A Short History of florigen, - The identity of florigen remains one of the major mysteries in plant biology. In 1865, Sachs observed that leaves in the light produce flower-forming substances , which are present in small quantities and lead to the formation of flowers.
(From Hoffmann-Benning et al., Planta 216:140—147, 2002)
Researchers at the Umea Plant Science Centre in Sweden and the Universite Joseph Fourier in France have identified the messenger RNA for the flowering locus T (FT) gene as the elusive “florigen” signaling compound, appears to be this trigger for initiation of flowering.
The group constructed transgenic plants expressing the FT gene and the marker gene GUS under control of a heat-shock inducible promoter (Hsp) from soybean as well as the FT promoter (pFT). When microdissected plant tissues, whole plants or individual leaves were subjected to heating, gene expression levels could be monitored throughout the plants.
In this way they were able to follow expression levels of FT in various tissues and confirm movement of the FT-induced signal from leaf to apex tissues.
- Huang, T., Bohlenius, H., Eriksson, S., Parcy, F., Nilsson, O., (2005) “The mRNA of the Arabidopsis Gene FT Moves front Leaf to Shoot Apex and Induces Flowering” Science 309(5741):
- Abe,M. Kobayashi, Y., Yamamoto, S., Daimon, Y., Yamaguchi, A., Ikeda, Y., Ichinoki, H., Notaguchi, M., Goto, K., Araki, T.., (2005)“FD, a bZIP Protein Mediating Signals from the Floral Pathway Integrator FT at the Shoot Apex” Science, 309(5737): 1052-1056.
- Wigge, P.A., Kim, M.C., Jaeger, K.E., Busch, W., Markus Schmid,M., Lohmann, J.U., Weigel, D., (2005)“Integration of Spatial and Temporal Information During Floral Induction in Arabidopsis”Science 309(5737): 1056-1059.
- Hoffmann-Benning, S., Zeevaart, J.A.D. “Searching for Florigen” Plant Physiology Online 24:2 (2003) http://www.plantphys.net/article.php?ch=e&id=288
- Ayre, B.G., “Florigen and a Genetic Approach to Long-Distance Signaling Through the Phloem” Plant Physiology Online 24:3 (2005) http://www.plantphys.net/article.php?ch=e&id=291
- Miguel A. Blázquez (2005) “The Right Time and Place for Making Flowers” Science 309 (5737): 1024-1025.
Plant “Florigen” factor identified.