| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1987: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
The present study aimed to examine the suitability of the protoplast system for testing effects of various surfactants on living cells. Protoplasts prepared from cucumber leaves and hyphae of cucumber anthracnose fungus, Colletotrichum lagenarium, were treated with 4 nonionic and 2 anionic surfactants. Test nonionic surfactants were divided into 2 groups on the basis of their effects: 2 of them did not give any detectable effects to both cucumber and fungus protoplasts, while other 2 caused swelling of protoplasts, followed by their bursting. Thus, the latter 2 perhaps interfere with permeability of plasma membrane. Two anionic surfactants caused the sudden bursting of protoplasts immediately after the onset of treatment, suggesting that they way directly damage the structure of plasma membrane. The effects of the respective surfactants on membranes varied among organelles: especially membranes of mitochondrial cristae and chloroplast granae were sensitive to some surfactants . The treatment of intact cotyledons of cucumber with the respective surfactants revealed that the cuticle layer covering the cotyledon surfaces suppressed the permeability of some surfactants. Therefore, when intact cotyledons were treated with the respective surfactants, cotyledon cells were not affected by most surfactants. However, when the lower surfaces of stripped epidermises which had no cuticle were treated, their cells responded similarly as protoplasts. Similar results were obtained when spores of the fungus were treated with the surfactants. These results suggest that the presence of cell walls may not be a negative factor for permeability of the surfactants. In conclusion, the protoplast system is a propers sensitive system for analyzing the direct, cytological effects of surfactants on living cells, although time and labor are required for preparing protoplasts. However, the permeability of surfactants through cuticles should be examined by a separate method.
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