library_construction_protocol: The nuclei of 12-day-old Arabidopsis wild type and four mutants were extracted in a nuclear extraction buffer (0.25 M sucrose, 10 mM Tris-HCl pH 8.0, 10 mM MgCl2, 0.3% [v/v] Triton X-100, and 0.1% cocktail, Roche) and resuspended in a nuclear purification buffer (20 mM MOPS pH 7.0, 90 mM KCl, 40 mM NaCl, 2 mM EDTA pH 8.0, 0.5 mM EGTA pH 8.0, 0.5 mM spermidine, 0.2 mM spermine, and 0.1% cocktail, Roche). The quality of the nuclei was determined under a microscope, followed by Tn5 fragmentation and DNA fragment purification. Libraries were built for ATAC-seq (Illumina Novaseq 6000; 150-bp pair-end sequencing)