Plant development continues post-embryonically throughout the life of the plant, and environmental conditions have a large influence on plant architecture and the timing of the switch from vegetative to reproductive growth. We could show that a key factor involved in transmitting environmental Information within the plant is FT. FT" is expressed in the leaf vasculature in response to floral inductive cues. FT protein is then transported through the vasculature to the shoot apex, where it builds an activating complex with the transcription factor FD to promote flowering. In this way FT expression provides temporal information, while the spatial information of where flowers are to be made is provided by the expression domain of FD.