Global changes in gene expression during sub-zero acclimation of three Arabidopsis thaliana accessions

During cold acclimation plants increase their freezing tolerance in response to low non-freezing temperatures. This is accompanied by many physiological, biochemical and molecular changes that have been extensively investigated. In addition, many cold acclimated plants become more freezing tolerant during exposure to mild, non-damaging sub-zero temperatures. There is hardly any information available about the molecular basis of this adaptation. However, Arabidopsis thaliana is among the species that acclimate to sub-zero temperatures. This makes it possible to use the molecular and genetic tools available in this species to identify components of sub-zero signal transduction and acclimation. Here, we have used microarrays and a qRT-PCR primer platform covering 1880 genes encoding transcription factors to monitor changes in gene expression in the accessions Columbia-0, Rschew and Tenela during the first three days of sub-zero acclimation at -3C. The results indicate that gene expression during sub-zero acclimation follows a tighly controlled time-course. Especially AP2/EREBP and WRKY transcription factors may be important regulators of sub-zero acclimation, although the CBF signal transduction pathway seems to be less important during sub-zero than during cold acclimation. Globally, we estimate that approximately 5% of all Arabidopsis genes are regulated during sub-zero acclimation. Particularly photosynthesis-related genes were down-regulated and genes belonging to the functional classes of cell wall biosynthesis, hormone metabolism and RNA regulation of transcription were up-regulated. Collectively, these data provide the first global analysis of gene expression during sub-zero acclimation and allow the identification of candidate genes for forward and reverse genetic studies into the molecular mechanisms of sub-zero acclimation.

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Le MQ, Pagter M, Hincha DK