HY3 — Nicotiana attenuata

Summary

A4A49_27485 (HY3/PHYB) in coyote tobacco (Nicotiana attenuata) encodes a phytochrome B photoreceptor, a member of the phytochrome A-E family with domains including PAS, GAF, and histidine kinase. The gene is associated with tetrapyrrole binding and regulation of responses to red or far-red light, as well as positive regulation of the phytochrome signaling pathway. It is linked to diverse processes including protein-phycocyanobilin linkage, downregulation of chlorophyll anabolism, and regulation of plant organ formation. Associations with agronomically relevant traits include grain yield, panicle number, flower diameter, leaf area, photoperiod sensitivity, far-red light sensitivity, chlorophyll ratio, plant dry weight, and vegetative vigor. The gene is also connected to phenotypes such as delayed flowering, drought stress response, cold stress response, disease resistance, and carbon assimilation. Studies of related genes in other species link the family to flowering time, tuberization, fruit ripening, and biotic stress resistance.