The University of Queensland, School of Land, Crop and Food Sciences, St. Lucia, Qld 4072, Australia.
Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), The University of Queensland, St. Lucia, Qld 4072, Australia.
New Phytol. 2011 Mar;189(4):1110-1121. doi: 10.1111/j.1469-8137.2010.03551.x. Epub 2010 Nov 30.
• Reductions in plant growth as a result of salinity are of global importance in natural and agricultural landscapes. • Short-term (48-h) solution culture experiments studied 404 treatments with seedlings of cowpea (Vigna unguiculata cv Caloona) to examine the multiple deleterious effects of calcium (Ca), magnesium (Mg), sodium (Na) or potassium (K). • Growth was poorly related to the ion activities in the bulk solution, but was closely related to the calculated activities at the outer surface of the plasma membrane, {I(z)}₀°. The addition of Mg, Na or K may induce Ca deficiency in roots by driving {Ca²+}₀° to < 1.6 mM. Shoots were more sensitive than roots to osmolarity. Specific ion toxicities reduced root elongation in the order Ca²+ > Mg²+ > Na+ > K+. The addition of K and, to a lesser extent, Ca alleviated the toxic effects of Na. Thus, Ca is essential but may also be intoxicating or ameliorative. • The data demonstrate that the short-term growth of cowpea seedlings in saline solutions may be limited by Ca deficiency, osmotic effects and specific ion toxicities, and K and Ca alleviate Na toxicity. A multiple regression model related root growth to osmolarity and {I(z)}₀° (R²=0.924), allowing the quantification of their effects.
• 由于盐分导致的植物生长减少在自然和农业景观中具有全球重要性。 • 短期（48 小时）溶液培养实验研究了 404 种豇豆（Vigna unguiculata cv Caloona）幼苗的处理方法，以研究钙（Ca）、镁（Mg）、钠（Na）或钾（K）的多种有害影响。 • 生长与大量溶液中的离子活度关系不大，但与质膜外表面的计算活度{I（z）}₀°密切相关。添加 Mg、Na 或 K 可能通过将{Ca²+}₀°驱动至<1.6 mM 来诱导根部的 Ca 缺乏。与根相比，芽对渗透压更敏感。特定离子毒性按 Ca²+>Mg²+>Na+>K+的顺序降低根伸长。添加 K 以及在较小程度上添加 Ca 缓解了 Na 的毒性作用。因此，Ca 是必需的，但也可能是中毒或改善的。 • 数据表明，在盐溶液中豇豆幼苗的短期生长可能受到 Ca 缺乏、渗透压和特定离子毒性以及 K 和 Ca 缓解 Na 毒性的限制。一个多元回归模型将根生长与渗透压和{I（z）}₀°相关联（R²=0.924），允许量化它们的影响。
