Fig. 4

Expression validation of PRC2 genes and TOR and OSR2 in diploid and tetraploid plants. a qRT-PCR analysis showing increased expression levels of DME and PRC2 genes (FIS2 and MEA) in the central cells of tetraploid relative to diploid plants. b Relative expression ratio changes of the genes associated with (+) H3K27me3 (H3K27me3 target genes) or without (−) H3K27me3 (H3K27me3 non-target genes) in the central cell between tetraploid (CCt) and diploid (CCd) plants. The ratios were calculated using average expression values from eight biological replicates. The genes associated with H3K27me3 had significantly lower expression ratio changes than the genes without H3K27me3 (P < 1e⁻⁷, Wilcoxon rank-sum test). c, d qRT-PCR analysis showing increased expression levels of TOR (c) and OSR2 (d) in egg and central cells of diploid and tetraploid plants. ERCC_171 was used as an internal control, which was equally added for each cell before reverse transcription. Double asterisks indicate a statistical significance level of P < 0.01 (Student’s t test)