HY5 — Nicotiana attenuata

Summary

A4A49_33992 (HY5) in coyote tobacco (Nicotiana attenuata) encodes a bZIP transcription factor of the Hac1/HY5 family, with DNA-binding transcription activator activity, phytochrome binding, and red/far-red light photoreceptor activity. HY5 is associated with nicotine biosynthesis, upregulation of photosynthesis and lateral root development, regulation of phytochrome signaling, cellular water homeostasis, and sucrose-mediated signaling. It localizes to the nucleus, cytosol, plasmodesma, and mitochondria, and participates in ubiquitin-mediated degradation. Associations include osmotic adjustment, UV-A and blue light sensitivity, seed coat hardness, grain yield, leaf area, vegetative vigor, fruit quality, viral disease response, and starch grain synthesis. HY5 is also linked to bud outgrowth, fungal tolerance, lycopene content, mycorrhizal symbiosis, abscisic acid response, and gravitropic root growth. Related genes in other species are associated with carotenoid and phenylpropanoid biosynthesis, fruit ripening, and cold tolerance.