Kerstiens Gerhard, Tych Wlodek, Robinson Michael F, Mansfield Terry A
Department of Biological Sciences, Institute of Environmental and Natural Sciences, Lancaster University, Lancaster LA1 4YQ, UK.
New Phytol. 2002 Mar;153(3):509-515. doi: 10.1046/j.0028-646X.2001.00330.x. Epub 2002 Mar 5.
• When Aster tripolium is grown at high salinity, stomatal closure is induced by the presence of sodium ions in the apoplast surrounding the guard cells. The occurrence of this system in Aster tripolium and not in the closely related glycophyte Aster amellus suggests that it could be an important factor in the network of physiological attributes required for salt tolerance. • Gas exchange and growth parameters were measured in Aster tripolium plants grown at different levels of salinity. A simple mechanistic model was constructed to test whether the Na-sensing feature of the guard cells was a realistic component of salinity tolerance. • The model captured very well the behaviour of plants in terms of salt uptake and reduction of growth with increasing salinity. There was moderate variance between measured and modelled rates of decrease of conductance with increasing levels of salinity. • No evidence was found to refute our hypothesis that stomatal closure in response to sodium plays an important role in salt tolerance of Aster tripolium.
• 当海生紫菀在高盐度环境下生长时，保卫细胞周围质外体中的钠离子会诱导气孔关闭。这种系统存在于海生紫菀中，而在亲缘关系较近的甜土植物高山紫菀中却不存在，这表明它可能是耐盐所需生理特性网络中的一个重要因素。
• 对在不同盐度水平下生长的海生紫菀植株的气体交换和生长参数进行了测量。构建了一个简单的机理模型来测试保卫细胞的钠感知特性是否是耐盐性的一个实际组成部分。
• 该模型很好地捕捉了植物在盐分吸收以及随着盐度增加生长减少方面的行为。随着盐度水平的增加，测量得到的和模型模拟的导度降低速率之间存在适度差异。
• 没有证据反驳我们的假设，即对钠作出反应的气孔关闭在海生紫菀的耐盐性中起重要作用。
