A Novel Non-Canonical Rectifying Calcium Channel in Rice Triggers Cell Death Mediated Robust Immunity

Plants utilize calcium as a signaling molecule to regulate innate immunity, including PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI), in addition to controlling growth and development ^1,2 . Recent extensive research has highlighted that the activation of calcium ion (Ca ²⁺ ) channels during PTI and the formation of Ca ²⁺ channels during ETI are crucial for plant immunity ³ . However, comprehension on how crops substantially augment immunity through the enhancement of Ca ²⁺ channel activity remains limited. Here, we report a rice lesion mimic mutant, called etd1 (e licitors t riggered cell d eath 1 ), which also triggers cell death formation upon the challenge of rice blast elicitors. The recessive gain-of-function gene etd1 encodes a hypermorphic haplotype of OsCNGC13 which contains a single amino acid substitution of glycine-to-glutamate at the position of 483rd amino acid. The etd1 forms a novel non-canonical rectifying Ca ²⁺ channel that significantly enhances Ca ²⁺ influx. We position that etd1 -driven excessive Ca ²⁺ influx disrupts cellular calcium homeostasis, thereby triggering pathogen-induced cell death and conferring robust and broad-spectrum immunity to the rice blast pathogen.