Wydział Biologii

Micronutrients such as Zn, Cu, Fe, Mn play essential roles in plant physiology, yet their low concentrations and tissue-specific distributions pose significant analytical challenges. While various imaging techniques exist, most either sacrifice resolution for throughput or lack the ability to quantify elemental co-localization across scales.

In this study, using POLYX beamline at National Synchrotron Radiation Centre SOLARIS we applied micro X-ray fluorescence (μXRF) mapping to investigate the spatial distribution and co-localization of Zn, Cu, Fe, Mn, and Ca in plant roots. Whole-root scans at 100 µm resolution provided an overview of elemental architecture, while selected regions imaged at 5 µm resolution revealed tissue-level heterogeneity. To interpret elemental relationships, we generated overlap matrices using both loose (92%) and strict (97%) intensity thresholds, and calculated Pearson and Spearman correlation coefficients alongside Manders’ overlap metrics. Our results show that coarse resolution inflates apparent co-localization, particularly for Zn, which appears broadly distributed at 100 µm but is confined to outer tissues at 5 µm. In contrast, Ca-based overlaps remained stable across scales, while Fe–Mn pairs showed intermediate resolution sensitivity. This study demonstrates that whole plant root may be analysed using POLYX beamline setup with multiresolution range (from 5 µm). We show a methodological framework for micronutrient localization in roots of relatively large (beyond seedling) planta and offer first insights into potential difference in elements heterogeneity that may result from the spatial regulation of nutrient uptake and transport.