Comparison of Protein Variations in Thlaspi Caerulescens Populations from Metalliferous and Non-Metalliferous Soils

Abstract

In this work we analysed the protein variations which occurred in two Thlaspi caerulescens populations when subjected to 0 and 10 μM nickel (Ni) treatments: the Ni hyperaccumulator T. caerulescens from a metalliferous soil in Italy and T. caerulescens from Czech Republic, adapted to grow on a non-metalliferous soil. Ni accumulation in roots and shoots and the effect on growth and morphology were examined. Leaves proteins profiles of Ni treated and untreated samples were analysed by two dimensional liquid chromatography technique. From the comparison of more than 500 proteins, few differences were observed between treated and untreated plants of the same population. Differences were found between the two Thlaspi populations, instead. Proteins involved in transport, metal chelation, and signal transduction increased in abundance in the 10 μM Ni treated samples while, in condition of absence of Ni, proteins involved in sulphur metabolism, protection against reactive oxygen species and stress response showed to increase in abundance in the two populations. These proteins can be used as biomarkers both for monitoring biodiversity in indigenous plants and for selection of Ni phytoremediation plants.

KEY WORDS:

• Thlaspi caerulescens
• metal hyperaccumulator
• protein variations
• liquid chromatography
• functional biomarkers

ACKNOWLEDGMENTS

The work was supported by the contribute of FIL (University of Parma Local Funding for Research) to Prof. Nelson Marmiroli and by project ENVIREN to Prof. Elena Maestri. We are grateful to Dr. Mark G.M. Aarts (Laboratory of Genetics, Wageningen University, The Netherlands) for providing the seeds of T. caerulescens population from Czech republic and to Dr. Andrea Saccani, the Director of the Monte Prinzera Natural Reserve for providing the seeds of T. caerulescens MP population. The authors acknowledge the kind assistance of the personnel of CIM (Interdipartimental Measure Centre, University of Parma) for access to MALDI-TOF-MS facilities. Thanks also to the COST Action 859 for fruitful exchanges between different EU laboratories.