New Methods for Testing/Determining the Environmental Exposure to Glyphosate in Sunflower (Helianthus annuus L.) Plants

Abstract

Glyphosate is still the subject of much debate, as several studies report its effects on the environment. Sunflower (GK Milia CL) was set up as an experimental plant and treated with glyphosate concentrations of 500 ppm and 1000 ppm in two treatments. Glyphosate was found to be absorbed from the soil into the plant organism through the roots, which was also detectable in the leaf and root. Glyphosate was also significantly detected in the plant 5 weeks after treatment and in plants that did not receive glyphosate treatment directly, so it could be taken up through the soil. Based on the morphological results, treatment with higher concentrations (1000 ppm) of glyphosate increased the dried mass and resulted in shorter, thicker roots. Histological results also showed that basal and transporter tissue distortions were observed in the glyphosate-treated plants compared to the control group. Cells were distorted with increasing concentration, vacuoles formed, and the cell wall was weakened in both the leaf-treated and inter-row-treated groups. In the future, it will be worth exploring alternative agricultural technologies that can reduce the risk of glyphosate while increasing economic outcomes. This may make the use of glyphosate more environmentally conscious.

Morphological, Histological, and Glyphosate Residue Analysis of Helianthus annuus L. Plants Treated with Glyphosate

“…Cultivation in a container is of particular importance, taking into account environmental protection aspects (spraying on open ground can enter the ecosphere). At that time, the plants were 5 weeks old, as in our previous experiment in 2021 [32]. Two weeks passed between the glyphosate treatment and the final assessment.…”

“…The literature data show that glyphosate and its metabolites are hazardous to the environment and can be detected not only in the target plant but also in the surrounding plants, so there is a high chance that toxic substances will enter the food chain with the use of glyphosate. In our glyphosate tests with sunflowers [32], which began in 2021, we established that glyphosate could appear in the target plants even if the target plants were not treated with the chemical directly. We continue these studies with a variety of the H. annuus species, as this species is an important crop not only in the food industry, but also in the field of ornamental plant application.…”

“…The seeds have not been pretreated or coated. The variety was also used successfully in previous tests with glyphosate exposure, the variety is susceptible to the active ingredient [32], but several literature references point to the sensitivity of H. annuus to glyphosate [36][37][38][39][40].…”

“…The instrumental analytical method published earlier [32] was used for the measurements, with some modifications. A total of 10 mL of acetonitrile was added to 1 g of dried sample in a 50 mL centrifuge tube.…”

“…Derivatization of the compounds was carried out according to the earlier published procedure [32]. Briefly, 60 µL of dry pyridine was added to the dried residue, and after 5 min 100 µL of silylating agent, N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) containing 1% trimethylchlorosilane (TMCS) was added.…”