Molecular responses to thermal stress in woody plants

Abstract

Stress caused by high and low temperatures has been much less studied in woody plants than in herbaceous ones. The cold response shows specific traits in woody plants. Cold acclimation associated to winter dormancy develops in two sequential steps: the first is triggered by photoperiod shortening while the second requires temperatures to fall. The involvement of ABA in cold acclimation is beyond question, yet the roles played by this hormone are far better understood in herbaceous plants. The induction of protective proteins and changes in both glycan metabolism and circadian clock functioning are noteworthy among the molecular responses of woody species to low temperatures. Both herbaceous and woody plants seem to respond similarly to heat stress, with heat shock proteins (HSPs) dominating protein synthesis profiles. Certain HSPs are also induced in response to low temperatures, and recent data suggest that they are involved in cold acclimation.