Effect of Photoperiod on Metabolism of [3H] Gibberellins A1, 3-epi-A1, and A20 in Agrostemma githago L.

Publisher Website
Google Scholar
Abstract
To determine whether daylength influences the rate of metabolism, of GA in the long-day (LD) rosette plant A. githago L., [3H]GA20 and [3H]GA1 were applied under short day (SD) and LD conditions. Both were metabolized faster under LD than under SD. [1H]GA20 was metabolized to a compound chromatographically identical to 3-erpi-GA1. [3H]GA1 was metabilized to 2 acidic compounds, the major metabolite having chromatographic properties similar to, but not identical with GA8. [3H]3-epi-GA1 applied to plants under LD was metabolized much more slowly than was [3H]GA1 and formed a very polar metabolite which did not partition into ethyl acetate at pH 2.5. Very polar metabolites were formed after the feeds of [3H]GA20 and [3H]GA1. It was not possible to characterize these very polar compounds further because of their apparent instability. Evidently, in Agrostemma GA20 is the precursor of 3-epi-GA1, but there is at present no evidence indicating the precursor of GA1.