Supplemental Experimental Procedures Table S1. Flowering Time of Plants Over-Expressing a Genomic Clone of UFC

Plant Linea Flowering TimebInsertion of a Ds element within the first intron of the gene gave rise to the flc-20 mutant in the ecotype C24; FLC is transcribed but lacks C24 22.0 0.9 detectable full-length FLC transcripts and FLC protein. The flc-11 UFC #1 20.4 0.6 mutant, also in the C24 background, was identified as a late-flow- UFC #5 21.1 0.6 ering mutant [S1]. This mutant has an enhanced vernalization re- UFC #7 22.6 0.5 quirement; it needs an 8 week cold treatment to cause significant UFC #8 22.0 0.6 promotion of flowering and downregulation of FLC [S1]. The acces-sion of Pitztal is as described in Sheldon et al. [S1]. The FLC::GUS a The expression levels of UFC are shown in Figure 1G. b Leaf number at flowering standard error.transgenic lines are those described in Sheldon et al. [S2], and the METI antisense plants were homozygous plants from line 10.5 [S3]. Plant Transformation Supplemental References Plants were transformed by the dipping method [S4], and transgeni