These authors contributed equally to this work.
18O enrichment in phosphorus pools extracted from soybean leaves
Article first published online: 29 OCT 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 197, Issue 1, pages 186–193, January 2013
How to Cite
Pfahler, V., Dürr-Auster, T., Tamburini, F., M. Bernasconi, S. and Frossard, E. (2013), 18O enrichment in phosphorus pools extracted from soybean leaves. New Phytologist, 197: 186–193. doi: 10.1111/j.1469-8137.2012.04379.x
- Issue published online: 26 NOV 2012
- Article first published online: 29 OCT 2012
- Manuscript Accepted: 8 SEP 2012
- Manuscript Received: 17 JUL 2012
- ETH Zurich. Grant Number: ETH-02_10-2
- Delley Seeds and Plants Ltd
- acid phosphatase;
- δ18O of leaf water;
- structural P;
- TCA-soluble reactive P (TCA P)
- The objective of this study was to investigate the isotopic composition of oxygen bound to phosphate (δ18O-PO4) in different phosphorus (P) pools in plant leaves. As a model plant we used soybean (Glycine max cv Toliman) grown in the presence of ample P in hydroponic cultures.
- The leaf blades were extracted with 0.3 M trichloroacetic acid (TCA) and with 10 M nitric acid. These extractions allowed measurement of the TCA-soluble reactive P (TCA P) that is rapidly cycled within the cell and the total leaf P. The difference between total leaf P and TCA P yielded the structural P which includes organic P compounds not extractable by TCA.
- P uptake and its translocation and transformation within the soybean plants lead to an 18O enrichment of TCA P (δ18O-PO4 between 16.9 and 27.5‰) and structural P (δ18O-PO4 between 42.6 and 68.0 ‰) compared with 12.4‰ in the phosphate in the nutrient solution.
- δ18O values of phosphate extracted from soybean leaves grown under optimal conditions are greater than the δ18O-PO4 values of the provided P source. Furthermore, the δ18O-PO4 of TCA P seems to be controlled by the δ18O of leaf water and the activity of inorganic pyrophosphatase or other pyrophosphatases.