DNA rbcL metabarcode of test sample
DNA and RNA were extracted from sand or soil samples using Qiagen RNeasy PowerSoil Total RNA Kit and the Qiagen RNeasy PowerSoil DNA Elution Kit and amplified with plant universal primers (either rbcL, ITS2, or matK) using one-step RT-PCR (Qiagen) or regular PCR. Nucleotide concentrations were measured with Qubit and adjusted to equal molar concentrations before combining into one library before sequencing. Sample name designates the sample type. First letter (R or D) indicates DNA or RNA sequencing. Next number (1-11) indicate the type of sample prepared. 1 = Salvia leucophylla seed in sterile sand. 2 = Salvia leucophylla seed in sterile sand treated in deionized water. 3 = Salvia leucophylla seed in sterile sand treated in gibberellic acid. 4 = Salvia leucophylla seed in sterile soil from the field. 5 = Salvia leucophylla seed in sterile soil from the field treated in deionized water. 6= Bromus diandrus root tissue in sterile soil from the field. 8 = Salvia leucophylla and Bromus diandrus root tissue in sterile soil from the field. 9 =  Salvia leucophylla and Bromus diandrus root tissue in sterile soil from the field treated in deionized water. 10 = air dried field soil. 13 = Sterilized soil. 14 = Sterilized soil treated in deionized water. Second letter (a - e) indicates replicate. Not all replicates successfully amplified. Some samples were redone with different concentrations of the RNA or DNA. Last letter indicates barcode (I = ITS2, r = rbcL, m = matK, t = trnL).