HY5 — Cucumis melo

Summary

MELO3C011250.2, designated CmHY5 on melon chromosome 4, encodes a bZIP transcription factor of the Hac1/HY5 family with DNA-binding transcription activator activity, RNA polymerase II-specific, and also annotated with phytochrome binding, red/far-red light photoreceptor activity, and histidine kinase activity. CmHY5 is associated with regulation of the phytochrome signaling pathway, upregulation of photosynthesis and lateral root development, cellular water homeostasis, sucrose-mediated signaling, nitrate import, and protein monoubiquitination. The gene is linked to numerous agronomic traits including fruit quality, grain yield, total soluble sugar content, seed coat hardness, leaf area, vegetative vigor, osmotic adjustment capacity, and responses to light quality, UV-A, far-red, and blue light. It localizes to the nuclear ubiquitin ligase complex, plasmodesma, and mitochondria. Studies of related genes in other species connect the family to light signaling, photoperiod-dependent flowering, and peroxisomal matrix protein import.