Description:
Aloin is an irritant laxative contained in the yellow sap of Aloe,which is a constituent of the Anthraquinone Complex.Aloin is an irritant laxative contained in the yellow sap ofAloe, which is a constituent of the Anthraquinone Complex.
Aloin, a kind of anthraquinone, is a chemical component in Aloeleaves used in medicine. The processes of aloin production,transport and storage were studied with a transmission electronmicroscope using the lead acetate precipitate method forultracytochemical localization of aloin in the leaf of Aloearborescens Mill. Results showed that aloin was produced in theplastids of the assimilating tissue, transported through theplastid membrane to the surrounding endoplasmic reticulum andenveloped in the vesicles by the endoplasmic reticulum elements.The vesicles approached, and later fused with, the plasmalemma,released their contents into the apoplast through exocytosis andfinally, reached the vascular bundle sheath by apoplastictranslocation. Aloin was transported to the internal tangentialwall of the vascular bundle sheath cell through endoplasmicreticulum vesicles, and reached the cytoplasm of the aloin cell bymeans of plasmodesmata. Finally, aloin was stored in the vacuole ofthe cell in which it was produced
