Cold Acclimation and Freezing Tolerance in Plants

Abstract

Abstract The capacity to survive winter conditions varies greatly in the plant kingdom. Cold acclimation is the process leading to the development of freezing tolerance in plants. It is a complex multigenic process that requires a programmed and integrated genetic capacity to activate the appropriate mechanisms needed to withstand harsh winter conditions. Hardy plants have evolved complex mechanisms to tightly regulate gene expression, including events at the transcriptional and post‐transcriptional levels. Hundreds of cold‐induced genes encoding structural and regulatory proteins have been identified. These proteins have been found in many species, but in most cases, they had been first identified in model species. Most of the studies in the field are still performed with the model dicotyledonous plant Arabidopsis , but Brachypodium distachyon is emerging as a model for monocotyledonous species. Key Concepts: Plants must possess the genetic makeup to develop tolerance to harsh winter conditions. Low temperature induces the expression of many genes in plants. The C‐repeat binding factor (CBF) pathway is still the only identified pathway that regulates gene expression at low temperature. The existence of the CBF components in a species does not ensure the capacity to cold acclimate. Although microRNAs associated with cold response have been discovered, few have been assigned to specific physiological events in the cold acclimation process. Few links between the regulation of cold stress response and chromatin dynamics have been identified in plants thus far. Brachypodium distachyon is a potential model for the study of cold acclimation.