title: Morphological and ultrastructural changes in tobacco BY-2 cells exposed to microcystin-RR.
abstract: Tobacco BY-2 cells were exposed to microcystin-RR (MC-RR) at two concentrations, 60 microg mL(-1) and 120 microg mL(-1), to study the changes in morphology and ultrastructure of cells as a result of the exposure. Exposure to the lower concentration for 5 d led to typical apoptotic morphological changes including condensation of nuclear chromatin, creation of a characteristic 'half moon' structure, and cytoplasm shrinkage and decreased cell volume, as revealed through light microscopy, fluorescence microscopy, and transmission electron microscopy, respectively. Exposure to the higher concentration, on the other hand, led to morphological and ultrastructural changes typical of necrosis, such as rupture of the plasma membrane and the nuclear membrane and a marked swelling of cells. The presence of many vacuoles containing unusual deposits points to the involvement of vacuoles in detoxifying MC-RR. Results of the present study indicate that exposure of tobacco BY-2 cells to MC-RR at a lower concentration (60 microg mL(-1)) results in apoptosis and that to a higher concentration (120 microg mL(-1)), in necrosis.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
authors.forename: Wenmin
authors.initials: W
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Xing
authors.forename: Dunhai
authors.initials: D
authors.lastname: Li
authors.forename: Yongding
authors.initials: Y
authors.lastname: Liu
mesh_terms: D017209:Apoptosis; D002462:Cell Membrane / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D002478:Cells, Cultured; D003593:Cytoplasm / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D008387:Marine Toxins; D052998:Microcystins / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000648:ultrastructure; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D014873:Water Pollutants / Q000633:toxicity*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D014873:Water Pollutants; C063855:microcystin RR