Identification of interactors of Arabidopsis VIN3 and VRN5 proteins in vernalized seedlings

The Arabidopsis VEL proteins VIN3 and VRN5 are accessory proteins of the Polycomb Repressive Complex 2 (PRC2). Their function is most well-understood in the epigenetic PRC2-mediated silencing of the floral repressor gene Flowering Locus C (FLC) during prolonged cold (vernalization). To identify protein interactors of VIN3 and VRN5, also dependent on their C-terminal VEL domains, we used stable Arabidopsis transgenic lines expressing VIN3-GFP WT, VIN3-GFP deltaVEL, VRN5-SYFP2 WT and VRN5-SYFP2 deltaVEL under endogenous promoters to perform native co-immunoprecipitation assays in seedlings vernalized for six weeks at 5 °C. Non-transgenic Col-FRI was used as a negative control.