FD Net · Deciphering different layers of regulation of FLOWERING LOCUS D, a bZIP transcription factor that promotes flowering of Arabidopsis
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-09-01 → 2023-08-31
- EU contribution
- €174,806
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Deciphering different layers of regulation of FLOWERING LOCUS D, a bZIP transcription factor that promotes flowering of Arabidopsis
Floral transition is a crucial step in the plant life cycle, and is controlled by multiple endogenous and environmental cues such as photoperiod, temperature, hormones and sugars. The timing of floral transition affects the reproductive success of the plant by influencing several downstream traits such as plant architecture, yield and effective seed dispersal. Flowering plants dominate terrestrial ecosystems and are a major source of food for human society. Thus, understanding how plants regulate flowering is essential to secure food production, as the detrimental effects of global warming on agriculture are already visible. Arabidopsis has been widely used as a model system to decipher the genetic pathways controlling floral transition, especially in response to photoperiod. Under long-day conditions (LD), transcription of FLOWERING LOCUS T (FT) is induced in leaf phloem companion cells and the FT protein is transported to the shoot apical meristem to initiate floral development. In the meristem, FT-mediated activation of flowering-time and floral-meristem identity genes requires the interaction of FT with the basic leucine zipper (bZIP) transcription factor FD. Recently, a growing body of evidence supports the idea that FD performs other functions in plant development in addition to its role in floral transition. The overall objective of the Action was to decipher different layers of regulation of FD, which would reveal different modes of action of FD during plant development. For this, the FD phosphorylation status, its protein interactome, and its relationship with two group A bZIP transcription factors were investigated. In conclusion, the results obtained during this Action have advanced our knowledge of how photoperiod regulates different developmental processes through an intricate network composed of FT, FD and several group A bZIP transcription factors.
Data: CORDIS, © European Union
Project objective
Floral transition denotes the initiation of plant reproduction. Several genetic pathways regulate this important transition and many of them converge on the regulation of FLOWERING LOCUS T (FT), the systemic flowering signal that moves from leaves to the shoot apex. FT reprograms transcription at the shoot apex by contributing to Florigen Activation Complex (FAC). A central component of this complex is the bZIP transcription factor FLOWERING LOCUS D (FD), which is responsible for DNA binding and gene specific regulation by the complex. I will employ single-cell RNA sequencing to capture the transient cell state where the FAC complex and two different target genes, APETALA1 and SOC1, are coexpressed. Defining the transcriptomic network of FD at the single-cell level will provide a deeper understanding of this dynamic process. Phosphorylation of a threonine residue in the SAP motif at the C terminus of FD is a key step in formation of the complex. Phosphomimetic or non-phosphorylatable FD SAP motif versions have opposite effects on FD function, being able or not, respectively, to complement the late flowering phenotype of fd-3. I will investigate whether SAP motif phosphorylation affects FD protein stability or impairs its protein-protein interactions using confocal microscopy and protein mass spectrometry. In addition, other bZIPs closely related to FD are phosphorylated at other sites, but no analysis of FD phosphorylation sites other than the SAP motif has been presented. I will map post-translational modifications of FD, which may reveal new regulatory steps in controlling FD activity. I will explore the ability of FD to form protein complexes with other transcription factors by employing yeast-two hybrid, protein pull-downs and interaction studies using immunoprecipitation-mass spectrometry and biotin-based proximity labeling. The identification of new FD protein interactors will start reverse genetic and biochemical approaches to better understand FD function.
Original text from CORDIS.
Participants
- MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV · MUNCHENCoordinatorGermany
Links
Data: CORDIS, © European Union