Micro-PIXE studies of elemental distribution in seeds of Silene vulgaris from a zinc dump in Olkusz, southern Poland

Some plants growing on heavy metal enriched soils have evolved tolerance to such metals. Silene vulgaris (Moench.) Garcke, Caryophyllaceae is one of the common pioneer species of zinc dump flora and can be treated as a model species for the study of metal tolerance in higher plants. The NAC nuclear microprobe was used to compare elemental distribution in seeds by the simultaneous use of PIXE and proton backscattering spectrometry (BS). Quantitative elemental maps showed that seed tissues were defined by specific elemental allocation patterns. Distribution of Zn throughout the seed was relatively homogeneous, with limited accumulation in the testa, around the hilum and in the endosperm adjacent to the embryo. Exclusion of Zn from embryonic tissues may allow S. vulgaris to maintain reproductive success in an environment of high Zn availability.