X-ray fluorescence spectroscopy (XRF) is an analytical tool used to determine the elemental composition in a myriad of sample matrices. Due to the XRF non-destructive feature, this technique may allow time-resolved plant tissue analyses under in vivo conditions, and additionally, the combination with other non-destructive techniques. In this study, we employed handheld and benchtop XRF to evaluate the elemental distribution changes in living plant tissues exposed to X-rays, as well as real-time uptake kinetics of Zn_(aq) and Mn_(aq) in soybean (Glycine max (L.) Merrill) stem and leaves, for 48 hours, combined with transpiration rate assessment on leaves by an infrared gas analyzer (IRGA). We found higher Zn content than Mn in stems. The latter micronutrient, in turn, presented higher concentration in leaf veins. Besides, both micronutrients were more concentrated in the first trifolium (i.e., youngest leaf) of soybean plants. Moreover, the transpiration rate was more influenced by circadian cycles than Zn and Mn uptake. Thus, XRF represents a convenient tool for in vivo nutritional studies in plants, and it can be coupled successfully to other analytical techniques.

中文翻译：

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X射线荧光光谱法（XRF）应用于植物科学：植物体内分析面临的挑战。

X射线荧光光谱（XRF）是一种分析工具，用于确定大量样品基质中的元素组成。由于XRF的非破坏性功能，该技术可以在体内条件下进行时间分辨的植物组织分析，此外还可以与其他非破坏性技术结合使用。在这项研究中，我们使用了手持式和台式XRF装置来评估暴露于X射线的活植物组织中元素的分布变化，以及大豆中Zn _（aq）和Mn _（aq）的实时吸收动力学（Glycine max（L.）Merrill）茎和叶，持续48小时，并通过红外气体分析仪（IRGA）评估叶上的蒸腾速率。我们发现茎中的锌含量高于锰。反过来，后者的微量营养素在叶脉中的浓度更高。此外，两种微量营养素都更集中在大豆植物的第一三叶草（即最年轻的叶子）中。此外，蒸腾速率受昼夜节律的影响比吸收锌和锰的影响更大。因此，XRF代表了一种用于植物体内营养研究的便捷工具，并且可以成功地与其他分析技术结合。