SPA1: A New Genetic Locus Involved in Phytochrome A- Specific Signal Transduction

Correspondence to: Peter H. Quail, quail{at}nature.berkeley.edu (E-mail), 510-559-5678 (fax).

To identify mutants potentially defective in signaling intermediates specific to phytochrome A (phyA), we screened for extragenic mutations that suppress the morphological phenotype exhibited by a weak phyA mutant (phyA-105) of Arabidopsis. A new recessive mutant, designated spa1 (for suppressor of phyA-105), was isolated and mapped to the bottom of chromosome 2. spa1 phyA-105 double mutants exhibit restoration of several responses to limiting fluence rates of continuous far-red light that are absent in the parental phyA-105 mutant, such as deetiolation, anthocyanin accumulation, and a far-red light-induced inability of seedlings to green upon subsequent transfer to continuous white light. spa1 mutations do not cause a phenotype in darkness, indicating that the suppression phenotype is light dependent. Enhanced photoresponsiveness was observed in spa1 seedlings in a wild-type PHYA background as well as in the mutant phyA-105 background but not in a mutant phyA null background. These results indicate that phyA is necessary in a non-allele-specific fashion for the expression of the spa1 mutant phenotype and that phyB to phyE are not sufficient for this effect. Taken together, the data suggest that spa1 mutations specifically amplify phyA signaling and therefore that the SPA1 locus encodes a component that acts negatively early in the phyA-specific signaling pathway.

Related articles in Plant Cell:

SPA-rring Partner for Phytochrome A?

Crispin B. Taylor
Plant Cell 1998 10: 1-3. [Full Text]  

This article has been cited by other articles:

				L.-J. Liu, Y.-C. Zhang, Q.-H. Li, Y. Sang, J. Mao, H.-L. Lian, L. Wang, and H.-Q. Yang COP1-Mediated Ubiquitination of CONSTANS Is Implicated in Cryptochrome Regulation of Flowering in Arabidopsis PLANT CELL, February 1, 2008; 20(2): 292 - 306. [Abstract] [Full Text] [PDF]

				I.-C. Jang, S. W. Yang, J.-Y. Yang, and N.-H. Chua Independent and interdependent functions of LAF1 and HFR1 in phytochrome A signaling Genes & Dev., August 15, 2007; 21(16): 2100 - 2111. [Abstract] [Full Text] [PDF]

				R. Khanna, Y. Shen, G. Toledo-Ortiz, E. A. Kikis, H. Johannesson, Y.-S. Hwang, and P. H. Quail Functional Profiling Reveals That Only a Small Number of Phytochrome-Regulated Early-Response Genes in Arabidopsis Are Necessary for Optimal Deetiolation PLANT CELL, September 1, 2006; 18(9): 2157 - 2171. [Abstract] [Full Text] [PDF]

				S. Laubinger, V. Marchal, J. Gentilhomme, S. Wenkel, J. Adrian, S. Jang, C. Kulajta, H. Braun, G. Coupland, and U. Hoecker Arabidopsis SPA proteins regulate photoperiodic flowering and interact with the floral inducer CONSTANS to regulate its stability Development, August 15, 2006; 133(16): 3213 - 3222. [Abstract] [Full Text] [PDF]

				M. Chen and M. Ni RED AND FAR-RED INSENSITIVE 2, a RING-Domain Zinc Finger Protein, Mediates Phytochrome-Controlled Seedling Deetiolation Responses Plant Physiology, February 1, 2006; 140(2): 457 - 465. [Abstract] [Full Text] [PDF]

				Y. Shen, S. Feng, L. Ma, R. Lin, L.-J. Qu, Z. Chen, H. Wang, and X. W. Deng Arabidopsis FHY1 Protein Stability Is Regulated by Light via Phytochrome A and 26S Proteasome Plant Physiology, November 1, 2005; 139(3): 1234 - 1243. [Abstract] [Full Text] [PDF]

				V. Yadav, C. Mallappa, S. N. Gangappa, S. Bhatia, and S. Chattopadhyay A Basic Helix-Loop-Helix Transcription Factor in Arabidopsis, MYC2, Acts as a Repressor of Blue Light-Mediated Photomorphogenic Growth PLANT CELL, July 1, 2005; 17(7): 1953 - 1966. [Abstract] [Full Text] [PDF]

				J. Yang, R. Lin, J. Sullivan, U. Hoecker, B. Liu, L. Xu, X. W. Deng, and H. Wang Light Regulates COP1-Mediated Degradation of HFR1, a Transcription Factor Essential for Light Signaling in Arabidopsis PLANT CELL, March 1, 2005; 17(3): 804 - 821. [Abstract] [Full Text] [PDF]

				S. Laubinger, K. Fittinghoff, and U. Hoecker The SPA Quartet: A Family of WD-Repeat Proteins with a Central Role in Suppression of Photomorphogenesis in Arabidopsis PLANT CELL, September 1, 2004; 16(9): 2293 - 2306. [Abstract] [Full Text] [PDF]

