GIBBERELLIN TRANSLOCATION IN PISUM-SATIVUM L .3. BIOLOGICAL AND BIOCHEMICAL CONSEQUENCES OF THE LE MUTATION

The physiological and biochemical consequences of treating Le (tall) a nd le (dwarf) pea seedlings with varying quantities of the gibberellin s [H-3]GA20 and GA1 have been investigated. Although the percentage up take of these compounds from the site of application on the 3-degrees stipules was low and most of the applied GA remained unmetabolised in situ, the quantitative relationship between GA translocation and GA do sage was found to be linear for GA1 but saturating for GA20. The movem ent of the GAs and their subsequently produced metabolites was mainly acropetal. They accumulated in greatest quantity in the apical extremi ties of the shoot. Overall, the extent to which GA20 was metabolished in le seedlings was considerably less than in Le pea seedlings. Althou gh all le tissues contained significantly less [H-3]GA1 than their Le counterparts, phenotypic effects of the le mutation were apparent only on internode and tendril development. Increased tissue growth, conseq uent upon GA treatment, was also apparent only in the internodes and t endrils of le plants. For internodes, GA1 content determined the mid-l ogarithmic-phase growth rate and, consequently, final length. For tend rils, GA20 rather than GA1 may be the primary stimulatory agent.