Isolation and Expression Profiling of a CONSTANS-Like Gene and Two FLOWERING LOCUS T-Like Genes from Spinacia oleracea L.


Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that bolts easily with a shorter photoperiod than European spinach. This is one of the main reasons that Oriental spinach is difficult to grow year-round. In order to understand spinach flowering mechanisms and obtain knowledge for spinach breeding, we isolated one CONSTANS-like (COL) and two FLOWERING LOCUS T (FT) homologs, which are key components of photoperiodic regulation of flowering time, from a Japanese cultivar. The expression of SoCOL1 showed diurnal rhythm with the highest expression at the end of the dark cycle. This diurnal rhythm is similar to the expression of BvCOL1 from sugar beet (Beta vulgaris), whose flower-promoting effect was observed when overexpressed in Arabidopsis. Phylogenetic analysis showed that SoCOL1 is the closest homolog of BvCOL1, suggesting that SoCOL1 is an ortholog of BvCOL1. SoFT1 and SoFT2 are closely related to BvFT1 and BvFT2, respectively. The expression of SoFT1 and SoFT2 were induced in advance of flower bud formation after changing the photoperiod, but the expression level of SoFT1 was much lower than SoFT2. Currently, we are speculating that SoFT2 is a flower-promoting factor of spinach, and that SoFT1 has a role in light signaling because the expression of SoFT1 showed a diurnal rhythm.

Share and Cite:

