title: Shotgun metagenomic sequencing of rhizosphere microbial community NP3
design: Sequencing libraries were generated using NEBNext Ultra DNA Library Prep Kit for Illumina (NEB, USA) following manufacturer s recommendations and index codes were added to attribute sequences to each sample. Briefly, the DNA sample was fragmented by sonication to a size of approximately 300bp, then DNA fragments were end-polished, A-tailed, and ligated with the full-length adaptor for Illumina sequencing with further PCR amplification. Finally, PCR products were purified (AMPure XP system) and libraries were analysed for size distribution by Agilent2100 Bioanalyzer and quantified using real-time PCR.The clustering of the index-coded samples was performed on a cBot Cluster Generation System according to the manufacturer s instructions. After cluster generation, the library preparations were sequenced on an Illumina HiSeq X Ten platform and 150bp paired-end reads were generated.