Richit José Fernando, Kuhn Sofia Aumond
Laboratory of Plant Anatomy, Department of Botany, Institute of Biosciences, Federal University of Rio Grande Do Sul, Avenida Bento Gonçalves, Porto Alegre, 9500, Rio Grande do Sul, Brazil.
Sector of Biological Sciences, Federal University of Paraná, Avenida Coronel. Francisco H. dos Santos, 100, Curitiba, Paraná, Brazil.
Protoplasma. 2025 Apr 3. doi: 10.1007/s00709-025-02063-z.
Rutaceae plants are a rich source of alkaloids, but their cell-specific localization remains relatively unknown in the underground tissues, except for the acridone-containing idioblasts in Ruta graveolens roots. To fill this gap, we used broad taxonomic sampling to investigate both the microchemistry and the root structure of Rutaceae species. Utilizing both transmitted light and epifluorescence microscopy, we examined seven distinct Rutaceae species to determine if root idioblasts were present. For the microchemical analysis of the idioblasts contents, we employed Nile red staining and Dragendorff's test. All analyzed species presented root idioblasts with contents that are reactive with Dragendorff's reagent and Nile red, suggesting the presence of putative alkaloids and lipophilic environments, respectively. These idioblasts are typically found in the radicular cortex and can be easily observed under UV light due to their autofluorescent contents. We found that the occurrence of root idioblasts is a widely distributed condition in Rutaceae, showing for the first time both structural and microchemical analyses for broad taxonomic sampling. These cell types could play an important role in alkaloid metabolism in the underground tissues of plants in this family and offer an exciting opportunity for future investigations.
芸香科植物是生物碱的丰富来源，但除了芸香根中含吖啶酮的异细胞外，其在地下组织中的细胞特异性定位仍相对未知。为了填补这一空白，我们采用广泛的分类取样来研究芸香科物种的微化学和根系结构。利用透射光和落射荧光显微镜，我们检查了七个不同的芸香科物种，以确定根中是否存在异细胞。对于异细胞内容物的微化学分析，我们采用了尼罗红染色和碘化铋钾试验。所有分析的物种都呈现出根异细胞，其内容物分别与碘化铋钾试剂和尼罗红发生反应，表明分别存在推定的生物碱和亲脂性环境。这些异细胞通常存在于根皮层中，由于其自身荧光内容物，在紫外光下很容易观察到。我们发现根异细胞的出现是芸香科中广泛分布的一种情况，首次展示了广泛分类取样的结构和微化学分析。这些细胞类型可能在该科植物地下组织的生物碱代谢中发挥重要作用，并为未来的研究提供了一个令人兴奋的机会。
