PAP5 — Hordeum vulgare subsp. vulgare

Summary

HORVU.MOREX.R3.1HG0061980 (HvPAP5, also known as HvSAG12) on barley chromosome 1H encodes a papain-like cysteine peptidase of the C1A family, with thiol endopeptidase activity and proteinase-activated receptor binding. The gene is associated with programmed cell death during development, floral organ senescence, and proteolysis. It is linked to responses to multiple hormones including ethylene, cytokinin, auxin, and gibberellin, as well as to sugars (fructose, glucose, sucrose) and UV-B. The encoded protein localises to senescence-associated vacuoles, lysosomes, protein storage vacuoles, and the ER lumen. HvPAP5 is associated with leaf senescence, seed yield, nitrogen remobilization, grain filling period, photosynthetic rate, drought resistance, and flooding tolerance. Studies of related genes in other species link the family to developmental senescence, cadmium-induced programmed cell death, and saccharification efficiency.