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NMT历史上的今天丨Front Plant Sci:Paxillus involutus促进Cd2+吸收机制

转自中关村旭月非损伤微测技术产业联盟

NMT历史上的今天

2017年01月06日,北京林业大学陈少良、张玉红用NMT在Frontiers in Plant Science上发表了标题为Paxillus involutus-Facilitated Cd2+ Influx through Plasma Membrane Ca2+-Permeable Channels Is Stimulated by H2O2 and H+-ATPase in Ectomycorrhizal Populus × canescens under Cadmium Stress的研究成果。

 

  • 期刊:Frontiers in Plant Science
  • 主题:Paxillus involutus促进Cd2+吸收机制
  • 标题:Paxillus involutus-Facilitated Cd2+ Influx through Plasma Membrane Ca2+-Permeable Channels Is Stimulated by H2O2 and H+-ATPase in Ectomycorrhizal Populus × canescens under Cadmium Stress
  • 影响因子:4.495
  • 检测指标:H+、Ca2+、Cd2+、H2O2流速
  • 通讯作者:北京林业大学陈少良、张玉红

英文摘要

Using a Non-invasive Micro-test Technique, flux profiles of Cd2+, Ca2+, and H+ were investigated in axenically grown cultures of two strains of Paxillus involutus (MAJ and NAU), ectomycorrhizae formed by these fungi with the woody Cd2+-hyperaccumulator, Populus × canescens, and non-mycorrhizal (NM) roots.

The influx of Cd2+ increased in fungal mycelia, NM and ectomycorrhizal (EM) roots upon a 40-min shock, after short-term (ST, 24 h), or long-term (LT, 7 days) exposure to a hydroponic environment of 50 μM CdCl2. Cd2+ treatments (shock, ST, and LT) decreased Ca2+ influx in NM and EM roots but led to an enhanced influx of Ca2+ in axenically grown EM cultures of the two P. involutus isolates.

The susceptibility of Cd2+ flux to typical Ca2+ channel blockers (LaCl3, GdCl3, verapamil, and TEA) in fungal mycelia and poplar roots indicated that the Cd2+ entry occurred mainly through Ca2+-permeable channels in the plasma membrane (PM). Cd2+ treatment resulted in H2O2 production. H2O2 exposure accelerated the entry of Cd2+ and Ca2+ in NM and EM roots. Cd2+ further stimulated H+ pumping activity benefiting NM and EM roots to maintain an acidic environment, which favored the entry of Cd2+ across the PM.

A scavenger of reactive oxygen species, DMTU, and an inhibitor of PM H+-ATPase, orthovanadate, decreased Ca2+ and Cd2+ influx in NM and EM roots, suggesting that the entry of Cd2+ through Ca2+-permeable channels is stimulated by H2O2 and H+ pumps. Compared to NM roots, EM roots exhibited higher Cd2+-fluxes under shock, ST, and LT Cd2+ treatments.

We conclude that ectomycorrhizal P. × canescens roots retained a pronounced H2O2 production and a high H+-pumping activity, which activated PM Ca2+ channels and thus facilitated a high influx of Cd2+ under Cd2+ stress.

中文摘要(谷歌机翻)

使用非损伤微测技术,研究了两株渐渐出现的新孢子虫(MAJ和NAU)的无性培养中Cd2+,Ca2+和H+的通量分布,这是由这些真菌与木质的Cd2+-超蓄积剂,胡杨形成的外生菌根 ×canescens和非菌根(NM)根。

短期(ST,24 h)或长期(LT,7天)暴露于水培环境的40分钟休克后,真菌菌丝体,NM和根外菌根(EM)根中Cd2+的流入增加。50μM氯化镉。Cd2+处理(电击,ST和LT)减少了NM和EM根中的Ca2+流入,但导致了两个渐近线对虾分离株的无性生长EM培养物中Ca2+的流入增加。

Cd2+通量对真菌菌丝体和杨树根中典型的Ca2+通道阻滞剂(LaCl3,GdCl3,维拉帕米和TEA)的敏感性表明,Cd2+进入主要通过质膜(PM)中的Ca2+渗透通道发生。Cd2+处理导致产生H2O2。H2O2暴露加速了NM和EM根中Cd2+和Ca2+的进入。Cd2+进一步刺激了H+的泵送活性,有利于NM和EM根系维持酸性环境,这有利于Cd2+跨PM进入。

活性氧清除剂DMTU和PM H+ -ATPase的抑制剂原钒酸盐减少了NM和EM根中Ca2+和Cd2+的内流,这表明H2O2和H+泵刺激了Cd2+通过Ca2+渗透性通道的进入。与NM根相比,EM根在电击,ST和LT Cd2+处理下表现出更高的Cd2+通量。

我们得出的结论是,外生根茎假单胞菌根保留了明显的H2O2产生和高H+泵送活性,从而激活了PM Ca2+通道,从而促进了Cd2+胁迫下Cd2+的大量涌入。

FIGURE 1 | Effects of CdCl2 on transient kinetics of Cd2+, Ca2+, and H+ in Populus × canescens roots and Paxillus involutus strains MAJ and NAU. Cd2+ (A), Ca2+ (B), and H+ (C) kinetics were recorded before and after the required amount of 50 µM CdCl2 was introduced into the measuring chamber.

文章链接:https://www.frontiersin.org/articles/10.3389/fpls.2016.01975/full