title: Populus trichocarpa DNase I hypersensitivity
design: The isolated nuclei were re-suspended in digestion buffer (10 mM Tris at pH 7.4, 10 mM NaCl, 3 mM MgCl2) and digested with DNase I (Zymo Research, Irvine, CA, USA) using concentrations from 0.5 - 5.0 enzyme units for 10 minutes at 37°C. Digested DNA was extracted with chloroform-isopropanol, and gel size-selected to isolate 200 - 500 bp fragments. Library construction was performed using TruSeq DNA Sample Prep kit (Illumina, San Diego, CA, USA) according to manufacturer’s protocol and sequenced using Illumina HiSeq 2500 in 50 bp single-end sequencing mode.