Recent advances in the analysis of metal hyperaccumulation and hypertolerance in plants using proteomics

Hyperaccumulator/hypertolerant plant species have evolved strategies allowing themto grow in metal-contaminated soils, where they accumulate high concentrations ofheavy metals in their shoots without signs of toxicity. The mechanisms that allowenhanced metal uptake, root-to-shoot translocation and detoxification in these speciesare not fully understood. Complementary approaches such as transcriptomic-based DNAmicroarrays and proteomics have recently been used to gain insight into the molecularpathways evolved by metal hyperaccumulator/hypertolerant species. Proteomics hasthe advantage of focusing on the translated portion of the genome and it allowsto analyze complex networks of proteins. This review discusses the recent analysisof metal hyperaccumulator/hypertolerant plant species using proteomics. Changesin photosynthetic proteins, sulfur, and glutathione metabolism, transport, biotic andxenobiotic defenses as well as the differential regulation of proteins involved in signalingand secondary metabolism are discussed in relation to metal hyperaccumulation. Wealso consider the potential contribution of several proteins to the hyperaccumulationphenotype.