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 HighWire Citing Articles via CrossRef Citing Articles via Web of Science (51) Citing Articles via Google Scholar Google Scholar Articles by Fondy, B. R. Articles by Geiger, D. R. Search for Related Content PubMed PubMed Citation Articles by Fondy, B. R. Articles by Geiger, D. R. Agricola Articles by Fondy, B. R. Articles by Geiger, D. R.

Articles

Effect of Rapid Changes in Sink-Source Ratio on Export and Distribution of Products of Photosynthesis in Leaves of Beta vulgaris L. and Phaseolus vulgaris L. ¹

Department of Biology, University of Dayton, Dayton, Ohio 45469

Effects of increasing sink-source ratio on rate of translocation and net carbon exchange were studied by darkening all but one source leaf of Beta vulgaris L. or one primary leaf of Phaseolus vulgaris L. Rates of export of labeled material and patterns of its distribution among sinks were studied by means of GM detectors. Changes in export and import rates were compared with adjustments in starch, sucrose, and glucose levels in sugar beet source leaves before and during treatment.

Sugar beet source leaf treatments which increased sink-source ratio had no sustained effect on rates of net carbon exchange, export, accumulation of starch, or the levels of sucrose and glucose on the day of treatment. However, the rate of import into a developing sugar beet leaf increased. Similar treatment of primary leaves of bean either had no effect on the rate of export of labeled material or caused up to a 20% increase. The increase in export was sufficient to account for the increase in import of labeled material into the far-sink leaflet. Nevertheless, distribution of labeled material exported to the sink regions changed; import of labeled material into the near-sink leaflet remained nearly unchanged and that into the roots decreased.

The data indicate that rapid changes in sink-source ratio cause a redistribution of the products of photosynthesis but need not involve a change in the rate of export.

¹ This work was supported by National Science Foundation Grant PCM77-15875 (to D. R. G.).

This article has been cited by other articles:

				K. HIKOSAKA, T. TAKASHIMA, D. KABEYA, T. HIROSE, and N. KAMATA Biomass Allocation and Leaf Chemical Defence in Defoliated Seedlings of Quercus serrata with Respect to Carbon-Nitrogen Balance Ann. Bot., May 1, 2005; 95(6): 1025 - 1032. [Abstract] [Full Text] [PDF]

				R. M. Gifford, J. H. Thorne, W. D. Hitz, and R. T. Giaquinta Crop Productivity and Photoassimilate Partitioning Science, August 24, 1984; 225(4664): 801 - 808. [Abstract] [PDF]