Phytochrome B interacts with SWC6 and ARP6 to regulate H2A.Z deposition and photomorphogensis in <i>Arabidopsis</i>

Light serves as a crucial environmental cue which modulates plant growth and development, is controlled by multiple photoreceptors including the primary red light photoreceptor, phytochrome B (phyB). The signaling mechanism of phyB involves direct interactions with group basic helix-loop-helix (bHLH) transcription factors, PHYTOCHROME-INTERACTING FACTORS (PIFs), negative regulators photomorphogenesis, COP1 SPAs. H2A.Z an evolutionarily conserved H2A variant plays essential roles in transcriptional regulation. replacement catalyzed SWR1 complex. Here, we show that Pfr form physically interacts complex subunits SWC6 ARP6. ARP6 co-regulate numerous genes same direction, some are associated auxin biosynthesis response YUC9, encodes rate-limiting enzyme tryptophan-dependent pathway. Moreover, HY5/HYH act to inhibit hypocotyl elongation partially through repression biosynthesis. Based on our findings previous studies, propose promotes deposition at YUC9 its expression phyB-SWC6/ARP6 interactions, leading biosynthesis, thus inhibition light.