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NMT歷*的今天丨 鹽脅迫、重金屬脅迫 文章發表
NMT是基因功能的活體檢測技術，已被31位諾貝爾獎得主所在單位，及北大、清華、中科院使用。
NMT歷*的今天
2012年11月02日，河北師范大學崔素娟、王鵬利用NMT在Journal of Biological Chemistry 上發表了標題為A Na+ Ca2+ exchanger-like protein (AtNCL) involved in salt stress in Arabidopsis 的研究成果。
2016年11月02日，浙江大學李廷強、陶琦利用NMT在Journal of Experimental Botany 上發表了標題為The apoplasmic pathway via the root apex and lateral roots contributes to Cd hyperaccumulation in the hyperaccumulator Sedum alfredii的研究成果。
期刊：Journal of Biological Chemistry
主題：Na+ Ca2+交換蛋白樣蛋白（AtNCL）參與擬南芥的鹽脅迫
標題：A Na+ Ca2+ exchanger-like protein (AtNCL) involved in salt stress in Arabidopsis
影響因子：4.773
檢測指標：Ca2+流速
作者：河北師范大學崔素娟、王鵬
英文摘要
Calcium ions (Ca2+) play a crucial role in many key physiological processes; thus, the maintenance of Ca2+ homeostasis is of primary importance. Na+/Ca2+ exchangers (NCXs) play an important role in Ca2+ homeostasis in animal excitable cells.
Bioinformatic analysis of the Arabidopsis genome suggested the existence of a putative NCX gene, Arabidopsis NCX-like (AtNCL), encoding a protein with an NCX-like structure and different from Ca2+/H+ exchangers and Na+/H+ exchangers previously identified in plant. AtNCL was identified to localize in the Arabidopsis cell membrane fraction, have the ability of binding Ca2+, and possess NCX-like activity in a heterologous expression system of cultured mammalian CHO-K1 cells. AtNCL is broadly expressed in Arabidopsis, and abiotic stresses stimulated its transcript expression.
Loss-of-function atncl mutants were less sensitive to salt stress than wild-type or AtNCL transgenic overexpression lines. In addition, the total calcium content in whole atncl mutant seedlings was higher than that in wild type by atomic absorption spectroscopy. The level of free Ca2+ in the cytosol and Ca2+ flux at the root tips of atncl mutant plants, as detected using transgenic aequorin and a scanning ion-selective electrode, required a longer recovery time following NaCl stress compared with that in wild type.
All of these data suggest that AtNCL encodes a Na+/Ca2+ exchanger-like protein that participates in the maintenance of Ca2+ homeostasis in Arabidopsis. AtNCL may represent a new type of Ca2+ transporter in higher plants.
中文摘要（谷歌機翻）
鈣離子（Ca2+）在許多關鍵的生理過程中起著至關重要的作用。因此，維持Ca2+穩態至關重要。 Na+ / Ca2+交換子（NCXs）在動物可興奮細胞中的Ca2+穩態中起重要作用。
對擬南芥基因組的生物信息學分析表明，存在一個假定的NCX基因，擬南芥NCX樣（AtNCL），編碼一種具有NCX樣結構的蛋白質，不同于先前在植物中鑒定的Ca2+/ H+交換子和Na+ /H+交換子。 AtNCL被確定位于擬南芥細胞膜部分中，具有結合Ca2+的能力，并在培養的哺乳動物CHO-K1細胞的異源表達系統中具有類似NCX的活性。 AtNCL在擬南芥中廣泛表達，非生物脅迫刺激其轉錄本表達。
功能喪失的atncl突變體對鹽脅迫的敏感性不如野生型或AtNCL轉基因過表達株系。此外，通過原子吸收光譜法，整個atcl突變體幼苗中的總鈣含量高于野生型。使用轉基因水母發光蛋白和掃描離子選擇電極檢測到的atncl突變植物根尖細胞質中游離Ca2+和Ca2+通量的水平與野生型相比，在NaCl脅迫下需要更長的恢復時間。
所有這些數據表明，AtNCL編碼一個Na+ / Ca2+交換子樣蛋白，該蛋白參與擬南芥中Ca2+穩態的維持。 AtNCL可能代表高等植物中一種新型的Ca2+轉運蛋白。
C）Ca2+ flux in the roots was measured by SIET. The bath [Ca2+] was 0.1 mM. After approximately 5 min at the resting level, 50 mM NaCl was added. The Ca2+ flux was then measured for about 30 min in the root tips (shown in the inset). The number of samples is shown in parentheses.
