title: Diversification of photoperiodic response patterns in a collection of early-flowering mutants of Arabidopsis.
abstract: Many plant species exhibit seasonal variation of flowering time in response to daylength. Arabidopsis (Arabidopsis thaliana) flowers earlier under long days (LDs) than under short days (SDs). This quantitative response to photoperiod is characterized by two parameters, the critical photoperiod (Pc), below which there is a delay in flowering, and the ceiling photoperiod (Pce), below which there is no further delay. Thus Pc and Pce define the thresholds beyond which maximum LD and SD responses are observed, respectively. We studied the quantitative response to photoperiod in 49 mutants selected for early flowering in SDs. Nine of these mutants exhibited normal Pce and Pc, showing that their precocious phenotype was not linked to abnormal measurement of daylength. However, we observed broad diversification in the patterns of quantitative responses in the other mutants. To identify factors involved in abnormal measurement of daylength, we analyzed the association of these various patterns with morphogenetic and rhythmic defects. A high proportion of mutants with altered Pce exhibited abnormal hypocotyl elongation in the dark and altered circadian periods of leaf movements. This suggested that the circadian clock and negative regulators of photomorphogenesis may contribute to the specification of SD responses. In contrast, altered Pc correlated with abnormal hypocotyl elongation in the light and reduced photosynthetic light-input requirements for bolting. This indicated that LD responses may be specified by positive elements of light signal transduction pathways and by regulators of resource allocation. Furthermore, the frequency of circadian defects in mutants with normal photoperiodic responses suggested that the circadian clock may regulate the number of leaves independently of its effect on daylength perception.
authors.affiliation: UR Biologie Cellulaire, INRA, F78026 Versailles, France. sylvie.pouteau@versailles.inra.fr
authors.forename: Sylvie
authors.initials: S
authors.lastname: Pouteau
authors.forename: Isabelle
authors.initials: I
authors.lastname: Carré
authors.forename: Valérie
authors.initials: V
authors.lastname: Gaudin
authors.forename: Valérie
authors.initials: V
authors.lastname: Ferret
authors.forename: Delphine
authors.initials: D
authors.lastname: Lefebvre
authors.forename: Melanie
authors.initials: M
authors.lastname: Wilson
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D035264:Flowers; D009024:Morphogenesis; D009154:Mutation; D017440:Photoperiod
references.citation: Plant Cell. 2007 Nov;19(11):3462-73
references.pmid: 18055606
references.citation: Plant Cell. 2001 Jun;13(6):1281-92
references.pmid: 11402160
references.citation: Development. 2006 Aug;133(16):3213-22
references.pmid: 16854975
references.citation: Plant Physiol. 2002 Aug;129(4):1674-85
references.pmid: 12177480
references.citation: Plant Cell. 2007 Oct;19(10):2988-3000
references.pmid: 17965272
references.citation: Development. 2001 Dec;128(23):4847-58
references.pmid: 11731464
references.citation: Plant Biotechnol J. 2005 Jan;3(1):3-16
references.pmid: 17168895
references.citation: Plant J. 2002 Feb;29(4):427-37
references.pmid: 11846876
references.citation: EMBO J. 2008 Apr 23;27(8):1277-88
references.pmid: 18388858
references.citation: Plant Cell Physiol. 2001 Oct;42(10):1025-33
references.pmid: 11673616
references.citation: Biotechniques. 2001 Mar;30(3):496-8, 502, 504
references.pmid: 11252785
references.citation: Int J Plant Sci. 1999 Nov;160(S6):S123-S134
references.pmid: 10572027
references.citation: Plant Cell. 2001 Jun;13(6):1305-15
references.pmid: 11402162
references.citation: Plant Physiol. 2007 Feb;143(2):941-58
references.pmid: 17208962
references.citation: Plant Physiol. 2008 Apr;146(4):1482-500
references.pmid: 18263779
references.citation: Nucleic Acids Res. 2002 Jan 1;30(1):94-7
references.pmid: 11752264
references.citation: Ann Bot. 2005 Aug;96(2):169-75
references.pmid: 15894550
references.citation: Plant Cell. 2004 Nov;16(11):2940-53
references.pmid: 15472079
references.citation: Proc Natl Acad Sci U S A. 2005 Feb 15;102(7):2460-5
references.pmid: 15695584
references.citation: Nature. 2001 Apr 26;410(6832):1116-20
references.pmid: 11323677
references.citation: Proc Natl Acad Sci U S A. 2002 Oct 1;99(20):13313-8
references.pmid: 12271123
references.citation: Plant J. 2007 Jun;50(6):1007-19
references.pmid: 17521410
references.citation: Plant Physiol. 2004 May;135(1):201-11
references.pmid: 15122022
references.citation: Bioessays. 2004 Apr;26(4):363-73
references.pmid: 15057934
references.citation: Nat Rev Mol Cell Biol. 2003 Apr;4(4):265-75
references.pmid: 12671649
references.citation: Science. 1996 Nov 1;274(5288):790-2
references.pmid: 8864121
references.citation: Development. 2004 Aug;131(15):3615-26
references.pmid: 15229176
references.citation: Plant Cell. 2008 Feb;20(2):292-306
references.pmid: 18296627
references.citation: J Exp Bot. 2006;57(15):4099-109
references.pmid: 17110584
references.citation: Science. 2004 Feb 13;303(5660):1003-6
references.pmid: 14963328
references.citation: Nature. 2002 Sep 19;419(6904):308-12
references.pmid: 12239570
references.citation: Science. 2005 Jul 22;309(5734):630-3
references.pmid: 16040710
references.citation: Plant J. 1999 Jan;17(1):63-71
references.pmid: 10069068
references.citation: Annu Rev Plant Biol. 2004;55:141-72
references.pmid: 15377217
references.citation: Plant Cell. 2008 Feb;20(2):307-19
references.pmid: 18281507
references.citation: Nature. 2002 Sep 5;419(6902):74-7
references.pmid: 12214234