Hormones, NO, Antioxidants and Metabolites as Key Players in Plant Cold Acclimation

Abstract

The freezing tolerance of winter hardy plants is a dynamic feature; which changes in response to changing environmental conditions, especially low temperature. The cold stress acclimation process is dynamically regulated by plant hormones, which exert their function in intensive cross-talk. Plant hormones function either in an interaction with redox signalling or independently. They influence the acclimation in a time-dependent manner. These processes include both reactive oxygen and nitrogen species (ROS and RNS), which are involved in redox regulation and integrate signals from the environment as well as metabolism, thus contributing to the control of development and defence. During cold acclimation, one of the most characteristic phenomenon is the reprogramming of gene expression resulting in accumulation of not only protective proteins but also hundreds of other metabolites, some of which are known to have protective effects. This chapter is focused on the elucidation of the role of plant hormones in the individual phases of the cold stress response and also on their interactions with ROS and RNS and other metabolites.