Ultrastructural and autoradiographic study of the intranuclear inclusions of Pinguicula lusitanica L.

Intranuclear inclusions are found in Pinguicula lusiaanica. Observations with an electron microscope equipped with a goniometric stage demonstrate that they are formed with numerous similarly oriented lamellae. Enzyme digestions of ultrathin sections show that the inclusions are composed of protein. An autoradiographic study, after incubation of pieces of leaves or roots in a physiological medium containing tritiated arginine, shows that the inclusions grow in tissue incubated in such an artificial mineral medium.