Ultrastructure of acridone alkaloid idioblasts in roots and cell cultures of Ruta graveolens

Abstract

Histological analysis of Ruta graveolens L. roots and in vitro grown cell suspensions revealed idioblasts with vacuoles containing clusters of droplets thought to be the storage compartment of acridone alkaloids. These idioblasts contained numerous vacuoles of varying sizes rather than the large, single, central vacuole characteristic of most adjacent parenchyma cells. The structure of idioblasts in roots and suspension cultures was identical. Treatment of suspension cultures with fungal elicitors known to increase alkaloid accumulation greatly did not affect the structure of idioblasts.