沉积物镉污染下苦草与根际微生物群落响应特征  

RESPONSE CHARACTERISTICS OF VALLISNERIA NATANS AND RHIZOSPHERE MICROBIAL COMMUNITY UNDER SEDIMENT-CADMIUM POLLUTION

作　　者：余俊琪 徐一峰 郭瑶 刘相粉 李亚华 姚璐 王培 吴振斌[2] 周巧红[2] YU Jun-Qi;XU Yi-Feng;GUO Yao;LIU Xiang-Fen;LI Ya-Hua;YAO Lu;WANG Pei;WU Zhen-Bin;ZHOU Qiao-Hong(School of Resource&Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China;State Key Laboratory of Freshwater Ecology and Biotechnology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;University of Chinese Academy of Sciences,Beijing 100049,China;China University of Geosciences,Wuhan 430074,China)

机构地区：[1]武汉理工大学资源与环境工程学院,武汉430070 [2]中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,武汉430072 [3]中国科学院大学,北京100049 [4]中国地质大学,武汉430074

出　　处：《水生生物学报》2023年第11期1787-1797,共11页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(32173027);深圳科创委可持续发展专项(KCXFZ202002011006319)资助。

摘　　要：研究以典型沉水植物苦草(Vallisneria natans)为研究对象,通过在0、1、5、10、20和50 mg/kg沉积物镉(Cd)污染环境下苦草鲜重、株高和叶绿素(Chlorophyll)及丙二醛(Malondialdehyde,MDA)、超氧化物歧化酶(Superoxide Dismutase,SOD)和过氧化物酶(Peroxidase,POD)活性测定来分析苦草对镉的耐受效应,并借助生物/底泥富集因子(BSAF)和植物转运因子(TF)来了解苦草的富集能力,同时利用16S rRNA基因扩增子测序技术研究苦草根际细菌的群落结构对沉积物镉污染环境下的响应特征。结果表明:(1)当Cd≥20 mg/kg处理时,苦草植株鲜重、株高、叶绿素含量和抗逆能力下降,SOD和POD活性先上升后下降,MDA含量上升;(2)BSAF均超过1表明苦草能有效地富集污染底泥中的镉,转运系数(TF)均小于1,说明苦草依靠根滤机制来富集镉,建议在收获苦草时需要定期连根去除;(3)测序结果表明苦草根际由放线菌门、厚壁菌门和变形菌门等37个门细菌组成,包含鞘氨醇单胞菌属、黄杆菌属、马赛菌属、芽孢杆菌属和节杆菌属等植物促生细菌,这些细菌可能在促进苦草生长、耐受和富集重金属镉起到重要作用。研究分析了苦草在镉胁迫环境下形态学和生理生化等相关指标的变化和苦草根际细菌群落组成及其对镉胁迫的响应特征,为后续提高苦草修复效果提供了基础。In this study,the typical submerged macrophyte Vallisneria natans was selscted,and the fresh weight,plant height,chlorophyll,malondialdehyde(MDA),superoxide dismutase(SOD) and peroxidase(POD) activities of Vallisneria natans were measured at 0,1,5,10,20 and 50 mg/kg of sediment cadmium contamination to analyze the cadmium tolerance effect of Vallisneria natans,and the enrichment capacities were indicated by the values of Biota-sediment accumulation factor(BSAF) and translocation factor(TF),while the 16S rRNA gene amplicon sequencing technique was used to study the community structure of Vallisneria natans rhizosphere bacteria response to the sediment cadmium contamination.The results showed that:(1) When Cd≥20 mg/kg treatment,the fresh weight,plant height,chlorophyll content and the stress resistance decreased of Vallisneria natans.The activities of SOD and POD increased firstly and then reduced,MDA content increased with increasing concentration;(2) in all the treatments,BSAF exceeded 1,indicating that Vallisneria natans could effectively enrich cadmium in the contaminated sediment,and TF was less than 1,indicating that Vallisneria natans relied on root filtration mechanism to enrich cadmium,and needed to be harvested regularly;(3) the sequencing results showed that the rhizosphere bacteria of Vallisneria natans were mainly composed of 37 phylum,such as Actinobacteria,Firmicutes and Proteobacteria,including plant growth-promoting bacteria such as Sphingomonas,Flavisobacter,Massilia,Bacillus,and Arthrobacter,which may play important roles in promoting the growth,tolerance,and enrichment of cadmium in Vallisneria natans.In this study,we preliminarily analyzed the changes of morphological,physiological and biochemical indicators of Vallisneria natans under varied cadmium stress environments,and the composition of Vallisneria natans rhizosphere bacterial community and its response characteristics to cadmium stress,which provide guidance for the subsequent improvement of Vallisneria natans restoration efficiency.

关 键 词：沉积物 镉 富集能力 微生物群落 苦草 

分 类 号：Q178.1[生物学—水生生物学]