A Cytochemical Study of Nucleic Acids in Plant Cells

V. Nucleic acids of Feulgen negative plants

Abstract

1. Some findings an the nucleic acids of Feulgen negative plants, Oscillatoria limosa, Spirogyra sp. and Marchantia polymorpha, studied by the Feulgen's staining method and biochemical procedures, are reported.
2. Cells of these plants were not stained with Feulgen's method under various conditions of fixations and acid hydrolysis, but certain amounts of DNA were isolated biochemically from cells of these plants. Isolated DNA gives positive reaction with Feulgen's and Dische's tests in vitro. Absorption maximum of the Feulgen's color at pH 2.28 with DNA from these plants, locates at 565mμ.
3. Maximum of UV-absorption curve of DNA, isolated by Schmidt and Thannhauser's method from above plants, situates at 260mμ in all cases, and no significant difference among UV-absorption curves of DNA from these plants and calf thymus, has been found. UV-absorption maximum of DNA, isolated by the procedure of Ogur and Rosen using hot PCA, however, locates at 268mμ. Similar results are obtained when calf thumus and fish sperm-DNAs have been heated with hot PCA.
4. Nucleic acids and other P-containing substances in cells of these Feulgen negative plants are determined quantitatively. Especially, DNA and RNA have been determined by several methods for the estimation of three major constituents of nucleic acids. Mean values of DNA content per cell in Oscillatoria limosa, Spirogyra sp. and Marchantia polymorpha are 8.1, 2.9 and 0.48×10^-9mg respectively.
Causal analyses of Feulgen negativity in histochemical preparations will be discussed in another paper.