CKX1 — Hordeum vulgare subsp. vulgare

Summary

HORVU.MOREX.R3.3HG0244590, designated HvCKX1 on barley chromosome 3H, encodes a cytokinin dehydrogenase (EC 1.5.99.12) with FAD binding and cytokinin dehydrogenase activity, and is also annotated for primary methylamine oxidase activity, phosphoglycerate transmembrane transporter activity, and antiporter activity. The gene is associated with cytokinin breakdown, signaling, and metabolism, as well as meristem, inflorescence, and seed development, immune and defense responses, and stomatal complex morphogenesis. Observed phenotypes in barley include effects on root surface area and root hair number. HvCKX1 has been linked to traits including cytokinin content, tiller number, plant height, flowering time, photosynthetic rate, root length, leaf morphology, chloroplast development, and disease tolerance. Studies of related genes in other species connect the CKX family to grain number, yield, root growth, salinity tolerance, and photosynthesis.