title: Evolutionary network genomics of wood formation in a phylogenetic survey of angiosperm forest trees
design: Woody tissues were harvested from the middle third of the plant by lightly scrapping the xylem side of a debarked stem using a double-edged razor blade. For gravi-stimulated plants, developing xylem was separately harvested from the upper surface (tension wood) and from the lower surface (opposite wood) of a leaning stem. For time zero samples, two upright grown trees were randomly divided in half and independent xylem samples wereharvested. All tissue was immediately flash frozen in liquid nitrogen and stored at -80C. Frozen tissue was ground to a fine powder in liquid nitrogen and total RNA was extracted using TRIzol reagent. RNA samples were subsequently cleaned using a Qiagen RNeasy on-column DNase treatment. RNA sequencing libraries were generated using KAPA mRNA Hyper Prep Kit and multiplexed using 12 unique adapter sequences . Multiplexed samples were sequenced using 50 bp single-end runs on an Illumina HiSeq 4000 system.