Experimental setup to study the pathophysiological and molecular changes in P. armandii following artificial inoculation with four ophiostomatoid species. For the pathophysiological assay, 6-year-old saplings were treated with either ophiostomatoid fungi or 2% MEA as designated by different colored lines and healthy trees, respectively. Bark and host monoterpene were harvested at 1, 30 and 90 d.p.i. after inoculation. After 30 and 90 d.p.i., necrotic lesions were measured. Xylem was stained at 90 d.p.i. after inoculation. The red number represents the number of P. armandii inoculated (270)/sampled (90 + 5, 12). For the transcriptome assay, 4-year-old saplings were treated with 2% MEA, L. qinlingense, O. shennongense and O. shennongense + L. qinlingense, respectively, as signified by differently colored lines. mRNA-seq was conducted on mRNA extracted from bark tissue harvested from P. armandii at 30 d.p.i.