Fig. 4: A jasmonic acid-mediated chromatin-state switch controls petal abscission.
From: Petal abscission is promoted by jasmonic acid-induced autophagy at Arabidopsis petal bases
a Left, Venn diagram showing the overlap between direct MYC2 targets, direct MED25 targets, and 70 high-confidence JA-regulated genes. Twenty-five out of 70 high-confidence JA-regulated genes are common direct targets of MYC2 and MED25. Right, pie chart of DNase I-hypersensitivity assay for 25 high-confidence JA-regulated genes. b Heatmap representation of the absolute expression values of the 25 above genes based on public transcriptome data. c, IGV browser view of MYC2, MED25 and H3K9Ac ChIP-seq signals, MNase-seq signals and DNase I-hypersensitive sites (HSs). Binding of MYC2 (d) and MED25 (e) at shared loci based on ChIP–qPCR. Positions of PCR amplicons for ChIP–qPCR are shown in c. Values are means ± standard error (n = 4 independent experiments). Asterisks indicate statistically significant differences between the direct target and the negative control (TA3) based on one-tailed Student’s t test (MYC2 ChIP, STP13: p = 0.03; ANAC102: p = 0.03; RAV1: p = 3.9 ×10−4; SAG14: p = 0.03) (MED25 ChIP, STP13: p = 7.0 ×10−4; ANAC102: p = 1.5 ×10−3; RAV1: p = 0.03; SAG14: p = 4.8 ×10−3). Association of TPL–HA (f), HDA19–GFP (g), MED25–GFP (h), H3K9ac (i) and Pol II (j) at the ANAC102 promoter in WT and the dad1 mutant based on ChIP–qPCR. Positions of PCR amplicons for ChIP–qPCR are shown in c. Values are means ± SE (n = 3 independent experiments). Asterisks indicate statistically significant differences between WT and dad1 based on one-tailed Student’s t test (f: p = 0.03; g: p = 0.03; h: p = 4.2 ×10−4; i: p = 0.01; j: p = 7.4 ×10−3). k Chromatin accessibility at the ANAC102 promoter in the WT and the dad1 mutant based on FAIRE–qPCR. Positions of PCR amplicons for ChIP–qPCR are shown in c. Values are means ± SE (n = 3 independent experiments). Asterisks indicate statistically significant differences between the wild type and dad1 based on one-tailed Student’s t test (p = 0.01). l Protein–protein interaction between MYC2 and the repressor TPL or the activator MED25 in the nuclei from WT petals at position 3. Magenta: DNA; green: PLA signals detected as dots. Scale bar = 5 µm. m Frequency of petal cell nuclei with PLA signals. p-values were determined by one-sided Chi-squared test. p < 0.05. n Quantification of number of PLA signals, shown as violin plots. n = 33. Asterisks indicate statistically significant differences between MYC2–TPL and MYC2–MED25 interaction based on two-tailed Student’s t test.
