PCH1 regulates light, temperature, and circadian signaling as a structural component of phytochrome B-photobodies in Arabidopsis .

Autor:	Huang H; Donald Danforth Plant Science Center, St. Louis, MO 63132., McLoughlin KE; Department of Biology, Washington University in St. Louis, St. Louis, MO 63130., Sorkin ML; Donald Danforth Plant Science Center, St. Louis, MO 63132.; Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO 63130., Burgie ES; Department of Biology, Washington University in St. Louis, St. Louis, MO 63130., Bindbeutel RK; Donald Danforth Plant Science Center, St. Louis, MO 63132., Vierstra RD; Department of Biology, Washington University in St. Louis, St. Louis, MO 63130., Nusinow DA; Donald Danforth Plant Science Center, St. Louis, MO 63132; meter@danforthcenter.org.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2019 Apr 23; Vol. 116 (17), pp. 8603-8608. Date of Electronic Publication: 2019 Apr 04.
DOI:	10.1073/pnas.1818217116
Abstrakt:	The members of the phytochrome (phy) family of bilin-containing photoreceptors are major regulators of plant photomorphogenesis through their unique ability to photointerconvert between a biologically inactive red light-absorbing Pr state and an active far-red light-absorbing Pfr state. While the initial steps in Pfr signaling are unclear, an early event for the phyB isoform after photoconversion is its redistribution from the cytoplasm into subnuclear foci known as photobodies (PBs), which dissipate after Pfr reverts back to Pr by far-red irradiation or by temperature-dependent nonphotochemical reversion. Here we present evidence that PHOTOPERIODIC CONTROL OF HYPOCOTYL 1 (PCH1) functions both as an essential structural component of phyB-containing PBs and as a direct regulator of thermal reversion that is sufficient to stabilize phyB as Pfr in vitro. By examining the genetic interaction between a constitutively active phyB Y276H -YFP allele ( YHB-YFP ) and PCH1, we show that the loss of PCH1 prevents YHB from coalescing into PBs without affecting its nuclear localization, whereas overexpression of PCH1 dramatically increases PB levels. Loss of PCH1, presumably by impacting phyB-PB assembly, compromises a number of events elicited in YHB-YFP plants, including their constitutive photomorphogenic phenotype, red light-regulated thermomorphogenesis, and input of phyB into the circadian clock. Conversely, elevated levels of both phyB and PCH1 generate stable, yet far-red light-reversible PBs that persisted for days. Collectively, our data demonstrate that the assembly of PCH1-containing PBs is critical for phyB signaling to multiple outputs and suggest that altering PB dynamics could be exploited to modulate plant responses to light and temperature. Competing Interests: The authors declare no conflict of interest.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu