cold-stress
Cold stress refers to the physiological and molecular responses plants experience when exposed to low temperatures, ranging from chilling injury to freezing damage. Unlike animals, plants cannot escape harsh temperature conditions and must rely on biochemical adaptations—such as membrane remodeling, cryoprotectant accumulation, and altered gene expression—to survive. Understanding cold stress mechanisms is critical for developing crops that can withstand late frosts, early winters, and climate variability, helping to protect agricultural yields worldwide.
open_in_new WikipediaPubMed · 2026-02-19
Scientists discovered a three-protein molecular switch in apple trees that controls how cells flood with calcium during cold stress — a key early alarm signal that helps the plant survive freezing. The system is self-regulating: it turns on when temperatures drop and automatically dials back once calcium levels get too high.
MdCNGC1C, a calcium channel, is activated by the kinase MdOST1 via phosphorylation at a specific site (Serine-47), directly enhancing calcium influx and freezing tolerance in apple.
The calcium sensor protein MdCaM7.1 competes with MdOST1 for binding to the same region (N-terminus) of MdCNGC1C, and when it wins, it inhibits calcium entry and reduces cold tolerance.
Elevated cytoplasmic calcium concentrations promote MdCaM7.1 binding and suppress MdOST1 activity, revealing a calcium-dependent negative feedback loop that self-limits cold-induced calcium signaling.
