Untersuchungen über den Einfluß des Kinetins und des Eisens auf den Nukleinsäure‐ und Proteinstoffwechsel von Karottengewebekulturen

Abstract

The Influence of Kinetin and Iron on Nucleic Acid and Protein Metabolism of Carrot Tissue CulturesCarrot‐root tissues cultured in a nutrient solution containing Kinetin had a high rate of cell division, that led to an undifferentiated callus, and a relatively low DNA content per cell. The same tissues growing without Kinetin had a smaller rate of cell division and a higher DNA content, and showed the ability to form roots.By addition of 32P to the nutrient solution, the cultures growing with Kinetin showed a higher specific activity of DNA than those growing without Kinetin.From previous experiments and results of other workers the possibility of the occurence of a metabolic labile DNA fraction in the cultures which grew without Kinetin is discussed.A comparison between the influence of iron and Kinetin on cell division activity, root formation, DNA, RNA and amino acid content of the tissue cultures was made on a cell basis. Iron deficiency or absence of Kinetin in the nutrient solution reduced the cell division activity of carrot tissue cultures and increased the content of DNA, RNA and soluble amino acids. The protein content was reduced by iron deficiency but was increased by the absence of Kinetin.Cultures, growing without Kinetin were able to form roots, while those, growing in an iron deficient medium were unable to show the latter phenomenon.