Title: Transportprozesse in Vallisneria-Blättern und die Wirkung von Kinetin und Kolchizin
Abstract: 1. Leaf strips of Vallisneria spiralis L. are treated in three different zones in a different way: To zone I the radioactive amino acid (α-aminoisobutyric acid = AIB) is applied; the transport proceeds through the adjacent zone II; zone III is incubated with kinetin. Kinetin (1μM) applied in zone III induces a directed transport of AIB from zone I towards zone III. The result is a kinetininduced accumulation of AIB in zone III. Zone II also shows a higher content of AIB. Thus the question arises as to whether kinetin induces a long-distance effect or kinetin itself (or its active principle) is transported. 2. It has been shown by a refined analysis that the accumulation effect of kinetin does not spread over the whole leaf from the sink to the source but under optimal conditions is restricted to a region which extends about 2 cm in zone II. 3. The increased accumulation capacity in zone II can be maintained after cutting off zone III which was pretreated for 52 hours with kinetin. 4. The distribution of AIB in the leaf strip is not affected by kinetin as long as AIB has not reached that part of the leaf influenced by kinetin. 5. A transport of radioactivity can be observed after application of labelled kinetin, which is in accord with the spreading of the kinetin effect. 6. Further evidence for a transport of kinetin is obtained by another experiment which makes use of the Richmond-Lang effect. Kinetin retards yellowing, an effect which is concentrationdependent. Kinetin (1 μM, 10 μM, 50 μM or 0,1 mM) is applied to the middle part of a leaf strip, and the process of yellowing is observed over a period of 2 weeks: With 0,1 mM kinetin solution the cells are killed at the site of application; in both directions of the leaf strip yellow regions are followed by large green zones and the ends of the strips are yellow, too. This is a sequence of kinetin actions as expected according to decreasing concentrations of kinetin. 7. We conclude that there is no long-distance effect of kinetin. All effects of kinetin which extend beyond the side of application can be explained in terms of transport of the hormone itself or of an active derivative. We believe that kinetin can alter the source-sink relationship by creating or increasing a sink.
Publication Year: 1975
Publication Date: 1975-01-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 9
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot