Role of plant hormones in cambial activity of Eucalyptus globulus

Abstract

The role and biosynthesis of plant hormones during cambial differentiation in eucalypts was studied using both in vivo and in vitro systems. Effects on cambial growth in culture were recorded after using gibberellins (GAs) and auxins, both alone and combined. To study gibberellin transport and metabolic pathways, labelled [ 3H] or [ 14C] of GA 1, GA 19, GA 20, and GA 44 were applied at midpoint to the cortex of 1.5-year-old E. globulus trees. Six seedling regions were separately collected, including young shoots, GA application point, cambial region and leaves above and below the application point. Radioactive signals were recorded at all six seedling regions, indicating that applied GAs wer..