Chaperonin-mediated Winter Cold Response via Circadian Clock Components in Arabidopsis

Vernalization and cold acclimation are plant strategies that evolved to enhance their fitness during the winter season. The molecular mechanisms behind these processes in Arabidopsis have been intensively studied. However, how plants measure the duration of long-term cold exposure has not been fully understood. Our research shows that cytosolic chaperonin is crucial for appropriate long-term cold responses by regulating plant circadian clocks. Furthermore, one of the clock components, REVEILLE4 (RVE4) and RVE8 directly activate VERNALIZATION INSENSITIVE 3 (VIN3) and the C-REPEAT BINDING FACTOR (CBF)/DEHYDRATION-RESPONSIVE ELEMENT BINDING 1 (DREB1) family genes, which are key regulators of vernalization and cold acclimation, respectively. The activation of the VIN3 and CBF/DREB1 genes was specific to the time of day, indicating that cold exposure during the day is critical for long-term cold responses. Our research delves deeper into understanding the regulatory mechanism governing these two distinct long-term cold responses.