Abstract This study revealed the cytotoxicity, genotoxicity and toxicity mechanism of uranium (U) in plants. The cytotoxic effect of U was evaluated by detecting the survival status of root border cells; the genotoxic effect was evaluated by micronuclear experiments; and the toxicity mechanism of U to plants was primarily revealed by combining with transcriptome. Results showed that after U exposure, the proportion of late apoptotic cells and dead cells was significantly higher than the control, indicating that U could induce the apoptosis or necrosis of root border cells. The micronucleus rate increased dramatically after U exposure, reaching a maximum of 4.89 times the control, whereas the mitotic index decreased significantly, reaching a minimum of 26.00% of the control. Moreover, the activities of superoxide dismutase and peroxidase decreased, triggering severe oxidative stress. Combined with the transcriptome data, this study showed that U interfered with the expression of genes related to antioxidant enzymes, the cell cycle and the DNA repair system. In conclusion, U strongly terminated the root border cells and blocked the mitosis, therefore inhibiting the growth of the Vicia faba root. It also caused DNA damage by interfering with the antioxidant enzymes to trigger oxidative stress and prevented DNA self-repair by interfering with the DNA repair system.

中文翻译：

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蚕豆根中铀的细胞毒性和遗传毒性评价及毒理机制

摘要 本研究揭示了铀（U）对植物的细胞毒性、遗传毒性和毒性机制。通过检测根缘细胞的存活状态来评价U的细胞毒作用；通过微核实验评价遗传毒性作用；主要通过结合转录组揭示U对植物的毒性机制。结果表明，U暴露后，晚期凋亡细胞和死亡细胞的比例显着高于对照，表明U可以诱导根缘细胞凋亡或坏死。U暴露后微核率显着增加，最高达到对照的4.89倍，而有丝分裂指数显着下降，最低达到对照的26.00%。此外，超氧化物歧化酶和过氧化物酶的活性降低，引发严重的氧化应激。结合转录组数据，本研究表明U干扰了抗氧化酶、细胞周期和DNA修复系统相关基因的表达。总之，U强烈终止了根缘细胞并阻止了有丝分裂，从而抑制了蚕豆根的生长。它还通过干扰抗氧化酶引发氧化应激而引起 DNA 损伤，并通过干扰 DNA 修复系统阻止 DNA 自我修复。因此抑制蚕豆根的生长。它还通过干扰抗氧化酶引发氧化应激而引起 DNA 损伤，并通过干扰 DNA 修复系统阻止 DNA 自我修复。因此抑制蚕豆根的生长。它还通过干扰抗氧化酶引发氧化应激而引起 DNA 损伤，并通过干扰 DNA 修复系统阻止 DNA 自我修复。