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Increase in cytoplasmic calcium content in internodal cells of Lamprothamnium upon hypotonic treatment
Author(s) -
OKAZAKI Y.,
TAZAWA M.
Publication year - 1987
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/1365-3040.ep11604134
Subject(s) - turgor pressure , tonicity , osmotic pressure , calcium , cytoplasm , osmoregulation , biophysics , cytoplasmic streaming , chemistry , biology , biochemistry , botany , microbiology and biotechnology , salinity , ecology , organic chemistry
Internodal cells of Lamprothamnium succinctum , a brackish water Characeae, regulate turgor pressure in response to changes in external osmotic pressure (turgor regulation). When internodal cells were transferred to a hypotonic medium containing 3.9 mol m −3 Ca 2+ , the cell osmotic pressure decreased and the original turgor pressure was recovered. During turgor regulation Ca content of the cytoplasm increased significantly. Lowering the external Ca 2+ concentration from 3.9 to 0.01 mol m −3 inhibited this increase in cytoplasmic calcium content. In a hypotonic medium containing 0.01 mol m −3 Ca 2+ , turgor regulation was inhibited as previously reported (Okazaki & Tazawa, 1986a). Thus transient increase in cytoplasmic Ca, probably in the ionized form, induced by hypotonic treatment may play an important role in turgor regulation.