Figure 6

Uptake of AsA related metabolites by Nicotiana benthamiana leaf discs. N. benthamiana source leaf discs were prepared as described in Materials and Methods and incubated with 25 mM MES pH 5.5, 20 mM CaCl₂ and the appropriate labelled substrate (at a final S.A. of 18.5 kBq mmol^-1) for 3 h in the light (200 μmol m^-2 s^-1). Leaf discs were washed, dried and lyophilised prior to exposure to Kodak Biomax X-ray film for 1 week. With all substrates tested, labelling is observed in both the major and minor (arrows) leaf veins. Labelling intensity appeared much higher with sucrose and mannose compared with the other substrates.