Activity of sugar transport enzymes in leaves of two tomato genotypes grown under ambient and elevated CO₂ without <i>H. armigera</i>.

<p>(A) sucrose phosphate synthase (SPS) activity, and (B) sucrose synthase (SS) activity. Each value represents the average (±SE) of four replicates. Different lowercase letters indicate significant differences between CO₂ level within the same tomato genotype (LSD test: d.f. = 3.12; <i>P</i><0.05). Different uppercase letters indicate significant differences between WT plants and <i>spr2</i> plants within the same CO₂ level (LSD test: d.f. = 2.9; <i>P</i><0.05).