Cytoplasmic calcium influx mediated by Lr14a regulates stomatal immunity against leaf rust in wheat

The wheat race-specific resistance gene Lr14a encodes an ankyrin-repeat transmembrane domain protein that confers immunity against the fungal pathogen Puccinia triticina, but the underlying mechanisms remain unclear. Here, using a range of biological systems and methods, we show that Lr14a functions as a Ca²⁺-permeable channel crucial for leaf rust resistance in wheat. Interestingly, we also found that the pathogen-inducible expression of Lr14a triggers guard cell hypersensitive response (HR) non-cell autonomously as a mechanism to control pathogen entry. Our results suggest that Lr14a regulates stomatal immunity non-cell autonomously through the mediation of calcium signaling.