Lorenzen Inken, Aberle Thomas, Plieth Christoph
Zentrum für Biochemie und Molekularbiologie, Universität Kiel, Am Botanischen Garten 9, 24118 Kiel, Germany.
Plant J. 2004 May;38(3):539-44. doi: 10.1111/j.0960-7412.2004.02053.x.
Salt stress leads to massive accumulation of toxic levels of Na(+) and Cl(-) ions in plants. By using the recombinant fluorescent probe CLOMELEON, we demonstrate passive anion flux under salt stress. Chloride influx is restricted in the presence of divalent cations like Mg(2+) and Ca(2+), and completely blocked by La(3+). The amount but not the rate of the reported chloride uptake is independent from the kind of corresponding permeable cation (K(+) versus Na(+)), external pH and magnitude of osmotic stress. Cl(-) efflux however seems to involve stretch-activated transport. From the influence of Ca(2+) on reported changes of cytosolic anion concentrations, we speculate that transport mechanisms of Cl(-) and Na(+) might be thermodynamically coupled under saline conditions.
盐胁迫导致植物中有毒水平的Na⁺和Cl⁻离子大量积累。通过使用重组荧光探针变色龙（CLOMELEON），我们证明了盐胁迫下的被动阴离子通量。在Mg²⁺和Ca²⁺等二价阳离子存在的情况下，氯离子内流受到限制，并被La³⁺完全阻断。所报道的氯离子吸收量而非速率与相应可渗透阳离子（K⁺与Na⁺）的种类、外部pH值和渗透胁迫的大小无关。然而，Cl⁻外流似乎涉及拉伸激活转运。从Ca²⁺对所报道的胞质阴离子浓度变化的影响来看，我们推测在盐渍条件下Cl⁻和Na⁺的转运机制可能在热力学上是耦合的。
