The Effects of Picloram and Clopyralid on Ocimum Basilicum (Basil)—A Study of the Uptake, Distribution and Translocation of Synthetic Auxins from Soil to Plant

The current study monitored the degree of uptake, distribution, bioaccumulation, and translocation of synthetic auxins (Picloram and Clopyralid) in medicinal plants (Basil). The study’s main objectives were the development and optimization of an analytical method for the identification and quantification of auxins, an optimized method of auxins extraction from soil and plant samples, and, based on the analytical results obtained, the evaluation of bioaccumulation and translocation capacity. To evaluate the effects produced by synthetic auxins on the Basil plant, three experiments were carried out in parallel (Basil-Clopyralid, Basil-Picloram, and Basil-Clopyralid-Picloram) for 15 days, where the plant was permanently exposed to a constant concentration of auxins. The study results showed that in the individual tests and the test carried out in the mixture, the highest concentration was recorded for Clopyralid in the Basil leaves, 16 µg/kg d.w., respectively, 22 µg/kg d.w. The antagonist, Picloram, was primarily detected in the plant’s roots, up to 7.2 µg/kg d.w. Therefore, Picloram favors the accumulation of Clopyralid in high percentages in all plant organs. The bioconcentration factors (BCF) and translocation factors (TF) calculation showed values lower than 1, indicating that Basil is an excluder and has no potential for phytoremediation.