16S sequencing of soil bacteria
DNA was extracted following MoBios instructions on a KingFisher robot. Bacterial 16S rRNA genes were PCR-amplified with dual-barcoded primers targeting the V4 region (515F 5-GTGCCAGCMGCCGCGGTAA-3, and 806R 5-GGACTACHVGGGTWTCTAAT-3), as per the protocol of Kozich et al. (2013).