Increased supply of boron to swiss chard plants did not affect the level of boron in a cell wall-bound form: A possible application to the diagnosis of nutrition of plants

Abstract

Swiss chard plants were water-cultured under various B levels ranging from 0.01 to 20 g B m^-3 culture solutions for 4 weeks. The B content of the shoot increased with the increase in the B supply. The increase, however, was entirely ascribed to acetate buffer (20 mol m^-3 pH 4.0)-soluble B, and the content of acetate buffer-insoluble, cell wall-bound B did not increase.. More than ca. 80% of the cell wall-bound B was associated with rhamnogalacturonan II under various B levels. The amount of acetate buffer-soluble B could be estimated from the B levels in the expressed leaf sap.