Deciphering spatio-temporal functions of FT florigen during flower and inflorescence development

Obiettivo

In many temperate plant species, environmental cues such as daylength or photoperiod regulate crucial developmental processes, including the transition to flowering. This flowering response is controlled by a systemic signal generated in leaves and transported to the shoot apex. In Arabidopsis, FLOWERING LOCUS T (FT) is a major component of this signal, and its role in promoting flowering seems to be highly conserved across all flowering plants. Recent discoveries reveal FT is also transcribed locally in floral primordia, suggesting it has additional roles in flower development and organ identity regulation. The aims of this project are to elucidate the spatio-temporal expression, regulatory mechanisms, and functional significance of FT in Arabidopsis floral primordia, and to compare these with the canonical knowledge of FT in leaves. Using advanced confocal microscopy, RNA in situ hybridization, and quantitative imaging, I will generate a comprehensive profile of FT transcript and protein expression across all developmental stages from primordium initiation to floral meristem termination. I will then investigate FT regulation and function relative to other key floral regulators known to define the adaxial and abaxial boundaries of the floral primordium. This will be achieved by crossing FT reporter line with relevant mutants. Finally, I will identify direct FT targets and interacting proteins in flowers through CUT&TAG, RNA sequencing, and immunoprecipitation-mass spectrometry using a dexamethasone-inducible floral induction system. This work will significantly advance understanding of FT beyond flowering time control, and reveal its broader functions in floral organogenesis. Insights gained will refine models of flower development in Arabidopsis and provide a framework to explore FT roles in diverse species, including crops, with implications for plant breeding and agriculture.