The ability of phenolic compounds to autofluoresce upon illumination by UV or blue light was exploited to explore the nature and distribution of these metabolites within the flower petals, leaves and roots of the violet, Viola alba subsp. dehnhardtii. This was achieved through a dual complementary approach that combined fluorescence microscopy imaging of living intact tissues and chemical extraction of pulverized material. The blue to red fluorescence displayed by living tissues upon illumination was indicative of their richness in phenolic compounds. Phenolic acids were found in all tissues, while flavonoids characterized the aerial part of the plant, anthocyanidins being restricted to the petals. The chemical quantification of phenolics in plant extracts confirmed their tissue-specific distribution and abundance. A key finding was that the spectral signatures obtained through confocal microscopy of endogenous fluorophores in living tissues and their counterpart extracts share the same fluorescence patterns, pointing out the potential of fluorescence imaging of intact organs for a proper estimation of their phenolic content. In addition, this study highlighted a few distinct morphology cell types, in particular foliar-glandular-like structures, and jagged petal cell walls. Altogether, these data provide a comprehensive histochemical localization of phenolics in living tissues of a violet. Converting fluorescence imaging into a chemical imprint indicated that one can rely on fluorescence microscopy of intact living tissues as a rapid, non-destructive means to follow their phenolic imprint under various environmental conditions.

中文翻译：

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化学和荧光成像揭示了帕尔马紫的酚类成分

利用酚类化合物在紫外线或蓝光照射下自发荧光的能力来探索这些代谢物在紫罗兰、Viola alba subsp.的花瓣、叶子和根中的性质和分布。德哈蒂。这是通过双重互补方法实现的，该方法将活的完整组织的荧光显微镜成像和粉碎材料的化学提取相结合。活组织在光照下显示的蓝色至红色荧光表明它们富含酚类化合物。在所有组织中都发现了酚酸，而类黄酮是植物地上部分的特征，花青素仅限于花瓣。植物提取物中酚类物质的化学定量证实了它们的组织特异性分布和丰度。一个关键发现是，通过活组织中内源性荧光团及其对应提取物的共聚焦显微镜获得的光谱特征具有相同的荧光模式，指出了完整器官的荧光成像在正确估计其酚类含量方面的潜力。此外，这项研究强调了一些不同的形态细胞类型，特别是叶状腺样结构和锯齿状的花瓣细胞壁。总之，这些数据提供了紫罗兰活组织中酚类物质的全面组织化学定位。将荧光成像转换为化学印记表明，人们可以依靠完整活组织的荧光显微镜作为一种快速、非破坏性的手段，在各种环境条件下追踪其酚类印记。