Department of Food Technology, Şebinkarahisar School of Applied Sciences, Giresun University, Giresun, Turkey.
Faculty of Science and Art, Department of Biology, Giresun University, Giresun, Turkey.
Sci Rep. 2023 Mar 25;13(1):4888. doi: 10.1038/s41598-023-32183-6.
The excessive use of metaldehyde in agriculture to combat mollusks endangers both the environment and non-target organisms. The aim of this study is to investigate the toxicity caused by metaldehyde in Allium cepa with the help of physiological, cytogenetic, biochemical and anatomical parameters. Also, DNA fragmentation caused by metaldehyde in root tip cells was measured by the "Comet Assay" method. The control group was germinated with tap water and the application groups were germinated with 20 mg/L metaldehyde, 40 mg/L metaldehyde, 100 mg/L metaldehyde and 200 mg/L metaldehyde for 72 h. The results of the physiological parameters showed that metaldehyde had a growth-limiting effect in A. cepa, depending on the application dose. According to root elongation levels, the EC (effective concentration) value for metaldehyde was 60.6 mg/L in A. cepa. As the treatment dose increased, the incidence of micronucleus and chromosomal aberrations gradually increased while mitotic index decreased. Metaldehyde exposure induced damages such as sticky chromosome, fragment, unequal distribution of chromatin, reverse polarization, bridge, and multipolar anaphase. In addition, metaldehyde caused cell damage in epidermis and cortex, thickening of the cortex cell wall and flattened cell nucleus in root meristem. Increasing doses of metaldehyde application also increased malondialdehyde levels, superoxide dismutase and catalase activities. As a result, it has been determined that the toxicity of metaldehyde in plants is versatile and the A. cepa test material is a suitable biological indicator to determine this toxicity.
在农业中过度使用多聚甲醛来防治软体动物会危害环境和非目标生物。本研究旨在借助生理、细胞遗传学、生化和解剖学参数来研究多聚甲醛对洋葱（Allium cepa）造成的毒性。此外，还通过“彗星试验”方法测量了多聚甲醛在根尖细胞中引起的 DNA 片段化。对照组用自来水发芽，实验组分别用 20mg/L、40mg/L、100mg/L 和 200mg/L 的多聚甲醛处理 72 小时。生理参数的结果表明，多聚甲醛对洋葱的生长有抑制作用，其抑制效果取决于应用剂量。根据根伸长水平，多聚甲醛对洋葱的 EC（有效浓度）值为 60.6mg/L。随着处理剂量的增加，微核和染色体畸变的发生率逐渐增加，而有丝分裂指数降低。多聚甲醛暴露会导致粘性染色体、染色体片段、染色质不均匀分布、反向极化、桥和多极后期等损伤。此外，多聚甲醛还会引起表皮和皮层细胞的损伤，根分生组织中皮层细胞壁变厚，细胞核扁平化。多聚甲醛应用剂量的增加也会导致丙二醛水平、超氧化物歧化酶和过氧化氢酶活性的增加。因此，确定了多聚甲醛对植物的毒性是多方面的，洋葱试验材料是确定这种毒性的合适生物指示剂。
