FAR-RED ELONGATED HYPOCOTYL1 and FHY1-LIKE Associate with the<i>Arabidopsis</i>Transcription Factors LAF1 and HFR1 to Transmit Phytochrome A Signals for Inhibition of Hypocotyl Elongation

Yang, Seong Wook; Jang, In‐Cheol; Henriques, Rossana; Chua, Nam Hai

doi:10.1105/tpc.109.067215

Cited by 78 publications

(89 citation statements)

References 42 publications

(119 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…FHY1 mediates not only phyA nuclear translocation through physical interaction (4, 6, 7) but also the assembly of the phyA/ FHY1/transcription factors complex with DNA (8,9,27). On the basis of our data, along with that of previous studies (8,9), it seems that both phyA and FHY1 coregulate the activity of their common target promoters in the phyA signaling complex, suggesting a coordinated action in transcriptional regulation.…”

Section: Discussionsupporting

confidence: 55%

Photoreceptor partner FHY1 has an independent role in gene modulation and plant development under far-red light

Chen

Demone

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

To incorporate the far-red light (FR) signal into a strategy for optimizing plant growth, FAR-RED ELONGATED HYPOCOTYL1 (FHY1) mediates the nuclear translocation of the FR photoreceptor phytochrome A (phyA) and facilitates the association of phyA with the promoters of numerous associated genes crucial for the response to environmental stimuli. However, whether FHY1 plays additional roles after FR irradiation remains elusive. Here, through the global identification of FHY1 chromatin association sites through ChIP-seq analysis and by the comparison of FHY1-associated sites with phyA-associated sites, we demonstrated that nuclear FHY1 can either act independently of phyA or act in association with phyA to activate the expression of distinct target genes. We also determined that phyA can act independently of FHY1 in regulating phyA-specific target genes. Furthermore, we determined that the independent FHY1 nuclear pathway is involved in crucial aspects of plant development, as in the case of inhibited seed germination under FR during salt stress. Notably, the differential presence of cis-elements and transcription factors in common and unique FHY1-and/or phyA-associated genes are indicative of the complexity of the independent and coordinated FHY1 and phyA pathways. Our study uncovers previously unidentified aspects of FHY1 function beyond its currently recognized role in phyA-dependent photomorphogenesis.L ight is one of the most important environmental cues in plant growth and development. Arabidopsis has thus evolved several photoreceptors to perceive different wavelengths in the visible light spectrum (1). Among them, phytochrome A (phyA) is the primary photoreceptor to mediate the far-red light (FR) and early red light (R) responses (2, 3). PhyA therefore plays a predominant role in plant adaptation to a shade environment where the R/FR ratio decreases. Upon FR and R irradiation phyA will shuttle between the inactive R-absorbing Pr form and the active FR-absorbing Pfr form. These two forms display distinct biological activities, nuclear translocation rates, degradation rates, and affinities for various signaling intermediates (2, 4, 5).Both FR and R trigger the localization of cytosolic phyA to the nucleus (6), albeit through different mechanisms. Two essential partners for phyA nuclear translocation, FAR-RED ELONGATED HYPOCOTYL1 (FHY1) and its less abundant homolog FHY1-LIKE (FHL), influence this process at two levels; first, after the initial burst of phyA nuclear importation under R, FHY1 is gradually phosphorylated by action of the Pfr form of phyA (7). This event inhibits the nuclear translocation of FHY1 and consequently prevents further nuclear accumulation of phyA. Under FR, however, persistent phyA nuclear translocation is observed with nonphosphorylated FHY1 (8); second, the nucleo-cytoplasmic shuttling of FHY1/FHL is also reduced under R owing to the low dissociation rate of the Pfr-FHY1/ FHL complex. The FR-driven phyA conversion to its Pr form benefits the recycling of FHY1/FHL for continuous phyA n...

show abstract

Section: Discussionsupporting

confidence: 55%

Photoreceptor partner FHY1 has an independent role in gene modulation and plant development under far-red light

Chen

Demone

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…For example, FAR-RED ELONGATED HYPOCOTYL1 (FHY1) and its homolog FHY1-LIKE (FHL) have been shown to form homodimers and heterodimers and then act together to regulate downstream events in Phytochrome A (PHYA) signaling, such as nuclear accumulation of PHYA and inhibition of hypocotyl elongation (Zhou et al, 2005;Hiltbrunner et al, 2006;Yang et al, 2009). Similarly, SPAs (for SUPPRESSOR OF PHYA) 1, 2, 3, and 4 are highly homologous proteins that can form homo-or heterodimers.…”

Section: Discussionmentioning

confidence: 99%

DWA1 and DWA2, Two Arabidopsis DWD Protein Components of CUL4-Based E3 Ligases, Act Together as Negative Regulators in ABA Signal Transduction

et al. 2010

View full text Add to dashboard Cite

To elucidate potential roles of CUL4-DDB1-DWD (for Cullin 4-Damaged DNA Binding1-DDB1 binding WD40) E3 ligases in abscisic acid (ABA) signaling, we examined ABA sensitivities of T-DNA mutants of a number of Arabidopsis thaliana DWD genes, which encode substrate receptors for CUL4 E3 ligases. Mutants in two DWD genes, DWA1 and DWA2 (DWD hypersensitive to ABA1 and 2), had ABA-hypersensitive phenotypes. Both proteins interacted with DDB1 in yeast two-hybrid assays and associated with DDB1 and CUL4 in vivo, implying they could form CUL4-based complexes. Several ABAresponsive genes were hyperinduced in both mutants, and the ABA-responsive transcription factors ABA INSENSITIVE 5 (ABI5) and MYC2 accumulated to high levels in the mutants after ABA treatment. Moreover, ABI5 interacted with DWA1 and DWA2 in vivo. Cell-free degradation assays showed ABI5 was degraded more slowly in dwa1 and dwa2 than in wild-type cell extracts. Therefore, DWA1 and/or DWA2 may be the substrate receptors for a CUL4 E3 ligase that targets ABI5 for degradation. Our data indicate that DWA1 and DWA2 can directly interact with each other, and their double mutants exhibited enhanced ABA and NaCl hypersensitivities, implying they can act together. This report thus describes a previously unknown heterodimeric cooperation between two independent substrate receptors for CUL4-based E3 ligases.

show abstract

“…FAR-RED ELONGATED HYPOCOTYL1 (FHY1) and its less abundant homolog FHY1-LIKE mediate FR responses by facilitating light-induced phyA nuclear translocation and by interacting with transcription factors (Yang et al, 2009;Rausenberger et al, 2011). Direct interaction of PIF3 with the FHY1-phyA complex has been proposed to underlie the regulation of anthocyanin biosynthesis .…”

Section: Pif Transcriptional Coregulatorsmentioning

confidence: 99%

PIFs: Systems Integrators in Plant Development

2014

View full text Add to dashboard Cite

FAR-RED ELONGATED HYPOCOTYL1 and FHY1-LIKE Associate with theArabidopsisTranscription Factors LAF1 and HFR1 to Transmit Phytochrome A Signals for Inhibition of Hypocotyl Elongation

Cited by 78 publications

References 42 publications

Photoreceptor partner FHY1 has an independent role in gene modulation and plant development under far-red light

Photoreceptor partner FHY1 has an independent role in gene modulation and plant development under far-red light

DWA1 and DWA2, Two Arabidopsis DWD Protein Components of CUL4-Based E3 Ligases, Act Together as Negative Regulators in ABA Signal Transduction

PIFs: Systems Integrators in Plant Development

Contact Info

Product

Resources

About