title: Evidence for gibberellin-like substances in phloem exudate of higher plants.
abstract: Samples of sieve-tube sap were obtained as honeydew from aphids feeding on three species of higher plants. The honeydew was extracted, chromatographed and tested in several bioassays for the presence of gibberellin-like substances. The bioassay results indicated that gibberellin-like substances were translocated in the phloem of dandelion (Taraxacum officinale), broad bean (Vicia faba) and willow (Salix viminalis). Results obtained with willow showed that the concentration of gibberellin-like substances in the sieve-tube sap is daylength dependent, high levels being present in plants maintained under long days and low levels in short day plants.
authors: Botany Department, University College of Wales, Aberystwyth.
authors: G V
authors: GV
authors: Hoad
authors: M R
authors: MR
authors: Bowen