PubMed · 2026-04-21
Scientists discovered how plants sound a molecular alarm when attacked by pathogens or damaged: a chain of protein signals blocks an acid pump on cell surfaces, making the fluid around cells more alkaline. This pH shift acts as a key messenger that helps plants mount their immune response.
A phosphorelay signaling circuit (a chain of proteins passing chemical tags) drives extracellular alkalinization downstream of cell-surface immune receptors
The mechanism works by inhibiting autoinhibited H+-ATPase proton pumps, reducing acid secretion and raising extracellular pH
Extracellular alkalinization functions as an active signaling component in both pathogen-triggered immunity (PTI) and cell-wall damage responses, not merely a passive byproduct