NMT是基因功能的活體檢測(cè)技術(shù)，已被103位諾貝爾獎(jiǎng)得主所在單位，及北大、清華、中科院使用。

NMT歷史上的今天

2017年01月06日，北京林業(yè)大學(xué)陳少良、張玉紅用NMT在Frontiers in Plant Science上發(fā)表了標(biāo)題為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
主題：Paxillus involutus促進(jìn)Cd2+吸收機(jī)制

標(biāo)題：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

影響因子：4.495

檢測(cè)指標(biāo)：H+、Ca2+、Cd2+、H2O2流速

作者：北京林業(yè)大學(xué)陳少良、張玉紅

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 M 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（谷歌機(jī)翻）

使用非損傷微測(cè)技術(shù)，研究了兩株漸漸出現(xiàn)的新孢子蟲（MAJ和NAU）的無(wú)性培養(yǎng)中Cd2+，Ca2+和H+的通量分布，這是由這些真菌與木質(zhì)的Cd2+-超蓄積劑，胡楊形成的外生菌根 ×canescens和非菌根（NM）根。

短期（ST，24   h）或長(zhǎng)期（LT，7天）暴露于水培環(huán)境的40分鐘休克后，真菌菌絲體，NM和根外菌根（EM）根中Cd2+的流入增加。50 M氯化鎘。Cd2+處理（電擊，ST和LT）減少了NM和EM根中的Ca2+流入，但導(dǎo)致了兩個(gè)漸近線對(duì)蝦分離株的無(wú)性生長(zhǎng)EM培養(yǎng)物中Ca2+的流入增加。

Cd2+通量對(duì)真菌菌絲體和楊樹根中典型的Ca2+通道阻滯劑（LaCl3，GdCl3，維拉帕米和TEA）的敏感性表明，Cd2+進(jìn)入主要通過(guò)質(zhì)膜（PM）中的Ca2+滲透通道發(fā)生。Cd2+處理導(dǎo)致產(chǎn)生H2O2。H2O2暴露加速了NM和EM根中Cd2+和Ca2+的進(jìn)入。Cd2+進(jìn)一步刺激了H  +的泵送活性，有利于NM和EM根系維持酸性環(huán)境，這有利于Cd2+跨PM進(jìn)入。

活性氧清除劑DMTU和PM H+ -ATPase的抑制劑原釩酸鹽減少了NM和EM根中Ca2+和Cd2+的內(nèi)流，這表明H2O2和H+泵刺激了Cd2+通過(guò)Ca2+滲透性通道的進(jìn)入。與NM根相比，EM根在電擊，ST和LT Cd2+處理下表現(xiàn)出更高的Cd2+通量。

我們得出的結(jié)論是，外生根莖假單胞菌根保留了明顯的H2O2產(chǎn)生和高H+泵送活性，從而激活了PM Ca2+通道，從而促進(jìn)了Cd2+脅迫下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 M CdCl2was introduced