Localization of phenols and polyphenol oxidase in 'Jewel' sweet potatoes (Ipomoea batatas 'Jewel')

Abstract

Histochemical tests for phenols and polyphenol oxidase were performed on fresh root tissue of Ipomoea batatas (L.) Lam. 'Jewel.' The phenolic compounds were localized in the phellem, phellogen, and phelloderm, in approximately 1 mm (ca. 10–15 cells) of the tissue directly beneath the periderm, in the latex of laticifers, in the phloem, in the cambium which separates the secondary phloem from the secondary xylem, in the anomalous secondary cambia of the central core, in the parenchyma cells adjacent to the xylem elements, and in the walls of the xylem elements. Polyphenol oxidase was localized primarily in the phellogen and phelloderm and most prominently in the latex of laticifers.