This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (60) Citing Articles via Google Scholar Google Scholar Articles by Ohad, I. Articles by Schramm, M. Search for Related Content PubMed PubMed Citation Articles by Ohad, I. Articles by Schramm, M. Agricola Articles by Ohad, I. Articles by Schramm, M.

Articles

Biogenesis and Degradation of Starch

I. The Fate of the Amyloplast Membranes during Maturation and Storage of Potato Tubers ¹

^a Department of Biological Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel

Storage of mature or developing potato tubers (Solanum tuberosum "Up-to-Date" variety) at 4 C causes a reduction in the starch content and the elevation in the level of free sugars. This phenomenon is not observed when the tubers are stored at 25 C. Changes in the morphology of cells from developing or mature tubers after storage at 4 or 25 C have been followed by electron microscopy. During all stages of the tuber development the starch granules are surrounded by a membrane derived from the plastid envelope. Storage in the cold induces disintegration of this membrane. A membrane fraction isolated from starch granules of tubers stored at 4 C has a lower buoyant density, and the electrophoretic pattern of its proteins is different from that of a similar membrane fraction obtained from tubers stored at 25 C. It is suggested that the cold-induced changes in the starch and sugar content during storage of potato tubers might be correlated with damage to the membranes surrounding the starch granules and changes in their permeability to degradative enzymes and substrates.