CKX1 — Hordeum vulgare subsp. vulgare

Summary

HORVU.MOREX.R3.3HG0292960 (HvCKX1) on barley chromosome 3H encodes a cytokinin dehydrogenase (EC 1.5.99.12) with FAD-binding and cytokinin-binding domains, and also exhibits primary methylamine oxidase and phosphoglycerate transmembrane transporter activities. The gene is associated with cytokinin breakdown, signaling, and metabolism, as well as meristem, inflorescence, and seed development, stomatal complex morphogenesis, and immune and defense responses. HvCKX1 has been linked to root surface area and root hair number in barley, and to traits including tiller number, plant height, flowering time, photosynthetic rate, leaf morphology, chloroplast development, disease tolerance, and cytokinin content. It localizes to plastids, chloroplast envelope, ER lumen, vacuole, cytosol, and nucleus. Studies of related genes in other species connect the family to grain number, yield, root growth, salinity tolerance, and photosynthesis.