Fig. 6

Level of transcripts encoding enzymes involved in secondary metabolism in E. globulus treated with OC kappa. Relative level of transcripts encoding phenylalanine ammonia-lyase (pal1, a) and terpene synthase (ts1, b), in control and in E. globulus trees treated with OC kappa at 1 mg mL^− 1 (black circles). Asterisks (*) represent significant differences (p < 0.05) between the level of transcripts at a certain week compared with the expression at the beginning of the experiments (week 0). The level of transcripts is expressed as 2^-ΔΔCt. Circles represent mean values of three independent experiments ±SD