PR3 — Cucumis sativus

Summary

CsPR3 (CSA_6G509040) on cucumber chromosome 6 encodes a chitin-binding type-1 domain-containing protein with chitinase activity and chitin binding, placing it in the glycoside hydrolase family 19. This gene is associated with pathogen defense, defense responses to fungi, systemic acquired resistance, and jasmonic acid/ethylene-dependent signaling. It has been linked to appressorium formation, spore germination, cell wall macromolecule catabolism, chitin and polysaccharide breakdown, hydrogen peroxide biosynthesis, hypersensitive response-programmed cell death, and virus-induced post-transcriptional gene silencing. The encoded protein localizes to secretory vesicles, vacuoles, and the extracellular space. Associations with ethylene sensitivity, photosynthetic rate, salt tolerance, seed germination under salt stress, nematode resistance, and wilt symptom development have been noted. Studies of related chitinase family members in other species link the family to disease resistance traits including responses to Botrytis cinerea and bacterial wilt.