PAP5 — Hordeum vulgare subsp. vulgare

Summary

HORVU.MOREX.R3.2HG0103550 (HvPAP5, also known as HvSAG12) on barley chromosome 2H encodes a papain-like cysteine peptidase with thiol endopeptidase activity. The gene is associated with programmed cell death, floral organ senescence, and proteolysis, as well as responses to sugars, hormones (gibberellin, cytokinin, ethylene, auxin), UV-B, and fungal defence. It is linked to the mevalonate (MVA) and methylerythritol phosphate (MEP) pathways. The product localises to senescence-associated vacuoles, lysosomes, protein storage vacuoles, and the ER lumen. Associations with grain filling period and photosynthetic rate have been noted. The gene is associated with leaf senescence, seed yield, nitrogen remobilisation, drought resistance, and flooding tolerance. Related genes in other species are linked to developmental senescence and cadmium-induced programmed cell death.