Comparative functional analysis of full‐length and N‐terminal fragments of phytochrome C, D and E in red light‐induced signaling. Issue 1 (17th June 2013)

• Record Type: Journal Article
• Authors: Ádám, Éva; Kircher, Stefan; Liu, Peng; Mérai, Zsuzsanna; González‐Schain, Nahuel; Hörner, Maximilian; Viczián, András; Monte, Elena; Sharrock, Robert A.; Schäfer, Eberhard; Nagy, Ferenc
• Is Part Of: New phytologist. Volume 200:Issue 1(2013)
• Page Start: 86
• Page End: 96
• Publication Date: 2013-06-17
• Subjects: nuclear body formation -- nuclear translocation -- photomorphogenesis -- photoreceptor -- phytochrome E; Botany -- Periodicals; 580
• DOI: 10.1111/nph.12364
• Languages: English
• ISSNs: 0028-646X

Abstract

Summary: Phytochromes (phy) C, D and E are involved in the regulation of red/far‐red light‐induced photomorphogenesis of Arabidopsis thaliana, but only limited data are available on the mode of action and biological function of these lesser studied phytochrome species. We fused N‐terminal fragments or full‐length PHYC, D and E to YELLOW FLUORESCENT PROTEIN (YFP), and analyzed the function, stability and intracellular distribution of these fusion proteins in planta . The activity of the constitutively nuclear‐localized homodimers of N‐terminal fragments was comparable with that of full‐length PHYC, D, E‐YFP, and resulted in the regulation of various red light‐induced photomorphogenic responses in the studied genetic backgrounds. PHYE‐YFP was active in the absence of phyB and phyD, and PHYE‐YFP controlled responses, as well as accumulation, of the fusion protein in the nuclei, was saturated at low fluence rates of red light and did not require functional FAR‐RED ELONGATED HYPOCOTYL1 (FHY‐1) and FHY‐1‐like proteins. Our data suggest that PHYC‐YFP, PHYD‐YFP and PHYE‐YFP fusion proteins, as well as their truncated N‐terminal derivatives, are biologically active in the modulation of red light‐regulated photomorphogenesis. We propose that PHYE‐YFP can function as a homodimer and that low‐fluence red light‐induced translocation of phyE and phyA into the nuclei is mediated by different molecular mechanisms.