HY3 (A4A49_26492) — Nicotiana attenuata

Summary

A4A49_26492 (HY3/PHYB) on coyote tobacco chromosome 9 encodes a phytochrome B photoreceptor, a member of the phytochrome A-E family with domains including GAF, PAS, and histidine kinase. The gene is associated with tetrapyrrole binding and regulation of response to red or far red light, positive regulation of phytochrome signaling, and conversion between active and inactive PHYB forms. It is linked to photoperiod sensitivity, far red and blue light sensitivity, flowering under drought stress, and long day regulated expression of florigens. Associations include grain yield, panicle number, flower diameter, leaf area, plant dry weight, vegetative vigor, chlorophyll ratio, copper and glyphosate sensitivity, and root system morphology. The gene is also linked to drought escape via ABA-dependent pathways, defense response, disease resistance, and nitrogen, potassium, and phosphorus utilization.