CKX1 — Oryza sativa Japonica

Summary

OsCKX1 (Os08g0460600) on rice chromosome 8 encodes a cytokinin dehydrogenase (EC 1.5.99.12) with FAD-binding domains, conferring cytokinin dehydrogenase activity. The gene is associated with cytokinin breakdown and signaling, meristem and inflorescence development, leaf senescence, and tissue homeostasis. It has been linked to grain number, grain size, grain weight, panicle number, spikelet number, tiller number, and overall yield. Associations also include root system architecture, crown root number, adventitious root initiation, shoot regeneration, callus formation, and responses to drought, salt, osmotic stress, and heat. The product localizes to plastids, chloroplast envelope, ER lumen, vacuole, cytosol, and nucleus. Studies of related genes in other species link the family to root growth, flowering, salinity tolerance, and disease resistance, while work in barley connects it to root surface area and root hair number.