PAP5 — Hordeum vulgare subsp. vulgare

Summary

HORVU.MOREX.R3.2HG0103560 (HvPAP5, also known as HvSAG12) on barley chromosome 2H encodes a papain-like cysteine peptidase belonging to the peptidase C1A family, with thiol endopeptidase activity and proteinase-activated receptor binding. The gene is associated with programmed cell death in cell development, floral organ senescence, and proteolysis, and is linked to responses to multiple hormones including ethylene, cytokinin, auxin, gibberellin, and sugars such as glucose, fructose, and sucrose. It has been connected to defence response to fungi, UV-B response, and both the MVA and MEP pathways. Localisation evidence places the product in senescence-associated vacuoles, lysosomes, protein storage vacuoles, and the ER lumen. Trait associations include grain filling period, photosynthetic rate, leaf senescence, seed yield, nitrogen remobilization, drought resistance, and flooding tolerance. Studies of related genes in other species link the family to developmental senescence, cadmium-induced programmed cell death, and bacterial resistance.