A novel non-invasive optical method for quantitative visualization of pH dynamics in the rhizosphere of plants
A novel non-invasive optical method for quantitative visualization of pH dynamics in the rhizosphere of plants
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DOI：
10.1111/j.1365-3040.2006.01616.x
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发表时间：
2007-02-01
影响因子：
7.3
通讯作者：
Gansert, Dirk
中科院分区：
文献类型：
--
作者：
Blossfeld, Stephan;Gansert, Dirk
介绍了一种新的光学方法，用于非侵入性的，定量的和高分辨率的空间和时间的pH值动态成像的植物根系介导的土壤。这种方法克服了目前的pH值测量的局限性，主要是短期和点状测量，通过记录长期动态的pH值在根-土界面的微观模式，而不干扰的生物和物理化学条件。灯心草，选择在永久淹没的根区中生根作为鉴定该技术的测试生物。测量结果表明，pH值的明显昼夜变化沿着的根，特别是沿着伸长区。由根系引起的pH日波动可达0.5个单位。在4秒的时间间隔超过8周的长期记录显示相当大的空间和时间模式的pH值动态在根际约10%的pH值规模（pH 7.0-8.5）。通过使用pH电极对测量数据进行验证。同时测得的氧浓度显示周围的根尖缺氧条件（10-70 μ mol O-2 L-1）和几乎缺氧条件（0.9 μ mol O-2 L-1）在散装土壤。本研究资格这种新的pH传感技术作为一个强大的分析工具，定量可视化的不受干扰的生物过程动态。
A novel optical method for non-invasive, quantitative and high-resolution imaging of spatial and temporal pH dynamics in soils mediated by plant roots is introduced. This method overcomes present limitations of measurement of pH, mainly short-term and punctiform measurements, by recording long-term dynamics of the micro-pattern of pH in the root-soil interface without disturbance of the biological and physico-chemical conditions. Juncus effusus L., rooting in a permanently flooded rhizotron, was selected as the test organism for qualifying the technique. The measurements showed pronounced diurnal variations of pH along the roots, particularly along the elongation zone. Diurnal oscillation of pH caused by the roots reached up to 0.5 units. Long-term records at 4 s intervals over more than 8 weeks revealed considerable spatial and temporal patterns of pH dynamics in the rhizosphere of about 10% of the pH scale (pH 7.0-8.5). The measured data were validated by the use of pH electrodes. Concomitantly measured oxygen concentration showed hypoxic conditions around root tips (10-70 mu mol O-2 L-1) and almost anoxic conditions (0.9 mu mol O-2 L-1) in the bulk soil. The present study qualifies this novel pH-sensing technique as a powerful analytical tool for quantitative visualization of undisturbed bioprocess dynamics.