Tissue accumulation patterns and concentrations of potassium, phosphorus, and carboxyfluorescein translocated from pine seed to the root.
Potassium (K), phosphorous (P), and carboxyfluorescein (CF) accumulate in functionally distinct tissues within the pine seedling root cortex. Seedlings of Pinus pinea translocate exogenous CF and endogenous K and P from the female gametophyte/cotyledons to the growing radicle. Following unloading in the root tip, these materials accumulate in characteristic spatial patterns. Transverse sections of root tips show high levels of P in a circular ring of several layers of inner cortical cells. K and CF are minimal in the high P tissue. In contrast, high levels of K and CF accumulate in outer cortical cells, and in the vascular cylinder. These patterns are a property of living tissue because they change after freeze-thaw treatment, which kills the cells and results in uniform distribution of K and P. K concentration can be reduced to undetectable levels by incubation of roots in 100 mM NaCl. Inductively coupled plasma optical emission spectrometry (ICP-OES) analysis and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) of root segments both reliably determine K and P concentrations.
['Pesacreta|Thomas C|TC|http://orcid.org/0000-0002-3321-8300', 'Hasenstein|Karl H|KH|']
D001692:Biological Transport D005452:Fluoresceins D008855:Microscopy, Electron, Scanning D010758:Phosphorus D028223:Pinus D018517:Plant Roots D011188:Potassium D012639:Seeds D013052:Spectrometry, X-Ray Emission D014018:Tissue Distribution
Roots Pinus pinea ICP-OES Ion distribution Mineral distribution SEM/EDS