Rapid loss of phosphorus from dying ryegrass roots: the chemical components involved
✍ Scribed by W. R. Eason; E. I. Newman
- Publisher
- Springer-Verlag
- Year
- 1990
- Tongue
- English
- Weight
- 337 KB
- Volume
- 84
- Category
- Article
- ISSN
- 0029-8549
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✦ Synopsis
Lolium perenne was grown in solution culture with either ample or deficient phosphate supply ('high-P' and 'low-P' plants). The concentration in the roots of phosphorus as water-soluble compounds, phospholipid and insoluble residue was measured. A supplementary experiment showed that the concentration of each component in the roots of low-P plants was similar to that in plants grown in P-deficient soil. The time-course of the decline of each P component was determined in roots detached from the shoot and left hanging in solution. During the three weeks residue P concentration in the roots declined little. In contrast, both types of root lost about three-quarters of their lipid P in the first week. Low-P roots lost little of their water-soluble P. High-P roots contained much more water-soluble P and lost much of it during the first two weeks. By the end of three weeks their water-soluble P content was levelling out at a value similar to that in low-P roots, suggesting a 'non-labile pool'. The rapid loss of lipid P from low-P roots comprised more than half of their total loss, and the possible ecological significance of this is discussed.