Effects of energetic shortage upon the ultrastructure o f some organelles, in excised roots of Lycopersicum esculentum cultivated in vitro. I. Reversible structural modifications of the endoplasmic reticulum.

Abstract

Impairments of the energy metabolism affect ultrastructures of the organelles in roots, during long-term anaerobiosis (72 h). They were fully reversible upon the return to an aerated medium (15 h). Comparison was made after uncoupling oxidative phosphorylation by means of the 2-4 DNP, [2,4-dinitrophenol] or after plasmolysis which reduced the O2 uptake. The endoplasmic reticulum saccules, which were located in the peripheric cytoplasm of control cells, were reduced during the 3 experiments, possibly associated with a diminution of the chemical exchanges from one cell to another. Other saccules formed long parallel sheets, their ribosomes remaining numerous. A complex system of anaerobiosis-induced vesicles formed in the perinuclear cytoplasm.