SPA1 — Arabidopsis thaliana

Summary

AT2G46340, known as SPA1 (SUPPRESSOR OF PHYA-105 1) in Arabidopsis thaliana, encodes a protein containing WD40 repeats and a protein kinase domain, and is annotated with phytochrome binding, photoreceptor activities, and transcriptional co-regulator function. SPA1 is associated with light responsiveness, detection of light, shade avoidance, and sucrose-mediated signaling, and localizes to nuclear ubiquitin ligase complexes and chromatin. The gene is linked to numerous traits including grain yield, leaf chlorophyll content, photoperiod sensitivity, far-red and blue light sensitivity, drought recovery, stem and panicle number, flower diameter, and phenolic compound content. It is also connected to UV-B stress responses, flavonoid accumulation, circadian clock entrainment, and stomatal closure. Studies of related genes in other species link the SPA1 family to anthocyanin pigmentation, shade tolerance, and grain yield.