Paxillus involutus Strains MAJ and NAU Mediate K+/Na+ Homeostasis in Ectomycorrhizal Populus x canescens under Sodium Chloride Stress
Paxillus involutus Strains MAJ and NAU Mediate K+/Na+ Homeostasis in Ectomycorrhizal Populus x canescens under Sodium Chloride Stress
复制标题
卷变桩霉菌株 MAJ 和 NAU 介导氯化钠胁迫下外生菌根杨 x 的 K / Na 稳态
DOI：
10.1104/pp.112.195370
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发表时间：
2012-08-01
期刊：
影响因子：
7.4
通讯作者：
Chen, Shaoliang
中科院分区：
文献类型：
--
作者：
Li, Jing;Bao, Siqin;Chen, Shaoliang
研究了盐胁迫下，渐开线桩孢菌（Paxillusinvolutus，MAJ和NAU）与盐敏感白杨杂交杨（Populusxcanescens）形成的外生菌根（EM）中H+、Na+、K+和Ca 2+的通量。使用扫描离子选择性电极技术测量两种渐开线羊肚菌分离物的非EM根和无菌生长的EM培养物中的通量分布，以鉴定在EM根中检测到的主要改变是否由真菌伴侣促进。EM植物在盐胁迫下表现出更明显的维持K+/Na+稳态的能力。短期（50 mM NaCl，24 h）和长期（50 mM NaCl，7 d）暴露于盐胁迫下的菌根根，特别是NAU协会的Na+的流入减少。通量数据的P. involutus和敏感性的Na+转运抑制剂表明，真菌的殖民化有助于积极的Na+挤出和H+吸收的P. x canescens盐渍化的根。此外，EM植物保留的能力，以减少盐诱导的K+外流，特别是在长期的盐度。我们的研究表明，在盐胁迫下，渐开线拟青霉通过将这种营养物质输送到宿主植物并减缓K+的损失来帮助维持K+的稳态。EMP. x canescens植物表现出增强的Ca 2+吸收能力，而短期和长期处理引起了显着的Ca 2+流出菌根根，特别是从NAU定殖的根。我们认为，额外的Ca 2+的释放介导的K+/Na+稳态EM植物在盐胁迫下。
Salt-induced fluxes of H+, Na+, K+, and Ca2+ were investigated in ectomycorrhizal (EM) associations formed by Paxillus involutus (strains MAJ and NAU) with the salt-sensitive poplar hybrid Populus x canescens. A scanning ion-selective electrode technique was used to measure flux profiles in non-EM roots and axenically grown EM cultures of the two P. involutus isolates to identify whether the major alterations detected in EM roots were promoted by the fungal partner. EM plants exhibited a more pronounced ability to maintain K+/Na+ homeostasis under salt stress. The influx of Na+ was reduced after short-term (50 mM NaCl, 24 h) and long-term (50 mM NaCl, 7 d) exposure to salt stress in mycorrhizal roots, especially in NAU associations. Flux data for P. involutus and susceptibility to Na+-transport inhibitors indicated that fungal colonization contributed to active Na+ extrusion and H+ uptake in the salinized roots of P. x canescens. Moreover, EM plants retained the ability to reduce the salt-induced K+ efflux, especially under long-term salinity. Our study suggests that P. involutus assists in maintaining K+ homeostasis by delivering this nutrient to host plants and slowing the loss of K+ under salt stress. EM P. x canescens plants exhibited an enhanced Ca2+ uptake ability, whereas short-term and long-term treatments caused a marked Ca2+ efflux from mycorrhizal roots, especially from NAU-colonized roots. We suggest that the release of additional Ca2+ mediated K+/Na+ homeostasis in EM plants under salt stress.