POX — Sorghum bicolor

Summary

SbPOX (SORBI_3005G011300) on sorghum chromosome 5 encodes a haem peroxidase (EC 1.11.1.7) with lactoperoxidase, peroxidase, heme-binding, and protein-binding activities. This secretory peroxidase localises to the apoplast, cell wall, vacuole, Golgi, mitochondria, and cytosol. It is associated with xylem development, lignin anabolism (including syringal lignin activation), hydrogen peroxide catabolism, oxidative stress and defence responses, brassinosteroid signalling, hypoxia response, and homeostasis. The gene has been linked to grain yield, chlorophyll content, photosynthetic rate, transpiration rate, stomatal resistance, root length, seedling growth, leaf composition, carbohydrate and proline content, nitrate uptake, and ethylene sensitivity. It is also connected to disease resistance (including against Botrytis cinerea), photoperiod stress response, cell proliferation, leaf development, and signal transduction. Studies of related genes in other species link the family to lignin composition and biosynthesis, salt tolerance, organ size, calcium signalling, and protein-protein interactions.