Die Aufnahme von cAMP und seine Wirkungen auf den Kohlenhydrat- und Lipidstoffwechsel grüner Blätter

Abstract

When cAMP is fed to green plant tissues it is capable of entering cells and is degraded as rapidly in isolated protoplasts as in intact tissues. Effcets of cAMP on carbohydrate storage are found when concentrations exceeding 8·10 -3 M are used; the rate of CO2-fixation is influenced by >2·10 -4 M cAMP. No effects on lipid fatty acid composition und metabolism could be established, but, after application of > 4·10 -4M cAMP, the incorporation of [14C]-acetate into lipids is raised approximately by 88 %. Also, cAMP lowers the formation of leaf-necroses caused by the detergent Tween 20. All effects caused by cAMP could also be obtained by feeding 5'-AMP, therefore these effects are non-specific and there is no indication of a hormone-mimiced efficacy of the cyclic nucleotide. In most cases a distinct effect needs a cAMP concentration higher than 10 -4M and with regard to the rapid uptake, it seems probable that it is due to an influence on the adenylate pool of the cell. However, some rather specfic cAMP effects described in the literature cannot be interpreted in such a manner.