title: Integration of low temperature and light signaling during cold acclimation response in Arabidopsis.
abstract: Certain plants increase their freezing tolerance in response to low nonfreezing temperatures, an adaptive process named cold acclimation. Light has been shown to be required for full cold acclimation, although how light and cold signals integrate and cross-talk to enhance freezing tolerance still remains poorly understood. Here, we show that HY5 levels are regulated by low temperature transcriptionally, via a CBF- and ABA-independent pathway, and posttranslationally, via protein stabilization through nuclear depletion of COP1. Furthermore, we demonstrate that HY5 positively regulates cold-induced gene expression through the Z-box and other cis-acting elements, ensuring the complete development of cold acclimation. These findings uncover unexpected functions for HY5, COP1, and the Z-box in Arabidopsis response to low temperature, provide insights on how cold and light signals integrate to optimize plant survival under freezing temperatures, and reveal the complexity of the molecular mechanisms plants have evolved to respond and adapt to their fluctuating natural environment.
authors.affiliation: Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas-Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Catalá
authors.forename: Joaquín
authors.initials: J
authors.lastname: Medina
authors.forename: Julio
authors.initials: J
authors.lastname: Salinas
mesh_terms: D000222:Adaptation, Physiological; D000872:Anthocyanins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D008027:Light; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D000872:Anthocyanins; D017382:Reactive Oxygen Species