Comparison of Acid Soluble Protein Synthesis in Roots of Endomycorrhizal Wild Type Pisum Sativum and Corresponding Isogenic Mutants

The aim of this study was to compare profiles of acid soluble proteins in roots of Pisum sativum L. cv. Frisson and non-mycorrhizal mutants (myc−) when infected by vesicular arbuscular mycorrhiza funghi. Quantitative and qualitative modifications were detected by native or SDS PAGE in the protein composition of acidic extracts of endomycorrhizal roots of myc+, nod+ wild type P. sativum and of a myc+, nod-mutant, as compared to uninoculated control plants or a myc−, nod− mutant, whether this was inoculated or not with Glomus mosseae. In native PAGE two proteins, already present in extracts of non-mycorrhizal pea roots, were enhanced in G. mosseae-infected myc+ plants (nod+ or nod−). One protein which appeared after inoculation with G. mosseae or G. fasciculatum in the roots of all pea plants, including the myc−, nod− mutants, may be associated with appressorium formation. Four new proteins were detected in root extracts of G. mosseae-infected myc− peas (nod+ or nod−), as compared to the myc−, nod− mutant or uninoculated controls. One of these was probably of fungal origin, since it was also found in G. mosseae-infected tobacco and leek roots. These plants showed protein modifications different to those in endomycorrhizal peas, suggesting host-specific responses. SDS PAGE revealed the presence of two polypeptides of about 25 and 35 kDa in endomycorrhizal roots of myc+ peas. None of the endomycorrhiza-related proteins detected in roots corresponded to those extracted from spores of different fungi. This study provides new evidence that different molecular modifications occur during successful (myc+ pea, leek, tobacco) and unsuccessful (myc− pea) endomycorrhiza infections, some of which are host-determined and others related to the expression of the fungal genome.