16S-seq of saline soilTomato rhizosphere
Total genomic DNAs were extracted by using the PowerSoil DNA Isolation Kit according to the manufacturers instructions (MoBio, Carlsbad, USA). Nine different spike-in sequences with at least four different concentrations (copies of internal standards) were added to the sample DNA pools. Spike-in sequences consisted of conserved regions identical to those of selected natural 16S rRNA genes and artificial variable regions as mention above. Then bacterial amplicon libraries were produced as described in (Cai et al. 2017) by amplifying the V4V5 region of the bacterial 16S rRNA gene.