Molecular Mechanisms of Plant Responses to Cold Stress

This review is devoted to the molecular mechanisms of low positive temperature reception by plant cells. The role of primary sensors of cold exposure is discussed –Ca²⁺ channels and the COLD1 protein. Attention is paid to various directions of Ca²⁺-signaling: the Ca²⁺/calmodulin response involving CRLK1 and the Ca²⁺/calmodulin response involving transcription factors (TF) CAMTA are considered. All directions of Ca²⁺-signaling lead to the activation of the expression of CBFs genes, which are positively regulated by ICEs proteins and negatively by MYB15 protein. The presence of TF CBFs is necessary for the activation of a group of cold-regulated (COR) genes. COR genes encode proteins of different structure and function, which are united by the protective role they perform during low damaging temperatures. Among these genes are genes for proteins that stabilize membranes, regulate the activity of antioxidant enzymes, and activate the synthesis of cryoprotectors.