Figure 2.

Changes in the adaxial (a), abaxial (b), and total (adaxial plus abaxial) (c) g_s for mature pea leaves during 9 d of UV-B treatment after leaves were turned over (indicated by the dotted line). The plants were grown from seed for 21 d prior to these measurements either without UV-B radiation (○) or with 0.30 (▵) or 0.63 W m⁻² (□) of UV-B radiation. Another treatment of 0.21 W m⁻² of UV-B radiation had no detectable effect, and is not shown. Data are the means of six replicates ± 1 pooled se derived from ANOVA shown on the last day.