Winter plants acclimate to frost mainly during the autumn months, through the process of cold acclimation. Global climate change is causing changes in weather patterns such as the occurrence of warmer periods during late autumn or in winter. An increase in temperature after cold acclimation can decrease frost tolerance, which is particularly dangerous for winter crops. The aim of this study was to investigate the role of brassinosteroids (BRs) and BR analogues as protective agents against the negative results of deacclimation. Plants were cold-acclimated (3 weeks, 4 °C) and deacclimated (1 week, 16/9 °C d/n). Deacclimation generally reversed the cold-induced changes in the level of the putative brassinosteroid receptor protein (BRI1), the expression of BR-induced COR, and the expression of SERK1, which is involved in BR signal transduction. The deacclimation-induced decrease in frost tolerance in oilseed rape could to some extent be limited by applying steroid regulators. The deacclimation in plants could be detected using non-invasive measurements such as leaf reflectance, chlorophyll a fluorescence, and gas exchange monitoring.

• Keywords
• 24-epibrassinolide, 28-homocastasterone, BRI1, CO2 assimilation, COR, SERK, brassinosteroid analogues, chlorophyll a fluorescence, frost tolerance, leaf reflectance,
• MeSH
• Acclimatization * MeSH
• Brassica napus * physiology   metabolism   MeSH
• Brassinosteroids * metabolism   MeSH
• Plant Leaves metabolism   physiology   MeSH
• Cold Temperature * MeSH
• Gene Expression Regulation, Plant * MeSH
• Seasons MeSH
• Plant Proteins metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Brassinosteroids * MeSH
• Plant Proteins MeSH