library_construction_protocol: nuclei were extracted from each sample, and the nuclei pellet was re-suspended in the Tn5 transposase reaction mix.The transposition reaction was incubated at 37°C for 30 min. Equimolar adapter 1 and adapter 2 were added after transposition. PCR was then performed to amplify the libraries. After the PCR amplification, libraries were purified with the AMPure beads and the quality of libraries was assessed with Qubit. The clustering of the index-coded samples was performed on a cBot Cluster Generation System using TruSeq PE Cluster Kit v3-cBot-HS (Illumina) according to the manufactuer's instructions. After cluster generation, the library preparations were sequenced on an Illumina Hiseq platform and 150 bp paired-end reads were generated.