Effects of a homogeneous linear alcohol ethylene oxide surfactant on the ultrastructure of soybean cell suspension cultures

Abstract

Ultrastructural alterations of soybean cell suspension cultures treated with a homogeneous linear alcohol ethylene oxide nonionic surfactant, the octa(oxyethylene) adduct of 1-dodecanol (at concentrations below the critical micelle concentration), were determined at 0.5, 3, and 10 days. Treatments were 4 μM (2 ppm; nonphytotoxic), 11 to 17 μM (6 to 9 ppm; inhibitory), and 28 μM (15 ppm; phytotoxic). Plastids and mitochondria appeared to have reduced amounts of internal membranes at 0.5 days, even at sublethal concentrations. At 3 days after treatment, cells treated with up to 17 μM detergent looked similar to control cells, except for void regions in some organelles. Cells treated 0.5 days with 28 μM had plastids with few membranes and much reduced starch compared with controls; by 3 days, these cells were badly damaged, although numerous organelles still could be recognized and lipid bodies were spherical. Distinctive myelin-like membrane whorls were present in some 3-day 28 μM treated cells. Even at 10 days recognizable organelles in cells included nuclei, plastids, some endoplasmic reticulum and some flattened nuclei with irregularly shaped nucleoli. Starch granules were conspicuously free of the plastids in which they were formed. Lipid bodies were often angular in shape rather than spherical. Outer envelopes of organelles often remained, even though their internal structures were destroyed or altered greatly.