate genes, the Myb family transcription factor REVEILLE1 (At5g17300) on chromosome 5 was identified as a novel negative regulator of freezing tolerance in Arabidopsis.
Keywords: Arabidopsis; QTL mapping.; circadian; genetic variation; genome.
© 2012 John Wiley & Sons Ltd.