TIR1 — Arabidopsis thaliana

Summary

AT3G62980, known as TIR1 (TRANSPORT INHIBITOR RESPONSE 1) in Arabidopsis thaliana, encodes an F-box and leucine-rich repeat-containing protein that exhibits auxin receptor activity, NEDD8 transferase activity, ubiquitin-like protein transferase activity, and auxin binding. TIR1 is associated with plant growth, lateral root development, root hair formation, adventitious root formation, leaf venation, and cell wall acidification. The protein localizes to the nuclear SCF complex and is linked to ubiquitination and degradation of AUX/IAA proteins, thermomorphogenesis, response to gravity, and glucosinolate breakdown. TIR1 has been connected to numerous traits including root width, sodium content, plant fresh weight, IAA content, seedling cotyledon size, molybdenum content, root shape, plastochron, leaf margin serration, pedicel length, inflorescence height, petal number, and floral organ number. Studies of related genes in other species link the TIR1 family to auxin sensitivity, lateral root formation, and inflorescence development.