Speaker
Description
Synchrotron X-ray fluorescence (SXRF) is a powerful technique for investigating element distribution in plant tissues. However, the analysis of fresh, highly hydrated samples remains challenging, as water can attenuate fluorescence signals and dehydration during data acquisition may alter tissue structure and elemental distribution. While substantial anatomical and structural heterogeneity already complicates SXRF analyses of fresh roots, stems, and leaves, fleshy fruits pose an additional challenge due to their high water content. The combined effects of tissue hydration, structural fragility, and prolonged acquisition times hinder the development of robust sample-preparation protocols, thereby limiting the use of SXRF in horticultural fruit research. The aim of this work was to optimize sample preparation protocols for SXRF analysis of fresh tomato tissues, including roots, stems, leaves, and fruits. A range of preparation strategies was evaluated, including different mounting approaches, heat- and freeze-drying treatments, and hydration-preservation methods adapted to each tissue type. Protocol performance was assessed at the CHESS Facility at Cornell University according to sample stability during acquisition, resistance to dehydration, preservation of tissue morphology, and the quality of the resulting elemental maps. The optimized protocols enabled the acquisition of high-quality SXRF datasets from fresh tomato tissues with minimal dehydration-induced artifacts. Both heat-dried and freshly prepared fruit samples consistently revealed a Cu accumulation pattern associated with the pericarp vasculature across five tomato species, suggesting a possible link between Cu distribution, vascular lignification, and fruit firmness. High-quality elemental maps were also obtained from fresh leaves. In contrast, although the protocols developed for seedling roots and stems effectively maintained sample hydration, achieving an optimal balance between tissue preservation and spatial resolution remained challenging.
These findings provide practical guidelines for SXRF analysis of hydrated plant tissues and expand the applicability of synchrotron-based elemental imaging to fresh horticultural crops.