Ultrastructure of vegetative internodal cells of Tolylypella intricata (Charales, Charophyta).

AMELIA VOUILLOUD,; LEONARDI PATRICIA,; CACERES, EDUARDO

Simposio; VI International Symposium on Extant and Fossil Charophytes,; 2012

INTRODUCTION The present is the first ultrastructural study performed in vegetative cells of a species of Tolypella. Descriptions of the ultrastructure of vegetative cells have been conducted in species of the genus Chara (2, 3, 4, 5, 6, 7, 8, 13,16). In Nitella some studies have been also done but focused on particular organelles (1, 9, 10, 12, 14, 15). RESULTS AND DISCUSSION The four-layered cell wall of Tolypella intrincata showed unique refractive lenticular thickenings whose ultrastructure is elucidated here for the first time. Owing to their unique morphology and their exclusive presence in the genus we proposed the name "tolysomes" for them. Tolysomes and charasomes can be considered, analogously to the periplasmic space defined by Franceschi and Lucas (7), structures related to the extreme size of Charales cells. Tolysomes greatly amplify the plasma membrane surface therefore defining particular spaces of the cytoplasm. Cells showed a single central vacuole like cells of Chara but not to a central multivacuolar system like cells of Nitella. Resting amitotic nuclei were C-shaped, similar to those described for young internodal cells of Chara (17) but different to the spindle-shaped nuclei of Nitella (11). Chloroplasts and mature echinoid bodies were entirely similar to those described previously in Chara and Nitella cells.