Spore proteins of different species and isolates of arbuscular
mycorrhizal (AM) fungi were compared by PAGE. Reproducibility of
protein patterns was assessed by using cultures of the same species either
grown on different host plants, or produced during
successive propagation cycles and stored up to 5 years. The results
consistently showed that host species, different generations and
storage, did not affect protein profiles, thus validating the accuracy
of the method. Comparison among different geographical isolates
of the same species revealed consistent protein patterns. The
stability and diversity of spore protein profiles suggested that PAGE
could be used to discriminate and identify AM fungal species and
isolates. By contrast, the physiological state of spores affected the
quality and quantity of bands, with germinating spores showing
marked profile changes, as compared to quiescent spores, both in
denaturating and native analytical conditions. The disappearance of
some polypeptides in germinated spores might be related to the
occurrence of storage proteins in AM fungi.