POX — Hordeum vulgare subsp. vulgare

Summary

HORVU.MOREX.R3.4HG0351890 (HvPOX) on barley chromosome 4H encodes a secretory haem peroxidase (EC 1.11.1.7) with lactoperoxidase, peroxidase, heme-binding and protein-binding activities. The enzyme is associated with activation of syringal lignin anabolism, xylem development, hydrogen peroxide catabolism, response to oxidative stress, water and hypoxia responses, and brassinosteroid-mediated signalling. It localises to the apoplast, plant-type cell wall, vacuole, Golgi, mitochondria, cytosol and extracellular space. The gene is linked to grain yield and weight, spike length, grains per spike, biological yield, stem and culm length, chlorophyll and protein content, flavonoid content, photosynthetic rate, nitrate uptake, root length, seedling growth, and ethylene sensitivity. Associations also include resistance to Botrytis cinerea, disease resistance, photoperiod stress response, cell proliferation and leaf development. Studies of related genes in other species link the family to lignin composition and biosynthesis, salt tolerance, and organ size.