Journal of Hazardous Materials ( IF 12.2 ) Pub Date : 2021-02-12 , DOI: 10.1016/j.jhazmat.2021.125390
Jinglong Li , Baodong Chen , Xin Zhang , Zhipeng Hao , Xuemeng Zhang , Yongguan Zhu
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It is well known that arbuscular mycorrhizal (AM) fungi can enhance plant arsenic (As) resistance by influencing As uptake, translocation, and speciation; however, As transformation and volatilization by an entire plant inoculated with AM fungus remains uninvestigated. In the present study, AM symbiosis of Rhizophagus irregularis with unbroken Medicago sativa was successfully established in vitro. Afterwards, five concentrations of arsenate were applied to the culture media. The results showed that AM inoculation could methylate inorganic As into dimethylarsinic acid (DMA), dimethylarsine (DMAsH), and trimethylarsine (TMAs), which were detected in the plants, media, or air. Volatile As, accounting for a small proportion of total organic As, appeared under high arsenate exposure, accompanied by remarkable upregulation of root RiMT-11, an arsenite methyltransferase gene in R. irregularis. In addition, AM colonization significantly increased arsenite percentages in plant tissues and external media. Regardless of As species, AM inoculation tended to release the transformed As into the environment rather than transfer them to plant tissues. Our present study, for the first time, comprehensively verified As methylation, volatilization, and reduction by AM fungus associated with the entire plant under absolute axenic conditions and gained a deeper insight into As metabolism in AM symbionts.
中文翻译:
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砷环境下丛枝菌根共生引起的砷转化和挥发
众所周知,丛枝菌根(AM)真菌可通过影响砷的吸收,转运和形成,从而增强植物对砷(As)的抗性。然而,由于整株接种AM真菌的植物的转化和挥发尚未得到研究。在本研究中,AM共生Rhizophagus irregularis与不间断的紫花苜蓿在体外成功建立。之后,将五浓度的砷酸盐施加到培养基上。结果表明,AM接种可以将无机As甲基化为二甲基inorganic酸(DMA),二甲基ar(DMAsH)和三甲基ar(TMA),这些都是在植物,培养基或空气中检测到的。挥发性砷占有机砷总量的一小部分,在高砷暴露下会出现,并伴有不规则红斑病菌根部甲基转移酶基因RiMT-11的显着上调。。另外,AM定植显着增加了植物组织和外部培养基中亚砷酸盐的百分比。无论是哪种As物种,AM接种都倾向于将转化的As释放到环境中,而不是将其转移到植物组织中。我们的本研究首次全面验证了在绝对焦虑环境下与整个植物相关联的AM真菌的甲基化,挥发和还原,并获得了对AM共生体中As代谢的更深入的了解。