10.1101_gad.205401.pdf (544.66 kB)
Download file

FHY1: a phytochrome A-specific signal transducer.

Download (544.66 kB)
journal contribution
posted on 08.12.2009, 16:11 by T. Desnos, P. Puente, Garry C. Whitelam, N.P. Harberd
Phytochromes are plant photoreceptors that regulate plant growth and development with respect to the light environment. Following the initial light-perception event, the phytochromes initiate a signal-transduction process that eventually results in alterations in cellular behavior, including gene expression. Here we describe the molecular cloning and functional characterization of Arabidopsis FHY1. FHY1 encodes a product (FHY1) that specifically transduces signals downstream of the far-red (FR) light-responsive phytochrome A (PHYA) photoreceptor. We show that FHY1 is a novel light-regulated protein that accumulates in dark (D)-grown but not in FR-grown hypocotyl cells. In addition, FHY1 transcript levels are regulated by light, and by the product of FHY3, another gene implicated in FR signaling. These observations indicate that FHY1 function is both FR-signal transducing and FR-signal regulated, suggesting a negative feedback regulation of FHY1 function. Seedlings homozygous for loss-of-function fhy1 alleles are partially blind to FR, whereas seedlings overexpressing FHY1exhibit increased responses to FR, but not to white (WL) or red (R) light. The increased FR-responses conferred by overexpression ofFHY1 are abolished in a PHYA-deficient mutant background, showing that FHY1 requires a signal from PHYA for function, and cannot modulate growth independently of PHYA.

History

Citation

Genes and Development, 2001, 15 (22), pp. 2980-2990

Version

VoR (Version of Record)

Published in

Genes and Development

Publisher

Cold Spring Harbor Laboratory Press

issn

0890-9369

eissn

1549-5477

Copyright date

2001

Available date

08/12/2009

Publisher version

http://genesdev.cshlp.org/content/15/22/2980

Language

en

Usage metrics

Categories

Keywords

Exports