Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany.
Bayer AG, Alfred-Nobel-Straße 50, 40789 Monheim am Rhein, Germany.
Chemosphere. 2019 Mar;218:36-41. doi: 10.1016/j.chemosphere.2018.11.069. Epub 2018 Nov 12.
Knowledge about translocation of plant protection products (PPP's) in plants is important to understand the uptake via the root system. Here we report the combination of analysis of tissue extracts by LC-HRMS, autoradiography of C-labeled compounds and MALDI-MSI, which combine qualitative and quantitative information of chemical composition and the spatial distribution of PPP's and their metabolites in situ. Therefore, the uptake of the phenylamide fungicide metalaxyl was studied in tomato plants (Solanum lycopersicum) using a hydroponic system. The plants have been cultivated in perlite until the two-leaf stage and were transferred into the hydroponic test system afterwards. The radioactive labeled fungicide was readily taken up by the roots during the normal water consumption and radioactivity was translocated uniformly to the aboveground part of the tomato plants, while only small proportion of the applied radioactivity were observed in the roots. The distribution of metalaxyl after the plant uptake experiment in the primary roots where analyzed by a transversal tissue section in the zone of maturation. Metalaxyl is mainly localized in root xylem and in cortex located at the epidermis. With LC-HRMS and radiochemical analyses of stem and leaf, no parent compound was detectable. Four polar metabolites were the main identified components of the residue and could be visualized by MALDI-imaging mass spectrometry. With these results we could show, that the fungicide metalaxyl is taken up by the plant via the roots during the regular water consumption and transported to xylem.
了解植物保护产品（PPP）在植物中的迁移对于理解通过根系吸收至关重要。在这里，我们报告了通过 LC-HRMS 分析组织提取物、C 标记化合物的放射自显影和 MALDI-MSI 的组合，这些方法结合了 PPP 及其代谢物的化学组成和空间分布的定性和定量信息。因此，我们使用水培系统研究了苯酰胺类杀菌剂金属灵在番茄植物（Solanum lycopersicum）中的吸收情况。这些植物在珍珠岩中培育，直到出现两片子叶，然后再转移到水培测试系统中。在正常的水分消耗过程中，放射性标记的杀菌剂很容易被根系吸收，放射性物质均匀地转移到番茄植物的地上部分，而只有一小部分应用的放射性物质被观察到在根部。通过在成熟区对主根进行横向组织切片分析，研究了植物吸收实验后金属灵的分布情况。金属灵主要定位于根木质部和位于表皮的皮层。通过 LC-HRMS 和对茎和叶的放射性化学分析，未检测到母体化合物。四种极性代谢物是残基的主要鉴定成分，可以通过 MALDI-成像质谱进行可视化。通过这些结果，我们可以表明，杀菌剂金属灵通过植物的根系在正常的水分消耗过程中被吸收，并被运输到木质部。
