Uptake of aluminium into Arabidopsis root cells measured by fluorescent lifetime imaging
Uptake of aluminium into Arabidopsis root cells measured by fluorescent lifetime imaging
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DOI：
10.1093/aob/mcp098
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发表时间：
2009-07-01
期刊：
影响因子：
4.2
通讯作者：
Rengel, Zed
中科院分区：
文献类型：
--
作者：
Babourina, Olga;Rengel, Zed
测定完整根细胞质膜对Al（3+）的吸收速率对于了解植物铝毒的作用机制和时间进程至关重要。本研究采用荧光寿命成像（FLIM）技术定量研究了植物根细胞胞质中Al（3+）的吸收，并与传统的荧光寿命成像方法进行了比较。通过测定拟南芥幼苗在酸性和Al（3+）胁迫下的荧光寿命和细胞内pH值，研究了Al-光镓{5-氯-3-[（2，4-二羟基苯基）偶氮]-2-羟基苯磺酸}配合物的荧光寿命。Al（3+）进入的主要部位是分生组织和远端伸长区，而通过成熟根区的皮层和表皮吸收Al（3+）是有限的。在100 μ mAlCl（3）（pH 4，中心点2）中暴露30分钟后，观察到Al进入细胞质的最大吸收速率（分生根区为2-3 μ mol m（-3）min（-1），成熟区为3-7 μ mol m（-3）min（-1））。在100 μ mAlCl（3）处理的最初3小时内，细胞内Al浓度增加到0中心点4 μ mAl（3）。在Al（3+）胁迫的初始阶段，Al-荧光镓配合物荧光的FLIM分析可用于可靠地定量完整根细胞细胞质中Al的吸收。
Measuring the Al(3+) uptake rate across the plasma membrane of intact root cells is crucial for understanding the mechanisms and time-course of Al toxicity in plants. However, a reliable method with the sufficient spatial and temporal resolution to estimate Al(3+) uptake in intact root cells does not exist.In the current study, fluorescent lifetime imaging (FLIM) analysis was used to quantify Al(3+) uptake in the root-cell cytoplasm in vivo. This was performed via the estimation of the fluorescence lifetime of Al-lumogallion {5-chloro-3[(2,4-dihydroxyphenyl)azo]-2-hydroxybenzenesulfonic acid} complexes and measurements of intracellular pH while exposing arabidopsis seedlings to acidic and Al(3+) stresses.The lifetime of Al-lumogallion complexes fluorescence is pH-dependent. The primary sites for Al(3+) entry are the meristem and distal elongation zones, while Al(3+) uptake via the cortex and epidermis of the mature root zone is limited. The maximum rates of Al uptake into the cytoplasm (2-3 mu mol m(-3) min(-1) for the meristematic root zone and 3-7 mu mol m(-3) min(-1) for the mature zone) were observed after a 30-min exposure to 100 mu m AlCl(3) (pH 4 center dot 2). Intracellular Al concentration increased to 0 center dot 4 mu mAl within the first 3 h of exposure to 100 mu m AlCl(3).FLIM analysis of the fluorescence of Al-lumogallion complexes can be used to reliably quantify Al uptake in the cytoplasm of intact root cells at the initial stages of Al(3+) stress.