ABSTRACT

The knowledge that has accumulated to date on the morphogenesis of protoplasts has provided a basis for further investigation into the genetic and epigenetic control of morphogenetic processes both at the cellular and the protoplast level. The morphogenesis of hybrid protoplasts during growth and reversion does not differ appreciably from the morphogenesis of the relevant parental protoplasts, although this has only been studied so far in intraspecific fusion experiments. The cell wall is a hierarchical process consisting of a set of sequential steps. As a working hypothesis one may consider the following pattern. First, various precursors are synthesized; these include glucans, mannoproteins, and chitin. Second, the precursors are transported to appropriate sites; this includes translocation through the plasma membrane. Protoplasts retain the ability to synthesize and secrete mannans and cell wall proteins as well as the glycoprotein enzymes normally destined for the periplasmic space.