Miseq of root metagenome
DNA extraction was performed with the FastDNA Spin kit for soil (MP Biomedicals) and were normalized to 0.3 ng.L-1 before PCR amplification. Primers AMADf (5 GGGAGGTAGTGACAATAAATAAC 3) and AMADGr (5 CCCAACTATCCCTATTAATCAT  3) were used to amplify the18S rRNA gene.  Libraries sequencing was performed on a Miseq by Fasteris SA (Switzerland).