PR3 — Cucumis sativus

Summary

CsPR3 (CSA_6G508520) on cucumber chromosome 6 encodes a chitinase with chitin-binding and catalytic domains (Glyco_hydro_19 family). It exhibits chitinase activity and chitin binding, and is associated with chitin breakdown, polysaccharide catabolism, and cell wall macromolecule catabolic processes. The gene is linked to defense responses, including systemic acquired resistance, jasmonic acid/ethylene-mediated signaling, hypersensitive response cell death, and defense against fungi. It has been connected to pathogen defense, disease resistance, and nematode resistance in cucumber, as well as to ethylene sensitivity, photosynthetic rate, salt tolerance, seed germination under salt stress, anthocyanin biosynthesis, and mycorrhization. The protein localizes to secretory vesicles, vacuoles, and extracellular spaces. Studies of related genes in other species link the family to virus resistance, bacterial wilt resistance, and Botrytis cinerea resistance.