The Ultrastructure of Plasmodesmata in Sucking Scale inTillandsia

Abstract

An interpretation is reported on the ultrastructure of plasmodesmata that traverse in very large numbers the walls which separate the four central cells of the hair shield from the underlying dome-shaped cell in Tillandsia usneoides L. It is suggested that the endoplasmic reticulum traverses the plasmodesma, constituting the inner structure. This structure, owing to the sizes the reticulum should assume, would be granular (measures of the components are reported). This interpretation is useful better to understand the activity regulating the passage of substances from one cell to another.