Speaker
Description
Bryophytes are highly efficient sorbents of nutrients and metals, making them powerful biomonitors and model systems for studying plant metal uptake. We investigate metal distribution and ultrastructural responses in two mosses, Physcomitrium patens and Pohlia drummondii. The latter is known for its heavy metal tolerance, potentially attributable to its thick cell walls. Specimens were grown under controlled metal exposures in the laboratory.
Using nano-Synchrotron X-ray Fluorescence (nano-SRXRF) combined with simultaneous Small-Angle X-ray Scattering (SAXS) at the NanoMAX beamline at MAX IV, we mapped subcellular distributions of “housekeeping” elements (Cl, Ca, K) and contaminant metals (Fe and Cu) to assess their effects on cellular ultrastructure. We employ the Compton signal for normalization and quantification, enabling conversion from areal to volume concentrations. This allows direct comparison with the metal exposure from the agar and across scans.
At NanoMAX, the nano-focused beam and high brilliance reveal nanoscale elemental heterogeneity, which was not seen with lower resolution. We resolve previously unreported iron nanoclusters within bryophyte tissues. SAXS probes potential metal induced modifications of the cell wall, allowing us to test whether exposure produces detectable changes in scattering signatures associated with wall alterations