texas-red and inositol-1-4-5-trisphosphate-1-(2-nitrophenyl)ethyl-ester

Plant cells can respond qualitatively and quantitatively to a wide range of environmental signals. Ca(2+) is used as an intracellular signal for volume regulation in response to external osmotic changes. We show here that the spatiotemporal patterns of hypo-osmotically induced Ca(2+) signals vary dramatically with stimulus strength in embryonic cells of the marine alga Fucus. Biphasic or multiphasic Ca(2+) signals reflect Ca(2+) elevations in distinct cellular domains. These propagate via elemental Ca(2+) release in nuclear or peripheral regions that are rich in endoplasmic reticulum. Cell volume regulation specifically requires Ca(2+) elevation in apical peripheral regions, whereas an altered cell division rate occurs only in response to stimuli that cause Ca(2+) elevation in nuclear regions.

Topics: Calcium; Calcium Signaling; Cell Division; Cell Size; Cells, Cultured; Eukaryota; Fluorescent Dyes; Inositol 1,4,5-Trisphosphate; Light; Microscopy, Confocal; Organic Chemicals; Osmotic Pressure; Xanthenes