FLORIGENE · Characterization of the role of the FLOWERING LOCUS T mRNA transport in the regulation of flowering time
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2006-11-01 → 2007-10-31
- EU contribution
- €158,016
- Participants
- 1
- Scheme
- EIF
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Results in brief
Final Activity Report Summary - FLORIGENE (Characterisation of the role of the flowering locus T mRNA transport in the regulation of flowering time)
This project was aimed at characterising the role of the mRNA from the Arabidopsis gene FT as the possible signal that moves from leaf to shoot apex to induce flowering, the so called "FLORIGEN". The project was based on a previously published report showing that when FT expression was induced in a single Arabidopsis leaf, the FT mRNA could move from leaf to shoot apex, presumably leading to the induction of flowering. However, during the cause of this project it was shown that this previous report was based on incorrect data handling, and when data was correctly analysed no proof of FT mRNA movement could be found. The previously published experiments were also repeated, and again no mRNA FT transport could be detected. Taken together, this work showed convincingly that there is no support for the notion of the FT mRNA serving as the "Florigen". During this project also other aspects of FT function and regulation were investigated. It was found that although the FT gene has a very strong expression in the siliques during seed formation, no evidence for a role of FT in the regulation of seed dormancy or germination could be found. Aditionally, experiments were initiated to study the role of the plant Mediator complex in the transcriptional regulation of FT.
Data: CORDIS, © European Union
Project objective
The regulation of plant flowering time is a highly adaptive trait. Plants must integrate a multitude of environmental and internal signals in order to flower at the right time of the year. One of the most important factors regulating flowering time is the length of the day, where some plants, like Arabidopsis, respond to a lengthening of the day in order to flower in the spring. Since the 1930s it has been clear that the day-length regulation of flowering time is controlled by a substance moving from the leaf to the shoot apex where the initiation of flower primordia takes place. This substance was called florigen. However, during the last couple of years several important breakthroughs have occurred for our understanding of the day-length regulation of flowering time which has now lead to the identification of a possible identity of florigen as the mRNA produced by the gene FLOWERING LOCUS T (FT). Using a system allowing heat-shock inducible expression of FT in a single Arabidopsis leaf, we could show that the FT mRNA moves from the leaf to the shoot apex where it induces downstream targets.We could also show that FT induces other targets in the leaf, including an autoregulation of its own transcription, and that ultimately the endogenous FT gene is also induced in the shoot apex. Together, these data showed that the FT mRNA fulfilled all the criteria associated with the classical florigen molecule, although, at the time we could not exclude that also the FT protein moves. This finding has lead to a completely new view of the mechanism regulating flowering time, and prompts a whole new set of experiments in order to further characterize the activity of FT and the possible regulation of the FT mRNA transport.
Original text from CORDIS.
Participants
- THE SWEDISH UNIVERSITY OF AGRICULTURAL SCIENCES · UPPSALACoordinatorSweden
Links
Data: CORDIS, © European Union