Department of Biology, University of York, York YO10 5DD, UK.
J Exp Bot. 2014 Mar;65(3):849-58. doi: 10.1093/jxb/ert326. Epub 2013 Oct 22.
Although not essential for most plants, sodium (Na(+)) can be beneficial to plants in many conditions, particularly when potassium (K(+)) is deficient. As such it can be regarded a 'non-essential' or 'functional' nutrient. By contrast, the many salinized areas around the globe force plants to deal with toxicity from high levels of Na(+) in the environment and within tissues. Progress has been made in identifying the relevant membrane transporters involved in the uptake and distribution of Na(+). The latter is important in the context of mitigating salinity stress but also for the optimization of Na(+) as an abundantly available functional nutrient. In both cases plants are likely to require mechanism(s) to monitor Na(+) concentration, possibly in multiple compartments, to regulate gene expression and transport activities. Extremely little is known about whether such mechanisms are present and if so, how they operate, either at the cellular or the tissue level. This paper gives an overview of the regulatory and potential sensing mechanisms that pertain to Na(+), in both the context of salt stress and Na(+) as a nutrient.
虽然钠（Na(+)）对大多数植物并非必需，但在许多情况下，特别是在钾（K(+)）缺乏的情况下，它对植物有益。因此，它可以被视为一种“非必需”或“功能性”营养物质。相比之下，全球许多盐渍地区迫使植物应对环境中和组织内高浓度 Na(+)的毒性。在确定与 Na(+)摄取和分布相关的相关膜转运蛋白方面已经取得了进展。在后一种情况下，减轻盐胁迫很重要，但优化 Na(+)作为丰富的功能性营养物质也很重要。在这两种情况下，植物可能都需要监测 Na(+)浓度的机制，可能在多个隔室中，以调节基因表达和转运活性。对于这些机制是否存在以及如果存在，它们如何在细胞或组织水平上运作，人们知之甚少。本文概述了与盐胁迫和 Na(+)作为营养物质有关的 Na(+)的调节和潜在感应机制。
