FVE coordinates with COP1 to modulate flowering time at low ambient temperature

Area of Science:

• Plant Biology
• Molecular Biology
• Genetics

Background:

• Plants delay flowering under low ambient temperatures to optimize reproductive success.
• The WD40 protein FVE is known to regulate histone acetylation and flowering time.
• The precise mechanism by which FVE responds to low temperatures to modulate flowering remains unclear.

Purpose of the Study:

• To investigate the role of FVE in regulating Arabidopsis flowering time at low ambient temperatures.
• To elucidate the molecular interactions and pathways through which FVE functions under cold conditions.

Main Methods:

• Genetic analysis of Arabidopsis thaliana mutants (fve, svp, cop1).
• Protein-protein interaction studies (in vitro and in vivo).
• Chromatin immunoprecipitation (ChIP) to assess histone modifications (H3K9ac) and protein occupancy at the FT locus.

Main Results:

• Loss of FVE function leads to late flowering at low temperatures, with flowering time less sensitive to temperature changes.
• FVE forms a complex with SVP and FLM-β, and FVE's occupancy at the FT locus is dependent on SVP.
• FVE removes H3K9ac marks at the FT locus.
• COP1 interacts with FVE, promoting its ubiquitination and degradation; loss of COP1 increases FVE levels and reduces H3K9ac at FT.

Conclusions:

• FVE plays a critical role in temperature-mediated flowering time control in Arabidopsis.
• FVE functions by forming a complex with SVP and FLM-β to regulate histone acetylation at the FT locus.
• COP1 negatively regulates FVE activity, linking light signaling and temperature responses in flowering time control.