Changes in concentration of protein and nucleic acids in the endosperm during ovule development in Clivia miniata

Abstract

Changes of protein and nucleic acid concentrations in micropylar and chalazal parts of the endosperm during exponential and stationary phases of embryo growth (Clivia miniata Regel) were examined. The following facts were established: 1. evident two-phase synthesis of protein, DNA and RNA in the endosperm, 2. existence of chalaza-micropyle concentration gradients of analyzed compounds, 3. elongation of the embryo proceedes from the micropylar to the chalazal end of the ovule, i. e. in the direction oposite to that of the chalaza - micropyle protein, DNA and RNA concentration gradients, 4. decrease of concentrations of protein, DNA and RNA in the endosperm after the first maximum of these compounds. Protein concentration was determined spectrophotometricaly using the method of Lowry, RNA concentration was deter-mined with the orcin method, and concentration of DNA with the diphenylamine method.