Advances and opportunities in unraveling cold-tolerance mechanisms in the world's primary staple food crops

Temperatures below or above optimal growth conditions are among the major stressors affecting productivity, end-use quality, and distribution of key staple crops including rice (Oryza sativa), wheat (Triticum aestivum), and maize (Zea mays L.). Among temperature stresses, cold stress induces cellular changes that cause oxidative stress and slowdown metabolism, limit growth, and ultimately reduce crop productivity. Perception of cold stress by plant cells leads to the activation of cold-responsive transcription factors and downstream genes, which ultimately impart cold tolerance. The response triggered in crops to cold stress includes gene expression/suppression, the accumulation of sugars upon chilling, and signaling molecules, among others. Much of the information on the effects of cold stress on perception, signal transduction, gene expression, and plant metabolism are available in the model plant Arabidopsis but somewhat lacking in major crops. Hence, a complete understanding of the molecular mechanisms by which staple crops respond to cold stress remain largely unknown. Here, we make an effort to elaborate on the molecular mechanisms employed in response to low-temperature stress. We summarize the effects of cold stress on the growth and development of these crops, the mechanism of cold perception, and the role of various sensors and transducers in cold signaling. We discuss the progress in cold tolerance research at the genome, transcriptome, proteome, and metabolome levels and highlight how these findings provide opportunities for designing cold-tolerant crops for the future. Cold stress significantly affects plant growth and development, particularly in staple food crops (rice, wheat, and maize) that are often grown in regions with cold climates.Understanding the physiological, biochemical, and molecular mechanisms that plants use to respond and adapt to cold stress is crucial for developing cold-tolerant varieties of staple food crops.Advances in various technologies, such as transcriptomics, proteomics, and gene editing, have provided insights into the genetic and molecular mechanisms underlying cold tolerance in staple food crops.The knowledge gained from these technological advancements can be applied to develop new breeding strategies and crop improvement techniques to produce cold-tolerant varieties of staple food crops ensuring food security in regions that experience cold stress.