盐生植物中氯化钠毒性与耐盐性的细胞基础
Sodium chloride toxicity and the cellular basis of salt tolerance in halophytes.
作者信息
Flowers Timothy J, Munns Rana, Colmer Timothy D
机构信息
School of Plant Biology and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia, CSIRO Agriculture, GPO Box 1600, Canberra, ACT, 2601, Australia and School of Life Sciences, University of Sussex, Falmer, Brighton BN7 1BD, UK School of Plant Biology and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia, CSIRO Agriculture, GPO Box 1600, Canberra, ACT, 2601, Australia and School of Life Sciences, University of Sussex, Falmer, Brighton BN7 1BD, UK
School of Plant Biology and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia, CSIRO Agriculture, GPO Box 1600, Canberra, ACT, 2601, Australia and School of Life Sciences, University of Sussex, Falmer, Brighton BN7 1BD, UK School of Plant Biology and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia, CSIRO Agriculture, GPO Box 1600, Canberra, ACT, 2601, Australia and School of Life Sciences, University of Sussex, Falmer, Brighton BN7 1BD, UK School of Plant Biology and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia, CSIRO Agriculture, GPO Box 1600, Canberra, ACT, 2601, Australia and School of Life Sciences, University of Sussex, Falmer, Brighton BN7 1BD, UK.
出版信息
Ann Bot. 2015 Feb;115(3):419-31. doi: 10.1093/aob/mcu217. Epub 2014 Dec 1.
BACKGROUND
Halophytes are the flora of saline soils. They adjust osmotically to soil salinity by accumulating ions and sequestering the vast majority of these (generally Na(+) and Cl(-)) in vacuoles, while in the cytoplasm organic solutes are accumulated to prevent adverse effects on metabolism. At high salinities, however, growth is inhibited. Possible causes are: toxicity to metabolism of Na(+) and/or Cl(-) in the cytoplasm; insufficient osmotic adjustment resulting in reduced net photosynthesis because of stomatal closure; reduced turgor for expansion growth; adverse cellular water relations if ions build up in the apoplast (cell walls) of leaves; diversion of energy needed to maintain solute homeostasis; sub-optimal levels of K(+) (or other mineral nutrients) required for maintaining enzyme activities; possible damage from reactive oxygen species; or changes in hormonal concentrations.
SCOPE
This review discusses the evidence for Na(+) and Cl(-) toxicity and the concept of tissue tolerance in relation to halophytes.
CONCLUSIONS
The data reviewed here suggest that halophytes tolerate cytoplasmic Na(+) and Cl(-) concentrations of 100-200 mm, but whether these ions ever reach toxic concentrations that inhibit metabolism in the cytoplasm or cause death is unknown. Measurements of ion concentrations in the cytosol of various cell types for contrasting species and growth conditions are needed. Future work should also focus on the properties of the tonoplast that enable ion accumulation and prevent ion leakage, such as the special properties of ion transporters and of the lipids that determine membrane permeability.
背景
盐生植物是盐渍土壤中的植物群落。它们通过积累离子并将其中绝大多数（通常是Na⁺和Cl⁻）隔离在液泡中来进行渗透调节，而在细胞质中积累有机溶质以防止对新陈代谢产生不利影响。然而，在高盐度条件下，生长会受到抑制。可能的原因包括：细胞质中Na⁺和/或Cl⁻对新陈代谢产生毒性；渗透调节不足，由于气孔关闭导致净光合作用降低；膨压降低影响扩展生长；如果离子在叶片的质外体（细胞壁）中积累，细胞水分关系会受到不利影响；维持溶质稳态所需的能量被转移；维持酶活性所需的K⁺（或其他矿质营养）水平不理想；活性氧可能造成的损害；或激素浓度的变化。
范围
本综述讨论了与盐生植物相关的Na⁺和Cl⁻毒性证据以及组织耐受性的概念。
结论
这里回顾的数据表明，盐生植物能够耐受细胞质中100 - 200 mM的Na⁺和Cl⁻浓度，但这些离子是否会达到抑制细胞质新陈代谢或导致死亡的有毒浓度尚不清楚。需要针对不同物种和生长条件测量各种细胞类型细胞质中的离子浓度。未来的工作还应关注液泡膜的特性，这些特性能够实现离子积累并防止离子泄漏，例如离子转运体的特殊性质以及决定膜通透性的脂质的特殊性质。
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