Pauly N, Knight M R, Thuleau P, Graziana A, Muto S, Ranjeva R, Mazars C
Signaux et Messages Cellulaires chez les Végétaux, Centre National de la Recherche Scientifique, Université Paul Sabatier, Castanet-Tolosan, France.
Cell Calcium. 2001 Dec;30(6):413-21. doi: 10.1054/ceca.2001.0250.
Plant cell suspension cultures respond to osmotic changes by alterations in levels of free cellular calcium. Using the aequorin recombinant method, we have measured the spatial and temporal characteristics of calcium signatures in the nucleus and the cytosol of BY-2 tobacco suspension cells challenged with hypo- or hyper-osmotic shock. We show here that the nuclear compartment contributes together with the cytosol to produce calcium signal patterns that discriminate hypo- from hyper-osmotic treatments, i.e. turgor from tension. We also demonstrate that calcium responses in the nucleus and the cytosol are differentially modulated by the strength and the nature of hyper-osmotic treatments. We conclude that qualitative and quantitative changes in the parameters of an external stimulus such as osmotic changes are converted into calcium signatures, distinctive in their temporal and subcellular characteristics, involving both the nucleus and the cytosol. Our results illustrate the versatility of calcium signaling in plant cells. In addition to the physiological 'address' of the cell, the compartmentation of the calcium signal is probably an important parameter in encoding response specificity.
植物细胞悬浮培养物通过细胞内游离钙水平的变化对渗透压变化做出反应。使用水母发光蛋白重组方法，我们测量了受到低渗或高渗冲击的BY-2烟草悬浮细胞核和细胞质中钙信号的时空特征。我们在此表明，核区室与细胞质共同作用，产生区分低渗处理和高渗处理的钙信号模式，即膨压与张力。我们还证明，高渗处理的强度和性质对细胞核和细胞质中的钙反应有不同的调节作用。我们得出结论，外部刺激参数（如渗透压变化）的定性和定量变化会转化为钙信号，其时间和亚细胞特征独特，涉及细胞核和细胞质。我们的结果说明了植物细胞中钙信号传导的多功能性。除了细胞的生理“地址”外，钙信号的区室化可能是编码反应特异性的一个重要参数。
