BIOCHEMISTRY OF FERN SPORE PROTEINS: GLOBULIN STORAGE PROTEINS IN ONOCLEA SENSIBILIS AND OSMUNDA CINNAMOMEA

Onoclea sensibilis was found to contain globulin storage proteins of 2.0S and 11.3S. These globulins, comparable in size and subunit composition to the spore storage proteins characterized in Matteuccia struthiopteris (Templeman, DeMaggio, and Stetler, 1987), declined during imbibition and the initial stages of spore germination. Osmunda cinnamomea, a fern that is only distantly related to Matteuccia, also contained globulin proteins, but these had S values of 5.5 and 11.3. SDS-PAGE analysis revealed extensive differences in banding patterns of the 11.3S protein between Onoclea and Osmunda. This work indicates that while globulin proteins are important storage materials in a variety of ferns they exhibit considerable molecular heterogeneity. The observed heterogeneity in the globulin proteins may be a useful tool to explore evolutionary relationships in the ferns.