Targeted proteomics to identify cadmium-induced protein modifications in Glomus mosseae-inoculated pea roots

Arbuscular mycorrhiza (AM) can increase plant tolerance to heavy metals. A targeted proteomic approach was used to determine the putative identity of some of the proteins induced/modulated by cadmium (Cd) and to analyse the impact of the mycorrhizal process. The effect of Cd (100 mg Cd kg(-1) substrate) applied either at planting or 15 d later on two pea (Pisum sativum ) genotypes, differing in sensitivity to Cd inoculated or not with the AM fungus Glomus mosseae, was studied at three levels: plant biomass production, development of G. mosseae and root differential protein display with one- and two-dimensional gel electrophoresis (1-DE and 2-DE) analyses. Cd-induced growth inhibition was significantly alleviated by mycorrhiza in the Cd-sensitive genotype. The AM symbiosis modulated the expression of several proteins, identified by liquid chromatography-tandem mass spectrometry, newly induced and upregulated or downregulated by Cd. The protective effect of AM symbiosis towards Cd stress was observed in the Cd-sensitive genotype. Our results demonstrate the usefulness of proteomics to better understand the possible role of AM symbiosis in detoxification/response mechanisms towards Cd in pea plants.