Raven John A
Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee, UK.
School of Plant Biology, University of Western Australia MO84, Stirling Highway. Crawley, WA, Australia.
J Exp Bot. 2017 Jan;38(3):359-367. doi: 10.1093/jxb/erw421. Epub 2016 Dec 30.
Cl− is an essential micronutrient for oxygenic photolithotrophs. About half of global primary productivity is carried out by oxygenic photolithotrophs exposed to saline waters with Cl− concentrations orders of magnitude higher than that needed to satisfy the micronutrient requirement. The other half of primary productivity involves terrestrial and freshwater glycophytes sometimes in environments containing significantly more Cl− than is needed for the micronutrient requirement, but less than the toxic Cl– concentration for glycophytes. Intracellular Cl− acts in regulation of cell turgor and volume, including that of stomatal and pulvinar nastic movements, is a major ion in streptophyte and ulvophycean action potentials, and is involved in ion currents flowing around apices of pollen tubes and Acetabularia cells. More work is needed on the essentiality of Cl− in these processes, as well as the recent finding that Cl− at 1–5 mol m−3 increases water use efficiency of growth and leaf area in Nicotiana tabacum.
氯离子是产氧光合自养生物必需的微量营养元素。全球大约一半的初级生产力是由暴露在盐水中的产氧光合自养生物进行的，这些盐水中的氯离子浓度比满足微量营养需求所需的浓度高出几个数量级。另一半初级生产力涉及陆地和淡水糖生植物，有时它们所处的环境中氯离子含量明显高于微量营养需求，但低于糖生植物的有毒氯离子浓度。细胞内的氯离子在调节细胞膨压和体积方面发挥作用，包括气孔和叶枕的感性运动，是链形植物和石莼属植物动作电位中的主要离子，并且参与花粉管和伞藻细胞顶端周围的离子电流。在这些过程中氯离子的必要性方面，以及最近发现1-5摩尔/立方米的氯离子可提高烟草生长和叶面积的水分利用效率方面，都需要开展更多研究。
