Pectins in walls of protoplast-derived cells imbedded in agarose and alginate beads

Abstract

Flax hypocotyl protoplasts were embedded in agarose and alginate beads. The pectin molecules of the formed colonies were observed in electron microscopy using 2F4 antibody specific of a calcium-induced supramolecular conformation of homopolygalacturonic acid. Little pectin, mostly methylesterified, was present in agarose-entrapped colonies. The regenerating cells immobilized in alginate secreted much higher amounts of methylesterified pectins in their walls. De-esterification of the pectins was clearly seen after 6 days of culture. These results illustrate the importance of the external matrix on wall differentiation.