Fig. 1

Study design and sampling procedure. Needles were sampled from one tree with enhanced resistance and three susceptible adult Norway spruce trees growing next to each other in an area with naturally high C. rhododendri infection intensities (Praxmar in Tyrol, Austria). On each sampling date and for each tree, three current-year shoots from different parts of the crown were cut, the needles of each divided into four cryo vials (for RNA-Seq, phenolics, terpenes, and backup, respectively) and immediately stored at -80° C. Note that on day 38 infection symptoms were clearly visible and needles were separated into symptomatic (S) and non-symptomatic (NS) ones