Variability in protein profiles among species, isolates and physiological stages of arbuscular mycorrhizal fungal spores

AVIO, LUCIANO¹ & MANUELA GIOVANNETTI².

¹Centro di Studio per la Microbiologia del Suolo, C.N.R., ²Department of Chemistry & Agricultural Biotechnology, Via del Borghetto 80, 56124 Pisa, ITALY.

A comprehensive characterization of arbuscular mycorrhizal fungi should involve a multidisciplinary approach, including molecular and biochemical techniques. In this work we used one-dimensional sodium-dodecyl-sulphate polyacrylamide gel electrophoresis (1-D SDS PAGE) of soluble polypeptides to compare spore protein patterns of different species and isolates of AM fungi. Consistency of protein profiles was assessed by using spores of the same species either grown on different host plants, or produced in successive propagation cycles and stored for different periods. Protein banding patterns of Glomus mosseae and G. caledonium were identical irrespective of the different host plants. Protein profiles of G. coronatum spores were identical irrespective of the different pot-culture generations and of storage length, up to 5 years. By contrast, the physiological state of spores affected the quality and quantity of bands.
Our results show the reliability of spore protein profiles as regard their reproducibility, under different environmental conditions of spore production, validating this technique and confirming the possibility of using electrophoretic protein patterns as genetic markers of an organism or a group of organisms.