Interplay between cold-responsive gene regulation, metabolism and RNA processing during plant cold acclimation.

Temperate plants are capable of developing freezing tolerance when they are exposed to low nonfreezing temperatures. Acquired freezing tolerance involves extensive reprogramming of gene expression and metabolism. Recent full-genome transcript profiling studies, in combination with mutational and transgenic plant analyses, have provided a snapshot of the complex transcriptional network that operates under cold stress. Ubiquitination-mediated proteosomal protein degradation has a crucial role in regulating one of the upstream transcription factors, INDUCER OF CBF EXPRESSION 1 (ICE1), and thus in controlling the cold-responsive transcriptome. The changes in expression of hundreds of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Genetic analysis has revealed important roles for cellular metabolic signals, and for RNA splicing, export and secondary structure unwinding, in regulating cold-responsive gene expression and chilling and freezing tolerance.