VARIATIONS OF CELL-WALL PEROXIDASES IN EPICOTYLS OF CICER-ARIETINUM DURING GROWTH

Fractionation and partial purification of the proteins extracted from cell walls of Cicer arietinum epicotyl reveal the presence of two fractions with peroxidase activity, denominated Px-1 and Px-2 according to their order of elution from a SP-Sephadex chromatography column. The specific activity of the Px-2 fraction increases with the age of the epicotyls, with an inverse relationship to their growth capacity. No such a relationship could be found with the peroxidase activity of the Px-1 fractions. These results indicate that the cell wall peroxidase fraction Px-2 could be related to cell wall stiffening processes. According to this, acid pHs-values, which induce cell wall loosening processes, diminish the enzymatic activity of the Px-2 fraction to a considerable extent.