3-EPIGIBBERELLIN A(1) - NATURAL OCCURRENCE IN PLANTS AND ARTIFACTUAL FORMATION FROM GIBBERELLIN A(1)

Whether 3-epigibberellin(3-epiGA(1)) is endogenous in plants or is for med from GA(1) as an artefact, can be determined by adding [C-13]GA(1) to the plant material as an internal reference and measuring the C-12 : C-13 ratio of 3-epiGA(1) and GA(1), recovered from the plant extract . We use this method to show that 3-epiGA(1) is not a natural constitu ent of vegetative tissues of Zea mays (maize) but is endogenous in Lac tuca sativa (lettuce).