期刊：Journal of Experimental Botany
主題：根尖和側根的無質子途徑有助于鎘在超級積葉景天中的過度積聚
標題：The apoplasmic pathway via the root apex and lateral roots contributes to Cd hyperaccumulation in the hyperaccumulator Sedum alfredii
影響因子：5.354
檢測指標：Cd2+流速
作者：浙江大學李廷強、陶琦
英文摘要
Although the significance of apoplasmic barriers in roots with regards to the uptake of toxic elements is generally known, the contribution of apoplasmic bypasses (ABs) to cadmium (Cd) hyperaccumulation is little understood.
Here, we employed a combination of stable isotopic tracer techniques, an ABs tracer, hydraulic measurements, suberin lamellae staining, metabolic inhibitors, and antitranspirants to investigate and quantify the impact of the ABs on translocation of Cd to the xylem in roots of a hyperaccumulating (H) ecotype and a non-hyperaccumulating (NH) ecotype of Sedum alfredii.
In the H ecotype, the Cd content in the xylem sap was proportional to hydrostatic pressure, which was attributed to pressure-driven flow via the ABs. The contribution of the ABs to Cd transportation to the xylem was dependent on the Cd concentration applied to the H ecotype (up to 37% at the highest concentration used). Cd-treated H ecotype roots showed significantly higher hydraulic conductance compared with the NH ecotype (76 vs 52 × 10–8 m s–1MPa–1), which is in accordance with less extensive suberization due to reduced expression of suberin-related genes.
The main entry sites of apoplasmically transported Cd were localized in the root apexes and lateral roots of the H ecotype, where suberin lamellae were not well developed. These findings highlight the significance of the apoplasmic bypass in Cd hyperaccumulation in hyperaccumulating ecotypes of S. alfredii.
中文摘要（谷歌機翻）
盡管人們普遍知道根部的質樸屏障對吸收有毒元素的重要性，但人們對質樸旁路（ABs）對鎘（Cd）超富集的貢獻卻知之甚少。
在這里，我們采用了穩定的同位素示蹤技術，ABs示蹤劑，水力測量，粉刺蛋白片狀染色，代謝抑制劑和止汗劑的組合，以研究和量化ABs對Cd向高積累根的木質素轉運至木質部的影響。 H）景天草的生態型和非高積累（NH）生態型。
在H型生態系統中，木質部汁液中的Cd含量與靜水壓力成正比，這歸因于通過AB的壓力驅動流。 AB對Cd向木質部運輸的貢獻取決于應用于H生態型的Cd濃度（使用濃度時高達37％）。與NH生態型相比，Cd處理的H生態型根系顯示出更高的水力傳導性（76 vs 52×10–8 m s–1MPa-1），這與由于suberin相關基因表達減少而引起的泛化作用減弱有關。
非質態運輸的鎘的主要進入部位位于H型生態系統的根尖和側根，那里的木栓質片狀細胞發育不佳。這些發現突顯了無性旁路在鎘超積累中對苜蓿鏈球菌超積累生態型的重要性。
(B) The mean Cd fluxes in root cells of the H and NH ecotypes of S. alfredii at different distances from the root apex. The data are means ±SE (n=3). Different letters indicate significant differences within one ecotype