				M. Dieterle, C. Buche, E. Schafer, and T. Kretsch Characterization of a Novel Non-Constitutive Photomorphogenic cop1 Allele Plant Physiology, December 1, 2003; 133(4): 1557 - 1564. [Abstract] [Full Text]

				D.-S. Cho, S.-H. Hong, H.-G. Nam, and M.-S. Soh FIN5 Positively Regulates Far-red Light Responses in Arabidopsis thaliana Plant Cell Physiol., June 15, 2003; 44(6): 565 - 572. [Abstract] [Full Text] [PDF]

				J. O. Borevitz, J. N. Maloof, J. Lutes, T. Dabi, J. L. Redfern, G. T. Trainer, J. D. Werner, T. Asami, C. C. Berry, D. Weigel, et al. Quantitative Trait Loci Controlling Light and Hormone Response in Two Accessions of Arabidopsis thaliana Genetics, February 1, 2002; 160(2): 683 - 696. [Abstract] [Full Text] [PDF]

				T. Desnos, P. Puente, G. C. Whitelam, and N. P. Harberd FHY1: a phytochrome A-specific signal transducer Genes & Dev., November 15, 2001; 15(22): 2980 - 2990. [Abstract] [Full Text] [PDF]

				M. Zeidler, C. Bolle, and N.-H. Chua The Phytochrome A Specific Signaling Component PAT3 is a Positive Regulator of Arabidopsis Photomorphogenesis Plant Cell Physiol., November 1, 2001; 42(11): 1193 - 1200. [Abstract] [Full Text] [PDF]

				M. L. Ballesteros, C. Bolle, L. M. Lois, J. M. Moore, J.-P. Vielle-Calzada, U. Grossniklaus, and N.-H. Chua LAF1, a MYB transcription activator for phytochrome A signaling Genes & Dev., October 1, 2001; 15(19): 2613 - 2625. [Abstract] [Full Text] [PDF]

				H. Okamoto, L. Qu, and X.-W. Deng Does EID1 Aid the Fine-Tuning of Phytochrome A Signal Transduction in Arabidopsis? PLANT CELL, September 1, 2001; 13(9): 1983 - 1986. [Full Text] [PDF]

				A. E. Pepper, M.-s. Seong-Kim, S. M. Hebst, K. N. Ivey, S.-J. Kwak, and D. E. Broyles shl, a New Set of Arabidopsis Mutants with Exaggerated Developmental Responses to Available Red, Far-Red, and Blue Light Plant Physiology, September 1, 2001; 127(1): 295 - 304. [Abstract] [Full Text] [PDF]

				B. M. Parks, U. Hoecker, and E. P. Spalding Light-Induced Growth Promotion by SPA1 Counteracts Phytochrome-Mediated Growth Inhibition during De-Etiolation Plant Physiology, July 1, 2001; 126(3): 1291 - 1298. [Abstract] [Full Text] [PDF]

				M. Santiago-Ong, R. M. Green, S. Tingay, J. A. Brusslan, and E. M. Tobin shygrl1 Is a Mutant Affected in Multiple Aspects of Photomorphogenesis Plant Physiology, June 1, 2001; 126(2): 587 - 600. [Abstract] [Full Text] [PDF]

				S. G. Møller, T. Kunkel, and N.-H. Chua A plastidic ABC protein involved in intercompartmental communication of light signaling Genes & Dev., January 1, 2001; 15(1): 90 - 103. [Abstract] [Full Text]

				M.-S. Soh, Y.-M. Kim, S.-J. Han, and P.-S. Song REP1, a Basic Helix-Loop-Helix Protein, Is Required for a Branch Pathway of Phytochrome A Signaling in Arabidopsis PLANT CELL, November 1, 2000; 12(11): 2061 - 2074. [Abstract] [Full Text]

				C. D. Fairchild, M. A. Schumaker, and P. H. Quail HFR1 encodes an atypical bHLH protein that acts in phytochrome A signal transduction Genes & Dev., September 15, 2000; 14(18): 2377 - 2391. [Abstract] [Full Text]

				C. Fankhauser and J. Chory RSF1, an Arabidopsis Locus Implicated in Phytochrome A Signaling Plant Physiology, September 1, 2000; 124(1): 39 - 46. [Abstract] [Full Text]

				H.-L. Hsieh, H. Okamoto, M. Wang, L.-H. Ang, M. Matsui, H. Goodman, and X. W. Deng FIN219, an auxin-regulated gene, defines a link between phytochrome A and the downstream regulator COP1 in light control of Arabidopsis development Genes & Dev., August 1, 2000; 14(15): 1958 - 1970. [Abstract] [Full Text]

				E. Huq, J. M. Tepperman, and P. H. Quail GIGANTEA is a nuclear protein involved in phytochrome signaling in Arabidopsis PNAS, July 30, 2000; (2000) 170283997. [Abstract] [Full Text]

