Figueiredo Maria Gabriela Ferreira, Ribeiro Leonardo Monteiro, Mercadante-Simões Maria Olívia
Departamento de Biologia Geral, Universidade Estadual de Montes Claros, Montes Claros, 39401-089, Brazil.
Protoplasma. 2025 Mar;262(2):353-363. doi: 10.1007/s00709-024-01999-y. Epub 2024 Oct 17.
Laticifers are secretive structures with important roles in controlling abiotic and biotic stress through the external release of viscous and bioactive latex emulsions composed of alkaloids, terpenes, flavonoids, proteins, and mucilage. Allamanda cathartica is an attractive ornamental neotropical shrub that produces abundant latex with medicinal potential. The laticifers of this species, their origins, structural types, and distribution in the primary and secondary structures of the stem were investigated, and the chemical nature of latex was determined. Anatomical, histochemical, and ultrastructural evaluations of the stem apex were performed through light and electronic microscopy. Laticifers are abundant in the primary structure, being distributed in the cortex, outer primary phloem, and pith. Their branching, anastomosing structural type develops by the dissolution of the transverse and lateral walls of precursor meristematic cells, followed by protoplast fusion. The laticifers in the secondary structure are distributed amid the axial parenchyma cells of the phloem. The latex of A. cathartica is an emulsion composed mainly of mucilage and terpenes, and it is the first time that this laticifer system has been described.
乳汁管是一种隐秘的结构，通过向外释放由生物碱、萜类、黄酮类、蛋白质和黏液组成的黏性生物活性乳胶乳液，在控制非生物和生物胁迫方面发挥着重要作用。黄蝉是一种引人注目的新热带观赏灌木，能产生具有药用潜力的大量乳胶。对该物种的乳汁管、其起源、结构类型以及在茎的初生和次生结构中的分布进行了研究，并确定了乳胶的化学性质。通过光学显微镜和电子显微镜对茎尖进行了解剖学、组织化学和超微结构评估。乳汁管在初生结构中丰富，分布在皮层、初生韧皮部外层和髓中。它们的分支、吻合结构类型是由前体分生组织细胞的横向和侧壁溶解，随后原生质体融合形成的。次生结构中的乳汁管分布在韧皮部的轴向薄壁细胞之间。黄蝉的乳胶是一种主要由黏液和萜类组成的乳液，这是首次对这种乳汁管系统进行描述。
