CBF-mediated plant cold response: from linear cascade to multilayered network

The ICE1 - CBF - COR cascade has framed plant cold-stress biology for two decades, but revised ICE1 models, CBF-SKIP liquid-liquid phase separation, and antisense-RNA activation of CBF via R-loops reveal network-level complexity beyond the linear paradigm. We organize current knowledge as eight functionally coupled layers—cold perception and calcium signaling; transcriptional control; epigenetic and non-coding RNA regulation; post-translational modification and protein stability; hormone signaling; ROS and metabolic regulation; CBF -independent parallel pathways; and feedback/feed-forward control. We present this multilayered organization explicitly as an evidence-organized conceptual framework, not as a fully resolved molecular network, because some inter-layer connections rest on correlational or indirect evidence. We distinguish direct molecular and genetic evidence from transcriptomic or physiological inference and do not treat genetic and direct molecular evidence as equivalent. Cross-species comparisons reveal marked climate-associated divergence and caution against transferring Arabidopsis models uncritically to crops. We survey gene-family evolution, multilayered regulation, climate-zone divergence and breeding applications, and scrutinize unresolved issues—condensate physiology, ICE1 redundancy, CBF -independent pathways-alongside blind spots such as model-organism bias and the lab-to-field gap. Mapping where the field stands and diagnosing these gaps should help future work generate substantive, rather than incremental, insight into how plants sense and respond to low temperature.