title: The subcellular concentration of ions and elements in thin cryosections of onion root meristem cells. An electron-probe EDS study.
abstract: Quantitative electron-probe energy dispersive X-ray microanalysis has, for the first time, been accomplished at a subcellular level in plant tissue using cryofixed and thin freeze-dried cryosections. The subcellular concentrations of Na+, Cl-, K+, P, S, Mg2+ and Ca2+ were measured in mol/kg dry weight in two types of root meristematic cells of the onion, Allium cepa. The cell wall of the meristematic cells had much higher concentrations of K+ and Ca2+ than was found in the intracellular compartments. Storage granules in the protoderm cells were about 6-12 times lower in P and were about four times higher in S as compared to other intracellular compartments. Comparison between the concentrations of ions and other elements in meristematic plant cells and in mouse cardiac myocytes confirms that major differences in cytoplasmic Na+ and Cl- concentrations do indeed exist between these cell types.
mesh_terms: D000818:Animals; D002473:Cell Wall / Q000032:analysis; D004577:Electron Probe Microanalysis; D004602:Elements / Q000032:analysis*; D005260:Female; D005629:Frozen Sections; D007477:Ions / Q000032:analysis*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D009206:Myocardium / Q000032:analysis; D010945:Plants, Edible / Q000032:analysis* / Q000648:ultrastructure
chemical_list: D004602:Elements; D007477:Ions