Major research-related accomplishments and their possible applications
1. I have demonstrated that grasses such as S. cereale and F. ovina can be used as phytostabilisers of soil-contaminating cadmium because they accumulate this metal in their roots and are characterized by the low Cd translocation to shoots.
2. I have shown that the intracellular accumulation and chelation of cadmium are the essential processes in Cd stabilization by the roots of S. cereale and F. ovina.
3. I have established than cadmium stress stimulates the rhizodeposition of organic compounds (a potential source of easily degradable carbon and nitrogen compounds), resulting in the stimulation of the proliferation of the group of microorganisms resistant to the metal and colonising the root surface of S. cereale and F. ovina forming a protective barrier.
4. I have demonstrated that Cd immobilized by the root is easily released as a result of abiotic processes (e.g. desorption under aseptic conditions) and biotic processes
(e.g. microbiological degradation of dead cells), and the final concentration of the metal in the soil solution depends on the rate of its mobilization and resorption by the mineral and organic constituents of the soil’s solid phase.
5. I have demonstrated evidence that plants, in a close interaction with their own microbiota, control the chemical composition and pH of the soil solution, determining the trend and rate of Cd migration between the plant, the soil solution and soil’s solid phase, and that the shift of the balance of processes towards metal immobilization from the liquid phase of the soil by plants (bioaccumulation) or bioprecipitation and biosorption from the rhizosphere will increase the efficiency of cadmium phytostabilization.
6. I have documented the formation of stable humus and Cd immobilization as a result of the humification of plant residues during F. ovina cultivation (a pot experiment).
7. I have proven that in the case of F. ovina grass, the loss of stability in cadmium immobilised in its roots was balanced out with the incorporation of Cd in the humus structure. This fact should be considered an important element in phytoremediation, because an increase in the humus content in soil is stimulated by plants and microorganisms.