Histochemical studies on the oil-bodies ofMarchantia paleacea bert

Summary Correlated light and electron microscope histochemistry was performed on the oil bodies (OB) ofMarchantia paleacea. It was revealed that they contain significant quantities of material positive to PAS and periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) reactions. Ag deposits were localized on the matrix surrounding the globules and on the distinct one close to the inner face of the OB membrane. In addition, the lipophilic globules were peripherally impregnated with staining product. Polysaccharidic material appears to be elaborated in dictyosomes and then advanced into the OB by their vesicles.The OB show a lipophilic character and are intensely stained with Sudan black B, with an aqueous solution of osmium tetroxide and with the Nadi reaction as modified byDavid andCarde (1964).The performance of mercury bromophenol blue, aniline blue black, coomassie brilliant blue R and acid fuchsin stainings showed that the OB do not contain structurally detectable proteins. Besides, a positive reaction of the inner OB was obtained in fresh tissue with a variety of tests sensitive to phenolic or other aromatic ring compounds. On the contrary, the epidermal and scale OB containing small globules are obviously stained only with Gibbs' reagent. The colours obtained with the above reactions, were almost the same,i.e. brown with a red shade, except for the blue one of the Gibbs' reagent.The presented observations favour the conclusion that the OB matrix does not contain proteins, but substances polysaccharidic in nature. Phenolic and possibly other aromatic compounds appear to be present at least in inner OB.