Hysteresis of heavy metals uptake induced in Taraxacum officinale by thiuram

Abstract

Dandelion (Taraxacum officinale) yields active substances frequently used in herbal medicinal preparations. Its plantations are exposed to fungal plagues which pose a threat to herbal crops. The aim of this study was to evaluate the long time effects of a fungicide thiuram on dandelion growth and photosynthesis. Additionally, the manganese, iron, copper, zinc, cadmium, and lead uptake and transport were also investigated. Plants were cultivated under greenhouse conditions by the pot method in a universal flowering soil. The elements content in soil and plants were determined by the HR-CS FAAS spectrometer. Thiuram concentrations were established by the HPLC. Those analyses showed that almost 80% of thiuram decomposed within two weeks of its application. The photosynthesis indicators suggested, that plants were in good conditions and the fungicide supplementation facilitated plant growth. The latter could be prompted by thiuram acting as a sulfur rich chemical micro fertilizer. The hypothesis, that thiuram significantly affects heavy metals interactions in dandelion was proved by the one-way analysis of variance. Notable, metals uptake did not completely recover after fungicide decomposition for all investigated elements except iron We suggest to define this chemically induced, time-dependent heavy metals migrations in the soil–plant system as hysteresis of heavy metals uptake.

The Impact of Soil pH on Heavy Metals Uptake and Photosynthesis Efficiency in Melissa officinalis, Taraxacum officinalis, Ocimum basilicum

“…The copper uptake was prompted by acidic conditions in basil and almost neutral environment (pH = 6.0) in dandelion and lemon balm. Notably, migration of metals from roots to shoots as defined by respective translocation factors [ 32 ] is quite pH-independent. Soil pH has very limited influence on metals transfer within the plant tissues as indicated by the TF values.…”

Quantitative Analysis of Fungal Contamination of Different Herbal Medicines in China

“…Although other herbs such as Pseudostellaria heterophylla and Glycyrrhiza uralensis were also severely contaminated with fungi, Taraxacum mongolicum was the only herb detected with large amounts of both Fusarium and Alternaria. Although Taraxacum mongolicum is commonly used in China, few studies have investigated its safety, and few studies have focused on its heavy metal residues [28][29][30]. A comprehensive analysis of chemical and biological pollutants in Taraxacum mongolicum was performed in Poland, and 14 pathogenic fungi were found by PCR [31].…”