Fig. 4: JUMONJI demethylases are required for the removal of H3K27me3 histone modifications from heat-memory genes before acclimation.

a Schematic representation of heat-stress memory conditions. Colored dots indicate the times of different assays: phenotyping, green; RNA-seq, blue; qRT-PCR, gray; and ChIP-qPCR, red. Orange and magenta lines show the two different time-courses of β-estradiol application. b pER8::JMJ30 transgenic plants in the jmjq mutant background subjected to β-estradiol application before acclimation (1, left) and before heat shock (2, right). Plants were grown under the heat-stress memory condition. c Quantification of chlorophyll contents of plants shown in Fig. 4b. Sample minimum (lower bar); lower quartile (box); median (middle line); upper quartile (box); and sample maximum (upper bar). One-way ANOVA test; *p < 0.05. Different letters above bars indicate significant differences based on a post-hoc Tukey HSD test (p < 0.05). n = 12. d Expression heatmap of the HSP genes downregulated in jmjq, determined by RNA-seq. White asterisks indicate significant differences between WT and jmjq grown under the same conditions or between pER8::JMJ30 transgenic plants in the jmjq mutant background subjected to β-estradiol application before acclimation or before heat shock. The FDR was <0.05. e, f Gene expression levels (e) and H3K27me3 levels (f) of HSP22 and HSP17.6C in ER8::JMJ30 transgenic plants in the jmjq mutant background subjected to β-estradiol application before acclimation (①) or before heat shock (②). A two-tailed Student’s t test between pER8::JMJ30 transgenic plants in the jmjq mutant background subjected to β-estradiol application before acclimation and before heat shock; *p < 0.05.