Yılmaz Hüseyin, Yalçın Emine, Çavuşoğlu Kültiğin
Department of Biology, Faculty of Science and Art, Giresun University, 28200, Giresun, Turkey.
Sci Rep. 2025 Sep 26;15(1):33263. doi: 10.1038/s41598-025-18861-7.
In this study, the toxicological effects of elevated concentrations of iron (FeSO), an essential trace element, were systematically investigated in Allium cepa L. A comprehensive set of biomarkers were employed, encompassing cytogenetic parameters (mitotic index, micronucleus frequency, chromosomal aberrations), physiological indicators (germination rate, root length, biomass accumulation), biochemical markers (malondialdehyde, proline content, chlorophyll concentration, superoxide dismutase and catalase activities), and anatomical assessments of root meristem cell integrity. Additionally, the Comet assay was utilized to quantify DNA damage. Four experimental groups were established: one control group and three treatment groups, each exposed to FeSO concentrations of 50, 100, and 200 mg/L, respectively. At the conclusion of the experimental period, root tips and leaf tissues were collected and processed using standardized protocols for subsequent analyses. The results demonstrated that the control group exhibited superior physiological performance, with the highest values recorded for germination, root elongation, MI percentage and chlorophyll content. Conversely, FeSO treatments induced a concentration-dependent decline in these parameters, accompanied by a significant increase in MN frequency, chromosomal aberrations, MDA and proline levels, and SOD and CAT enzyme activities. The most pronounced effects were observed at 200 mg/L FeSO where the MI was reduced by 36% and the DNA tail percentage-a marker of DNA fragmentation-elevated by 57.3% compared to the control. Additionally, FeSO exposure induced dose-dependent anatomical damage in A. cepa root meristem cells, particularly causing epidermis and cortex cell damage, nucleus flattening, and conduction tissue thickening, likely due to oxidative stress and mechanical pressure. These findings reveal that excessive FeSO exposure triggers severe genotoxic, biochemical, and anatomical disruptions in Allium cepa, driven by oxidative stress and cellular damage. This underscores the potential ecological risks of iron pollution in terrestrial and aquatic environments.
在本研究中，对重要微量元素铁（硫酸亚铁）浓度升高的毒理学效应在洋葱中进行了系统研究。采用了一套全面的生物标志物，包括细胞遗传学参数（有丝分裂指数、微核频率、染色体畸变）、生理指标（发芽率、根长、生物量积累）、生化标志物（丙二醛、脯氨酸含量、叶绿素浓度、超氧化物歧化酶和过氧化氢酶活性）以及对根分生组织细胞完整性的解剖学评估。此外，采用彗星试验来量化DNA损伤。设立了四个实验组：一个对照组和三个处理组，分别暴露于50、100和200mg/L的硫酸亚铁浓度下。在实验期结束时，收集根尖和叶片组织，并按照标准化方案进行处理，以进行后续分析。结果表明，对照组表现出更好的生理性能，发芽、根伸长、有丝分裂指数百分比和叶绿素含量均记录到最高值。相反，硫酸亚铁处理导致这些参数呈浓度依赖性下降，同时微核频率、染色体畸变、丙二醛和脯氨酸水平以及超氧化物歧化酶和过氧化氢酶活性显著增加。在200mg/L硫酸亚铁处理下观察到最明显的影响，与对照组相比，有丝分裂指数降低了36%，DNA尾部百分比（DNA片段化的标志物）升高了57.3%。此外，硫酸亚铁暴露诱导洋葱根分生组织细胞出现剂量依赖性的解剖学损伤，特别是导致表皮和皮层细胞损伤、细胞核扁平以及传导组织增厚，这可能是由于氧化应激和机械压力所致。这些发现表明，过量的硫酸亚铁暴露会在洋葱中引发严重的遗传毒性、生化和解剖学破坏，其驱动因素是氧化应激和细胞损伤。这突出了陆地和水生环境中铁污染的潜在生态风险。
