Histochemistry. X. Distributions of Aluminum, Phosphorus, and Other Elements in Bupleurum falcatum Root Cultivated in Japan

Abstract

The concentrations and distributions of nine elements and three saikosaponins in Bupleurum falcatum root cultivated in Japan were histochemically examined by means of an electron microprobe X-ray microanalyzer (EXMA), inductively coupled plasma spectrometry (ICP) and high-performance liquid chromatography. Point and line analyses by semi-quantitative EXMA coupled with quantitative ICP proved to be a convenient and selective method for histochemical analysis of the tissue-specific distributions of the elements in plant roots. The present histochemical examination showed that aluminum and manganese along with three saikosaponins a, c and d occur exclusively in the outermost peripheral layer, consisting of a cork layer and pericycle, of the root, and that phosphorus occurs in the innermost xylem layer at a high concentration.