MOM1 is expressed in developing ovules and participates in SUF4 and EC1 expression. A, GUS activity driven by pMOM1::GUS is detected in the FG and in the sporophytic tissues of mature ovules. f, Funiculus; fg, FG; oi, outer integument. Bar = 20 µm. B, In mom1-3 mutants hemizygous for pEC1.1(-457)::GUS, enzymatic GUS activity is detected in 25% to 36% of the analyzed egg cells (arrows). A total of 589 ovules were analyzed. C, Quantitative RT-PCR analyses to monitor SUF4 expression in mom1-3 flowers. SUF4 expression is reduced compared with wild-type (wt) flowers. D, In mom1-3 mutant pistils, all five EC1 genes are down-regulated, as shown by quantitative RT-PCR analysis. E, ChIP using an anti-H3K9ac antibody. ChIP enrichment was evaluated by quantitative PCR analyses. EC1 genes are enriched in H3K9ac in mom1-3 inflorescence in comparison with wild-type ones. Immunoprecipitation efficiency was tested by quantifying H3K9ac marks in the IAA8 locus (Zhou et al., 2010). Cycle threshold values were used to calculate the immunoprecipitation/input signal. ChIP enrichments are presented as the percentage of bound/input signal.