Uptake, translocation and transformation of arsenate and arsenite in sunflower (Helianthus annuus):: formation of arsenic-phytochelatin complexes during exposure to high arsenic concentrations
Uptake, translocation and transformation of arsenate and arsenite in sunflower (Helianthus annuus):: formation of arsenic-phytochelatin complexes during exposure to high arsenic concentrations
复制标题
DOI：
10.1111/j.1469-8137.2005.01519.x
复制
发表时间：
2005-12-01
期刊：
影响因子：
9.4
通讯作者：
Feldmann, J
中科院分区：
文献类型：
--
作者：
Raab, A;Schat, H;Feldmann, J
本研究的目的是确定砷-植物螯合素（As-PC）复合物在砷不耐受植物的根、茎和叶中形成的时间依赖性（向日葵）在暴露于66 mol l（-1）砷（As-（III））或砷酸盐（As-（V））的过程中。（电感耦合等离子体质谱，ICP-MS）和分子特异性（电喷雾电离质谱，ES-MS）检测系统与合适的色谱柱和洗脱条件相结合，使我们能够直接鉴定和定量As-PC复合物。annuus含有多达14种不同的砷物种，包括亚砷酸盐与两个（γ-Glu-Cys）（2）-Gly分子的复合物[As-（III）-（PC 2）（2）]，新鉴定的单甲基胂植物螯合素-2或曰（γ-Glu-Cys）（2）-Gly CH 3As（MA（（III））-PC 2）和至少8种尚未鉴定的物种。砷与（γ-Glu-Cys）（3）-Gly的复合物（As-（III）-PC_3）和砷与谷胱甘肽（GSH）和（γ-Glu-Cys）（2）-Gly的复合物（GS-As-（III）-PC_2）存在于所有砷暴露植物的根、茎和叶中。GS-As-（III）-PC 2复合物是暴露1 h后的主要复合物。As-（III）-PC_3在3 h后成为主要的As-PC复合物，可结合40%的As，而根、茎和叶中没有发现As-PC复合物，表明As-PC复合物不参与As从根向叶的转运.一年生的
The aim of the study was to determine the time-dependent formation of arsenic-phytochelatin (As-PC) complexes in the roots, stems and leaves of an arsenic-nontolerant plant (Helianthus annuus) during exposure to 66 mol l(-1) arsenite (As-(III)) or arsenate (As-(V)).We used our previously developed method of simultaneous element-specific (inductively coupled plasma mass spectrometry, ICP-MS) and molecular-specific (electrospray-ionization mass spectrometry, ES-MS) detection systems interfaced with a suitable chromatographic column and eluent conditions, which enabled us to identify and quantify As-PC complexes directly.Roots of As-exposed H. annuus contained up to 14 different arsenic species, including the complex of arsenite with two (gamma-Glu-Cys)(2)-Gly molecules [As-(III)-(PC2)(2)], the newly identified monomethylarsonic phytochelatin-2 or (gamma-Glu-Cys)(2)-Gly CH3As (MA((III))-PC2) and at least eight not yet identified species. The complex of arsenite with (gamma-Glu-Cys)(3)-Gly (As-(III)-PC3) and the complex of arsenite with glutathione (GSH) and (gamma-Glu-Cys)(2)-Gly (GS-As-(III)-PC2) were present in all samples (roots, stems and leaves) taken from plants exposed to As. The GS-As-(III)-PC2 complex was the dominant complex after 1 h of exposure. As-(III)-PC3 became the predominant As-PC complex after 3 h, binding up to 40% of the As present in the exposed plants.No As-PC complexes were found in sap (mainly xylem sap from the root system), in contrast to roots, stems and leaves, which is unequivocal evidence that As-PC complexes are not involved in the translocation of As from root to leaves of H. annuus.