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Phosphorus compartmentation in Pinus serotina Michx. (pond pine); observations from in vivo nuclear magnetic resonance spectroscopy
Author(s) -
Ayling S. M.,
Topa M. A.
Publication year - 1998
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1046/j.1365-3040.1998.00318.x
Subject(s) - vacuole , cytoplasm , pi , botany , phosphorus , pinus <genus> , volume (thermodynamics) , biology , chemistry , biochemistry , physics , organic chemistry , quantum mechanics
31 P nuclear magnetic resonance (NMR) spectroscopy was used to estimate the amount of inorganic phosphate (Pi) present in the cytoplasm and vacuole of root tips and subapical root segments of pond pine ( Pinus serotina Michx.). In root tips of seedlings grown with 100 mmol m –3 P (HP) the cytoplasmic Pi content, on a root volume basis, was ≈ 1·5 μ mol cm –3 and the vacuolar Pi content, on a root volume basis, was ≈ 3·4 μ mol cm –3 . In root tips from Pi starved seedlings the cytoplasmic Pi content, on a root volume basis, was ≈ 0·75 μ mol cm –3 ; vacuolar Pi was too low to be reliably estimated. Similar results were obtained with subapical root segments; the Pi concentration in the cytoplasm was maintained at around 2 mol m –3 while that in the vacuole varied with Pi supply. This work demonstrates for the first time that quantitative measurements of the subcellular compartmentation of Pi can be made in young tissues of a woody species. The results indicate that cytoplasmic Pi levels are maintained across a range of external Pi supplies probably by withdrawing Pi stored in the vacuole.