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Review
. 2002;14 Suppl(Suppl):S111-30.
doi: 10.1105/tpc.001362.

Control of flowering time: interacting pathways as a basis for diversity

Aidyn Mouradov  1 , Frédéric Cremer, George Coupland
Affiliations
Review

Control of flowering time: interacting pathways as a basis for diversity

Aidyn Mouradov et al. Plant Cell. 2002.
No abstract available

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Figures

Figure 1.
Figure 1.
Signaling Pathways Involved in the Regulation of Flowering by Photoperiod in Arabidopsis. A diagram showing the putative relationships among genes involved in the photoperiod pathway. On the basis of the phenotypes of known mutants, genes shown in red generally repress flowering, whereas those in green promote it. Small upright arrows indicate the role of the genes as determined by overexpression in transgenic plants. Arrows between genes represent a promotive effect, whereas perpendicular lines represent a repressive effect, and simple lines represent protein–protein interactions. Arrows from the clock indicate that the expression of the gene is circadian clock controlled. Arrows to the clock indicate that the gene lengthens period length, while perpendicular lines indicate that it shortens period length. Numbers between brackets refer to the following publications, which support the indications provided in the diagram. (1) (Somers et al., 1998b) (2) (Swarup et al., 1999) (3) (Wang and Tobin, 1998) (4) (Schaffer et al., 1998) (5) (Mizoguchi et al., 2002) (6) (Goto et al., 1991) (7) (Samach et al., 2000) (8) (Onouchi et al., 2000) (9) (Alabadi et al., 2001) (10) (Strayer et al., 2000) (11) (Martinez-Garcia et al., 2000) (12) (Nelson et al., 2000) (13) (Jarillo et al., 2001) (14) (Millar et al., 1995a) (15) (Somers et al., 2000) (16) (Sugano et al., 1999) (17) (Zagotta et al., 1992) (18) (Sugano et al., 1998) (19) (Liu et al., 2001b) (20) (Hicks et al., 2001) (21) (Covington et al., 2001) (22) (Fowler et al., 1999) (23) (Park et al., 1999) (24) (Fowler et al., 1999; Park et al., 1999) (25) (Johnson et al., 1994) (26) (Bagnall et al., 1995) (27) (Guo et al., 1998) (28) (Putterill et al., 1995) (29) (Simon et al., 1996) (30) (Mozley and Thomas, 1995) (31) (Ahmad et al., 1998) (32) (Koornneef et al., 1980) (33) (Suarez-Lopez et al., 2001) (34) (Somers et al., 1998a).
Figure 2.
Figure 2.
The Effects of Vernalization and the Autonomous Pathway on Flowering Time, Emphasizing the Central Role of FLC. The autonomous pathway genes and vernalization promote flowering by repressing FLC expression. Once FLC expression is reduced by vernalization, it is stably repressed by the VRN2 gene product. Vernalization promotes flowering independently of FLC as well as by FLC repression. HOS1 seems to act as a repressor of the vernalization pathway. FLC expression is promoted by FRI. FLC represses flowering and, at least in part, this occurs through repressing the flowering time genes SOC1 and FT. The data used to derive this model are described in detail in the text.
Figure 3.
Figure 3.
GA-Signaling Pathway That Regulates Flowering in Arabidopsis. Activation of a hypothetical transmembrane receptor by GA inhibits repressors of GA signaling. These repressors are encoded by the RGA, GAI, and RGL genes. The SPY gene also represses GA signaling and genetically acts upstream of RGA and GAI. It may act to promote the activity of GAI/RGA/RGL by GlcNAc modification, in which case GA signaling may inhibit GAI/RGA/RGAL by repressing SPY function. PHOR1 has not been described in Arabidopsis, but has been shown to be involved in GA signaling in potato. Its possible involvement in ubiquitination and protein degradation leads to the tentative proposal that it is involved in the demonstrated degradation of the repressing protein RGA in response to GA. The floral meristem identity gene LFY is upregulated at the transcriptional level by GA. The flowering-time gene SOC1 is also upregulated by GA, whereas FPF1 and GA-MYB were proposed to mediate between GAs and the regulation of flowering time. These three genes may therefore act downstream of GAI/RGA/RGL but upstream of LFY. The data underlying this scheme are described in detail in the text.
Figure 4.
Figure 4.
Overview of the Relationships among Arabidopsis Flowering Pathways. The pathways described in detail in Figures 1 to 3 are combined to emphasize their relationships. In particular, the effects of the integration of the photoperiod, GA, and vernalization pathways on the regulation of expression of FT and SOC1 is illustrated. The data underlying this model are described in detail in the text.
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References

    1. Adams, J., Kelso, R., and Cooley, L. (2000). The kelch repeat superfamily of proteins: Propellers of cell function. Trends Cell Biol. 10 17–24. - PubMed
    1. Ahmad, M., Jarillo, J.A., and Cashmore, A.R. (1998). Chimeric proteins between cry1 and cry2 Arabidopsis blue light photoreceptors indicate overlapping functions and varying protein stability. Plant Cell 10 197–207. - PMC - PubMed
    1. Alabadi, D., Oyama, T., Yanovsky, M.J., Harmon, F.G., Mas, P., and Kay, S.A. (2001). Reciprocal regulation between TOC1 and LHY/CCA1 within the Arabidopsis circadian clock. Science 293 880–883. - PubMed
    1. Amador, V., Monte, E., Garcia-Martinez, J.L., and Prat, S. (2001). Gibberellins signal nuclear import of PHOR1, a photoperiod-responsive protein with homology to Drosophila armadillo. Cell 106 343–354. - PubMed
    1. Araki, T. (2001). Transition from vegetative to reproductive phase. Curr. Opin. Plant Biol. 4 63–68. - PubMed

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