calcium-dynamics
Calcium dynamics refers to the spatiotemporal patterns of calcium ion (Ca²⁺) signaling within plant cells, including the rapid fluctuations and waves that occur in response to environmental stimuli. Calcium serves as a critical second messenger in plants, translating diverse signals—such as touch, pathogen attack, drought, and temperature changes—into specific cellular responses. Understanding how plants encode and decode these calcium signatures is essential for unraveling the molecular basis of stress responses, growth regulation, and developmental processes.
PubMed · 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.
