Role of genetic control and self-assembly in gametophyte sporoderm ontogeny: Hypotheses and experiment

A review of our own and literature data on the mechanisms of sporoderm (the wall of pollen grains and spores) development is presented in terms of colloidal interactions—the so-called micellar hypothesis (Gabarayeva and Hemsley, 2006; Hemsley and Gabarayeva, 2007), which suggests the participation of self-assembly processes in development. The development of exine (sporopollenin-containing part of the sporoderm) in five plant species from remote taxa has been traced in detail and interpreted as a micellar sequence. An experimental modeling of exine-like structures carried out in vitro, in which physicochemical patterns of colloidal systems (hydrophobic interactions) were the driving force, is strong evidence for the relevance of the micellar hypothesis and the promising nature of these studies. The correlation between the role of genomic control and self-assembly in the development of complex biological walls is discussed.