Influence of cadmium and microplastics on physiological responses, ultrastructure and rhizosphere microbial community of duckweed.
Influence of cadmium and microplastics on physiological responses, ultrastructure and rhizosphere microbial community of duckweed.
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镉和微塑料对浮萍生理响应、超微结构及根际微生物群落的影响。
DOI：
10.1016/j.ecoenv.2022.114011
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发表时间：
2022-08
影响因子：
6.8
通讯作者：
Gui-Li Yang;M. Zheng;Haimin Liao;Ai-Juan Tan;Dan Feng;Shiming Lv
中科院分区：
文献类型：
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作者：
Gui-Li Yang;M. Zheng;Haimin Liao;Ai-Juan Tan;Dan Feng;Shiming Lv
重金属和微塑料的复合污染在淡水环境中很普遍。但是，关于它们对水生植物的联合作用的研究却很少。研究了0.01 mg L-1镉（Cd）、50 mg L-1聚乙烯和50 mg L-1聚丙烯单独和复合胁迫15 d对浮萍生理响应、超微结构和根际微生物群落的影响。结果表明，Cd和塑料微粒单独或复合胁迫抑制了浮萍的生长，使根长缩短，叶绿素含量降低。与单一Cd处理相比，微塑料与Cd复合胁迫提高了浮萍的生长速率，提高了超氧化物歧化酶活性和丙二醛含量，减轻了叶绿体结构损伤，表明复合胁迫可以减轻重金属对浮萍的毒害。通过对浮萍根际微生物多样性的研究，共鉴定出1381个操作分类单位（OTU），并在浮萍根际检测到丰富的微生物群落。其中，主要的微生物群落为变形菌门、拟杆菌门和蓝藻门。与Cd单一胁迫相比，复合胁迫下根际微生物群落的ACE和Chao指数均有所增加，表明复合胁迫处理后微生物群落的多样性和丰富度得到提高。本研究揭示了重金属和微塑料对水生植物的影响，为浮萍在复杂水体污染中的应用提供了理论依据。
The combined contamination of heavy metals and microplastics is widespread in freshwater environments. However, there are few researches on their combined effects on aquatic plants. In this study, the effects of single and combined stress of 0.01 mg L-1cadmium (Cd), 50 mg L-1polyethylene and 50 mg L-1polypropylene for 15 days on the physiological response, ultrastructure and rhizosphere microbial community of duckweed were investigated. The results showed that Cd and microplastics single or combined stress inhibited the growth of duckweed, shortened the root length and decreased the chlorophyll content. Compared with single Cd treatments, the combination of microplastics and Cd increased duckweed growth rate and increased superoxide dismutase activity and malondialdehyde content and reduced chloroplast structural damage, indicating that the combined stress could reduce the toxicity of heavy metals to duckweed. Through the study of rhizosphere microbial diversity, 1381 Operational Taxonomic Unit (OTUs) were identified and rich microbial communities were detected in the duckweed rhizosphere. Among them, the main microbial communities wereProteobacteria,Bacteroidetes, andCyanobacteria. Compared with Cd single stress, the ACE and chao index of rhizosphere microbial community increased under combined stress, indicating that the diversity and abundance of microbial communities were improved after combined stress treatment. Our study revealed the effects of heavy metals and microplastics on aquatic plants, providing a theoretical basis for duckweed applications in complex water pollution.