Production and Secretion of Sucrose by Sugar-cane Leaf Tissue

Leaf discs, cut from mature plants of Saccharum officinarumwere found to accumulate large quantities of starch and sugar,amounting to some 25 per cent of their initial dry weight, during3 days of constant illumination. Secretion into the externalmedium of about one-third of the accumulated sucrose was effectedby 10^–4 M sodium iodoacetate. Concomitantly the inhibitorincreased apparent photosynthesis. Various factors, includingother respiratory inhibitors, failed to induce sucrose secretion,indicating a selective action of iodoacetate on the cell membranes.