				P. D. Cerdán, R. J. Staneloni, J. Ortega, M. M. Bunge, M. J. Rodriguez-Batiller, R. A. Sánchez, and J. J. Casal Sustained but Not Transient Phytochrome A Signaling Targets a Region of an Lhcb1*2 Promoter Not Necessary for Phytochrome B Action PLANT CELL, July 1, 2000; 12(7): 1203 - 1212. [Abstract] [Full Text]

				C. Bolle, C. Koncz, and N.-H. Chua PAT1, a new member of the GRAS family, is involved in phytochrome A signal transduction Genes & Dev., May 15, 2000; 14(10): 1269 - 1278. [Abstract] [Full Text]

				J. F. Martínez-García, E. Huq, and P. H. Quail Direct Targeting of Light Signals to a Promoter Element-Bound Transcription Factor Science, May 5, 2000; 288(5467): 859 - 863. [Abstract] [Full Text]

				C. Lin Photoreceptors and Regulation of Flowering Time Plant Physiology, May 1, 2000; 123(1): 39 - 50. [Full Text]

				M. J. Yanovsky, G. C. Whitelam, and J. J. Casal fhy3-1 Retains Inductive Responses of Phytochrome A Plant Physiology, May 1, 2000; 123(1): 235 - 242. [Abstract] [Full Text]

				C. Büche, C. Poppe, E. Schäfer, and T. Kretsch eid1: A New Arabidopsis Mutant Hypersensitive in Phytochrome A-Dependent High-Irradiance Responses PLANT CELL, April 1, 2000; 12(4): 547 - 558. [Abstract] [Full Text]

				J. W. Reed, P. Nagpal, R. M. Bastow, K. S. Solomon, M. J. Dowson-Day, R. P. Elumalai, and A. J. Millar Independent Action of ELF3 and phyB to Control Hypocotyl Elongation and Flowering Time Plant Physiology, April 1, 2000; 122(4): 1149 - 1160. [Abstract] [Full Text]

				M. M. Neff, C. Fankhauser, and J. Chory Light: an indicator of time and place Genes & Dev., February 1, 2000; 14(3): 257 - 271. [Full Text]

				D. Cao, Y. Lin, and C.-L. Cheng Genetic Interactions between the Chlorate-Resistant Mutant cr 8 8 and the Photomorphogenic Mutants cop1 and hy5 PLANT CELL, February 1, 2000; 12(2): 199 - 210. [Abstract] [Full Text]

				N. Kuno, T. Muramatsu, F. Hamazato, and M. Furuya Identification by Large-Scale Screening of Phytochrome-Regulated Genes in Etiolated Seedlings of Arabidopsis Using a Fluorescent Differential Display Technique Plant Physiology, January 1, 2000; 122(1): 15 - 24. [Abstract] [Full Text] [PDF]

				M. Hudson, C. Ringli, M. T. Boylan, and P. H. Quail The FAR1 locus encodes a novel nuclear protein specific to phytochrome A signaling Genes & Dev., August 1, 1999; 13(15): 2017 - 2027. [Abstract] [Full Text]

				K. J. Halliday, M. Hudson, M. Ni, M. Qin, and P. H. Quail poc1: An Arabidopsis mutant perturbed in phytochrome signaling because of a T DNA insertion in the promoter of PIF3, a gene encoding a phytochrome-interacting bHLH protein PNAS, May 11, 1999; 96(10): 5832 - 5837. [Abstract] [Full Text] [PDF]

				A. C. Mustilli, F. Fenzi, R. Ciliento, F. Alfano, and C. Bowler Phenot ype of the Tomato high pigment-2 Mutant Is Caused by a Mutation in the Tomato Homolog of DEETIOLATED1 PLANT CELL, February 1, 1999; 11(2): 145 - 158. [Abstract] [Full Text]

				J. L. Peters, M. Széll, and R. E. Kendrick The Expression of Light-Regulated Genes in the High-Pigment-1 Mutant of Tomato Plant Physiology, July 1, 1998; 117(3): 797 - 807. [Abstract] [Full Text]

				C. B. Taylor SPA-rring Partner for Phytochrome A? PLANT CELL, January 1, 1998; 10(1): 1 - 3. [Full Text]

				U. Hoecker and P. H. Quail The Phytochrome A-specific Signaling Intermediate SPA1 Interacts Directly with COP1, a Constitutive Repressor of Light Signaling in Arabidopsis J. Biol. Chem., October 5, 2001; 276(41): 38173 - 38178. [Abstract] [Full Text] [PDF]

				E. Huq, J. M. Tepperman, and P. H. Quail GIGANTEA is a nuclear protein involved in phytochrome signaling in Arabidopsis PNAS, August 15, 2000; 97(17): 9789 - 9794. [Abstract] [Full Text] [PDF]

				Y.-C. Zhou, M. Dieterle, C. Buche, and T. Kretsch The Negatively Acting Factors EID1 and SPA1 Have Distinct Functions in Phytochrome A-Specific Light Signaling Plant Physiology, March 1, 2002; 128(3): 1098 - 1108. [Abstract] [Full Text] [PDF]