Methods and means for determining and conferring stress tolerance in plants

The current invention provides a method for rapid testing of stress tolerance in a plant and a method of producing plants with enhanced stress tolerance, in particular cold and/or drought tolerance. Such a method may be applied in breeding and selection programs for this trait, or for determining the timing of induction of stress and cold tolerance or hardening of a plant, for instance for agricultural purposes. The current invention exploits a difference in the temperature and light regimen induced transcriptional regulation of several types of dehydrins, in order to determine a ratio of dehydrin types that is indicative of cold and/or drought tolerance, induction of hardening and dormancy in a plant.