Globulin storage proteins have been characterized in spores of temperate fern species Matteucia struthiopteris (Templeman et. al. 1987 Plant Physiol. 85:343, Roden & Rask 1990 Eur. J. Biochem. 192:101), Onoclea sensibilis and Osmunda cinnamea (Templeman & DeMaggio 1990, Amer. J. Bot.77:284). The globulins have apparent similarity to seed storage proteins (Templeman et al. 1987; Rodin & Rask 1990). Proteins in spores of two strains of Ceratopteris richardii, a tropical fern, are being characterized and compared to the proteins in Onoclea spores. The Hn-n strain have haploid spores that have an after-ripening requirement whereas spores of the RN5 strain lack this requirement. Total protein content of both strains are 2% or less on a dry weight basis, significantly less than Onoclea spores. Proteins are extracted from dry (Hn-n & RN5), imbibed but quiescent Hn-n, and germinated RN5 spores in 20mM Tris/HCl pH 8 buffer containing 0.5M NaCl, 5mM EDTA, and 1mM PMSF. Protein patterns were compared using SDS-PAGE and native-PAGE electrophoresis. No differences in protein patterns between dry Hn-n and RN5 were found, although the pattern differed significantly from dry Onoclea spores. A protein band of about 1.4 kDa declined in both quiescent Hn-n and germinated RN5 spores. Two unique bands approximately 4.5 and 20.5 kDa appeared in the germinated RN5 spores. Preliminary results suggest that certain proteins in both Onoclea and Ceratopteris are glycoproteins. Additional experiments are underway to further characterize the proteins in Ceratopteris spores.

Key words: Ceratopteris richardii, analysis by electrophoresis, fern spores, storage proteins