metagenomic data from lichen thallus
For newly collected specimens, total genomic DNA was extracted from lichen thalli using the E.Z.N.A. Plant DNA DS Mini Kit (Omega Bio-Tek, Inc., USA) and following the manufacturers protocol. We prepared total genomic DNA following the standard Illumina whole genome sequencing (WGS) library preparation process with Adaptive Focused Acoustics for shearing (Covaris), followed by an AMPure cleanup process. The DNA was then processed with the NEBNext Ultra II End Repair/dA-Tailing Module end-repair, together with the NEBNext Ultra II Ligation Module (New England Biolabs), while using standard Illumina index primers. Libraries were pooled and sequenced using the HiSeq 2500 sequencer in high output mode, with 125 cycle paired-end (PE) reads at the DNA Sequencing Center at Brigham Young University, Provo, Utah, USA.