Abe, E. , Fujino, K. , Masuda, K. and Yamaguchi, Y. (2014) Isolation and Expression Profiling of a CONSTANS-Like Gene and Two FLOWERING LOCUS T-Like Genes from Spinacia oleracea L.. American Journal of Plant Sciences, 5, 4018-4028. doi: 10.4236/ajps.2014.526420.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Kagawa, A. (1974) Horenso: Nougyougijutsutaikei. Nobunkyou, Tokyo, Vol. 7, 3-8.
[2] Zeevaart, J.A. (2008) Leaf-Produced Floral Signals. Current Opinion in Plant Biology, 11, 541-547.
[3] Song, Y.H., Ito, S. and Imaizumi, T. (2013) Flowering Time Regulation: Photoperiod- and Temperature-Sensing in Leaves. Trends in Plant Science, 18, 575-583.
[4] Ballerini, E.S. and Kramer, E.M. (2011) In the Light of Evolution: A Reevaluation of Conservation in the CO-FT Regulon and Its Role in Photoperiodic Regulation of Flowering Time. Frontiers in Plant Science, 2, 81.
[5] Griffiths, S., Dunford, R.P., Coupland, G. and Laurie, D.A. (2003) The Evolution of CONSTANS-Like Gene Families in Barley, Rice, and Arabidopsis. Plant Physiology, 131, 1855-1867.
[6] Valverde, F. (2011) CONSTANS and the Evolutionary Origin of Photoperiodic Timing of Flowering. Journal of Experimental Botany, 62, 2453-2463.
[7] Tiwari, S.B., Shen, Y., Chang, H.C., Hou, Y., Harris, A., Ma, S.F., McPartland, M., Hymus, G.J., Adam, L., Marion, C., Belachew, A., Repetti, P.P., Reuber, T.L. and Ratcliffe, O.J. (2010) The Flowering Time Regulator CONSTANS Is Recruited to the FLOWERING LOCUS T Promoter via a Unique cis-Element. New Phytologist, 187, 57-66.
[8] Yamaguchi, A., Kobayashi, Y., Goto, K., Abe, M. and Araki, T. (2005) TWIN SISTER OF FT (TSF) Acts as a Floral Pathway Integrator Redundantly with FT. Plant and Cell Physiology, 46, 1175-1189.
[9] Abe, M., Kobayashi, Y., Yamamoto, S., Daimon, Y., Yamaguchi, A., Ikeda, Y., Ichinoki, H., Notaguchi, M., Goto, K. and Araki, T. (2005) FD, a bZIP Protein Mediating Signals from the Floral Pathway Integrator FT at the Shoot Apex. Science, 309, 1052-1056.
[10] Kobayashi, Y., Kaya, H., Goto, K., Iwabuchi, M. and Araki, T. (1999) A Pair of Related Genes with Antagonistic Roles in Mediating Flowering Signals. Science, 286, 1960-1962.
[11] Pin, P.A., Benlloch, R., Bonnet, D., Wremerth-Weich, E., Kraft, T., Gielen, J.J. and Nilsson, O. (2010) An Antagonistic Pair of FT Homologs Mediates the Control of Flowering Time in Sugar Beet. Science, 330, 1397-1400.
[12] Zeevaart, J.A. (1971) Effects of Photoperiod on Growth Rate and Endogenous Gibberellins in the Long-Day Rosette Plant Spinach. Plant Physiology, 47, 821-827.
[13] Wu, K., Li, L., Gage, D.A. and Zeevaart, J.A. (1996) Molecular Cloning and Photoperiod-Regulated Expression of Gibberellin 20-Oxidase from the Long-Day Plant Spinach. Plant Physiology, 110, 547-554.
[14] Lee, D.J. and Zeevaart, J.A. (2002) Differential Regulation of RNA Levels of Gibberellin Dioxygenases by Photoperiod in Spinach. Plant Physiology, 130, 2085-2094.
[15] Lee, D.J. and Zeevaart, J.A. (2005) Molecular Cloning of GA2-Oxidase3 from Spinach and Its Ectopic Expression in Nicotiana sylvestris. Plant Physiology, 138, 243-254.
[16] Lee, D.J. and Zeevaart, J.A. (2007) Regulation of Gibberellin 20-Oxidase1 Expression in Spinach by Photoperiod. Planta, 226, 35-44.
[17] Chia, T.Y., Müller, A., Jung, C. and Mutasa-Göttgens, E.S. (2008) Sugar Beet Contains a Large CONSTANS-LIKE Gene Family Including a CO Homologue That Is Independent of the Early-Bolting (B) Gene Locus. Journal of Experimental Botany, 59, 2735-2748.
[18] Chab, D., Kolar, J., Olson, M.S. and Storchova, H. (2008) Two FLOWERING LOCUS T (FT) Homologs in Chenopodium rubrum Differ in Expression Patterns. Planta, 228, 929-940.
[19] Drabešová, J., Cháb, D., Kola?, J., Haškovcová, K. and Štorchová, H. (2014) A Dark-Light Transition Triggers Expression of the Floral Promoter CrFTL1 and Downregulates CONSTANS-Like Genes in a Short-Day Plant Chenopodium rubrum. Journal of Experimental Botany, 65, 2137-2146.
[20] Kawade, K., Ishizaki, T. and Masuda, K. (2008) Differential Expression of Ribosome-Inactivating Protein Genes during Somatic Embryogenesis in Spinach (Spinacia oleracea). Physiologia Plantarum, 134, 270-281.
[21] Hanzawa, Y., Money, T. and Bradley, D. (2005) A Single Amino Acid Converts a Repressor to an Activator of Flowering. Proceedings of the National Academy of Sciences of the United States of America, 102, 7748-7753.
[22] Ahn, J.H., Miller, D., Winter, V.J., Banfield, M.J., Lee, J.H., Yoo, S.Y., Henz, S.R., Brady, R.L. and Weigel, D. (2006) A Divergent External Loop Confers Antagonistic Activity on Floral Regulators FT and TFL1. The EMBO Journal, 25, 605-614.
[23] Ho, W.W. and Weigel, D. (2014) Structural Features Determining Flower-Promoting Activity of Arabidopsis FLOWERING LOCUS T. Plant Cell, 26, 552-564.
[24] Ledger, S., Strayer, C., Ashton, F., Kay, S.A. and Putterill, J. (2001) Analysis of the Function of Two Circadian- Regulated CONSTANS-LIKE Genes. The Plant Journal, 26, 15-22.
[25] Suarez-Lopez, P., Wheatley, K., Robson, F., Onouchi, H., Valverde, F. and Coupland, G. (2001) CONSTANS Mediates between the Circadian Clock and the Control of Flowering in Arabidopsis. Nature, 410, 1116-1120.
[26] Wang, C.Q., Guthrie, C., Sarmast, M.K. and Dehesh, K. (2014) BBX19 Interacts with CONSTANS to Repress FLOWERING LOCUS T Transcription, Defining a Flowering Time Checkpoint in Arabidopsis. Plant Cell, 21, 3416-3420.
[27] Dally, N., Xiao, K., Holtgräwe, D. and Jung, C. (2014) The B2 Flowering Time Locus of Beet Encodes a Zinc Finger Transcription Factor. Proceedings of the National Academy of Sciences of the United States of America, 111, 10365- 10370.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.