Pesticide uptake and translocation in plants monitored in situ via laser ablation dielectric barrier discharge ionization mass spectrometry imaging
Xue You, Qiao Lu, Xiaokang Guan, Zhouyi Xu, Renato Zenobi
Abstract
For reducing pesticide usage and enhancing the effectiveness of pest control, it is necessary to elucidate the mechanisms of pesticide uptake and translocation in plants. Here, atmospheric pressure laser ablation dielectric barrier discharge ionization mass spectrometry imaging (LA-DBDI-MSI) was used to for in-situ monitoring of pesticide uptake and translocation in plants with a spatial resolution of 25 μm, and only requiring minimal or no sample preparation. Roots and leaves of tomato plants that had been exposed to a systemic pesticide, difenoconazole, were studied. From MSI data of tomato leaves, we found that difenoconazole was mainly distributed in the leaf veins after 6 days of pesticide exposure, but distributed throughout the leaf after 10 days of pesticide exposure. Endogenous substances are mainly distributed in the mesophyll, but are not present in the veins. This study clarifies the uptake and translocation mechanism of pesticides in plants, which is of great significance for reducing the dosage of pesticides and improving the effect of plant disease control.