design: PCR amplification of the 16S rRNA gene with primers to the V3-V4 region was performed with the KAPA3G Plant kit (Sigma Aldrich, MO, USA). The PCR products were cleaned and normalized using the Just-a-plate kit (Charm Biotech, MO, USA). High throughput sequencing (HTS) was performed with Illumina MiSeq and 250 bp paired-end kits (Illumina, Inc., CA, USA).