Vital Staining by Fe and Mn Salts for Electron Microscopy of Plant Tissue (Elodea)

Abstract

Electron microscopy can demonstrate Fe or Mn accumulated by living Elodea leaves from a solution containing ions of either of these two metals. The Fe and Mn accumulation is deemed to be metabolic because it does not interfere with growth or cyclosis, and because it occurs in light only–not in darkness. The metals, therefore, constitute vital stains within the leaf cells, which intensify pictures of the endoplasmic reticulum, plasmalemmae, tonoplasts, and structures of the cell walls, nuclei, chloroplasts, and mitochondria. The electron micrographs show differences between Fe and Mn distribution, apparently due to the individual biochemical behavior of the two elements. This can be demonstrated at the submicroscopic level where each is utilized as a constituent of an enzyme or in the production of an Fe or Mn containing metabolite.