Classification of L er -specific H3K27me3 targets based on their expression. (a) Expression pattern of Ler-specific H3K27me3 targets in Col in different tissues. The expression value was normalized to the mean of all genes within each sample. Five expressed Ler-specific targets (Exp_Col) are framed in red. The developmental stages and tissues used for experiments are: roots at 7 days (Ro); seedlings, aerial parts, 7 days (Se7); expanding leaves, 10 days (Le10); senescing leaves, 35 days (Le35); stem, 2nd internode (St); vegetative shoot meristem, 7 days (Me7); inflorescence shoot meristem, 21 days (Inf21); whole inflorescences to floral stage 9, 21 days (Me21); whole inflorescences of clavata3-7 mutants, 21 days (clv); flowers, stage 15, 21+ days (Fl21); fruits, carpels stage 15, 21+ days (Fr21). The data were obtained from the Arabidopsis thaliana Tiling Array Express (At-TAX) resource . (b) Expression pattern of Ler-specific targets in 19 Arabidopsis accessions. Accessions indicated below the heatmap are Columbia-0 (Col), Catania-1 (Ct), Tsushima-0 (Tsu), Kaunas-0 (Kn), Würzburg-0 (Wu), Landsberg erecta (Ler), Burren-0 (Bur), Martuba-0 (Mt), Nossen-0 (No), Hilversum-0 (Hi), Rschew-4 (Rsc), Canary Islands-0 (Can), Oystese-0 (Oy), Wilna-2 (Wil), Poppelsdorf-0 (Po), Edinburgh-0 (Edi), Wassilewskija-0 (Ws), San Feli-2 (Sf), Zurich-0 (Zu). AT2G20910 (arrow) did not express in Col but in Ler and another three accessions. Gray indicates that the genes were not analyzable in the data-set, which was generated by the 19 Genomes Project . RPKM, reads per kilobase per million mapped reads. (c) Expression of nine Ler-specific H3K27me3 targets in Col and Ler at different developmental stages or tissues. Expression was measured by qRT-PCR, and is plotted relative to the reference gene AT1G13320. Analyzed time points and tissues are as indicated. Expression was measured in two independent experiments with similar results.