HO1 — Cucumis sativus

Summary

CSA_1G328400 (HO1) on cucumber chromosome 1 encodes a heme oxygenase (decyclizing) enzyme (EC 1.14.14.18) with haem oxygenase-like domains, localized to the chloroplast thylakoid membrane and envelope. The gene is associated with heme breakdown, phytochromobilin anabolism, chloroplast-nucleus signaling, and cellular senescence. In cucumber, HO1 is linked to leaf chlorophyll content, plant height, stem diameter, root length, auxin and proline content, and adventitious root formation. It has been connected to salt stress response, stomatal closure, photomorphogenesis, flowering time, and chloroplast development. Studies of related genes in other species link the family to phytochrome chromophore synthesis, iron homeostasis, drought tolerance, and hypocotyl elongation. The gene is also associated with responses to nitrate, UV-C, and oxidative stress, as well as regulation of meristem size and photoperiodism.