HY3 — Daucus carota subsp. sativus

Summary

DCAR_001880 (HY3, also known as PHYA) on carrot chromosome 1 encodes a phytochrome A-E family member with tetrapyrrole binding activity and domains including GAF, PAS, and histidine kinase. The gene is associated with detection of light, regulation of response to red or far red light, positive regulation of phytochrome signaling pathway, and conversion between active and inactive PHYA forms. It is linked to numerous agronomic traits including grain yield, panicle number, flower diameter, root system morphology, subterranean shoot axis tuber size, leaf area, plant dry weight, vegetative vigor, photoperiod sensitivity, and light quality, far red light, and blue light sensitivity. Associations also include chlorophyll ratio, phenolic compound content, copper and glyphosate sensitivity, fruit set, inflorescence length, branch angle, and carpel morphology. Related genes in other species connect the phytochrome family to senescence, freezing stress tolerance, seed weight, carotenoid accumulation, and thermotolerance.