Uptake and metabolism of 2-[(14)C]abscisic acid in lettuce fruits var. Great Lakes.

There are two phases of 2-[(14)C]ABA uptake in lettuce fruits. Although the first phase appears to relate to the imbibition of water, uptake continues for three hours following complete imbibition. The second phase corresponds with the commencement of radicle extension.Exogenously applied radioactive ABA is metabolised to form an unidentified substance which has chromatographic properties different to previously described ABA metabolites. When ABA is present in the bathing solution, the quantity of metabolite never significantly exceeds that of labelled ABA in the tissues.