Fig. 3.

Effect of low and high PAR treatments on type VI leaf trichome-associated defenses in wild-type (wt) and odorless-2 (od-2) plants. Type VI trichome density was evaluated on (a) adaxial and (b) abaxial leaf sides of leaflets taken from the third/fourth youngest leaf at 35 d after initial light treatments. Values represent the mean (� SEM) of 28–29 plants from three independent experiments. (c) Main phenolic compounds identified in leaf exudates of low or high PAR-treated wild-type and od-2 plants. Values represent the mean (� SEM) of nine plants from two independent experiments. (d) Total terpene content (mean � SEM, n = 4–5) measured in leaf exudates of leaflets taken from the third/fourth youngest leaf and (e) levels (mean � SEM, n = 4–5) of individual terpene compounds. Asterisks denote significant differences between low and high PAR-treated wild-type plants analyzed by t-test or Mann–Whitney U tests (P ≤ 0.05). Different letters above bars denote significant differences among groups (ANOVA followed by Fisher’s LSD test, P ≤ 0.05). n.s. = not significant. n.d. = not detected.