Plant-microbe-soil interactions and their role in phytotechnologies applied to trace metal-rich soils

Abstract

This thesis aims to compare phytoextraction and phytostabilisation capacity of different plant species and to study the changes that they or their associated microorganisms produce in the bioavailability of metals in the rhizosphere. The soil-plant-bacteria system of the two subspecies of the Ni-hyperaccumulator Alyssum serpyllifolium, endemic to the Iberian Peninsula were studied with the aim to characterise its associated bacterial community. Rhizospheric processes involved in Ni solubilisation were also studied and experiments for the improvement of phytomining efficiency using soil organic amendment were carried out. On the other hand, greenhouse and field experiments were carried out on Zn, Cd and Pb or Cu-contaminated soils; the objective being the evaluation of phytoremeditiation potential of metal-(hyper)accumulators or metal-excluding plant species growing in metal contaminated soils. Moreover, in the same soils studies were carried out to improve phytoremediation efficiency through the use of soil fertilisation, organic amendments or bacterial inoculation.