摘要
目前根际微生物协同重金属超富集植物修复重金属污染土壤具有较大应用潜力.从电解锰渣历史遗留污染场地中筛选得到了1株具有产铁载体和IAA能力的细菌,经16S rDNA鉴定为沙雷氏菌(Serratia marcescens A-4),将其接种至含有Mn^(2+)的选择性LB培养基中,发现其在高达20000 mg/L的Mn^(2+)选择性培养基中可以正常生长.接着,将该沙雷氏菌A-4接种于种植超富集植物鸭跖草(Commelina communis)的种植基质中,基质设置LM、MM和MM三类处理组,其中电解锰渣质量占比分别为15%、30%和50%,探究沙雷氏菌A-4对鸭跖草植株的生长状况、锰富集能力和根际微生物群落结构的影响.研究结果表明,与空白对照组相比较,LM、MM和HM处理组接种沙雷氏菌A-4后,鸭跖草生物量分别提高15.7%、39.6%和70.2%,植物地上部分锰富集能力显著增加,锰元素含量分别提高1.62倍(P<0.05)、1.68倍(P<0.05)和1.07倍,转运系数分别从8.73±2.77、8.93±1.55和6.17±1.17提高至14.15±0.70(P<0.05)、26.73±0.10(P<0.05)和31.04±16.47(P<0.05).另外,Shannon指数显示,MM和HM处理组之间存在微生物群落多样性显著差异,PCoA表明各处理组间存在较明显的聚类差异.微生物群落分析结果显示,菌株A-4的施加对鸭跖草根际周围关键菌丰度造成明显影响,表现为Abditibacteriota、Gemmatimonadetes相对丰度的增加和Parcubacteria相对丰度的减少.KEGG功能基因丰度分析结果显示,调控谷胱甘肽转移酶和铁复合物外膜受体蛋白功能基因丰度在LM和MM处理组中显著提高,这些功能基因可能是影响鸭跖草生长和吸收锰的关键基因.本研究表明接种具有产铁载体和IAA能力的A-4对鸭跖草生长、锰吸收、根际微生物群落和功能基因均有显著调节作用,可为揭示微生物强化植物生长及锰吸收的机制和超富集植物-微生物联合修复锰污染土壤的相关研究提供理论参考.(图7表4参48)
The synergistic effect of rhizosphere microorganisms on heavy metal hyperaccumulation in plant remediation of contaminated soils has significant potential for application.We identified a strain of bacteria with the ability to produce siderophores and indole-3-acetic acid(IAA)from a historically contaminated site of electrolytic manganese slag.Based on 16S rDNA analysis,the isolate was identified as Serratia marcescens A-4.This strain was able to grow on a selective LB medium containing Mn2+concentrations up to 20000 mg/L.The strain A-4 was inoculated into the substrate of the hyperaccumulator Commelina communis,with substrates treated with low,medium,and high manganese(LM,MM,HM)groups,where electrolytic Mn residues accounted for 15%,30%,and 50%,respectively.The study investigated the effects of A-4 on the growth,Mn accumulation,and rhizosphere microbial community of C.communis.Results showed that,compared to the blank control groups,the LM,MM,and HM groups inoculated with A-4 increased the biomass of C.communis by 15.7%,39.6%,and 70.2%,respectively.The manganese enrichment ability of the aboveground parts of C.communis increased significantly,with Mn concentration rising by 1.62 times(P<0.05),1.68 times(P<0.05),and 1.07 times,respectively.The transport factors of the experimental groups increased from 8.73±2.77,8.93±1.55,and 6.17±1.17 to 14.15±0.70(P<0.05),26.73±0.10(P<0.05),and 31.04±16.47(P<0.05),respectively.Additionally,the Shannon index revealed significant differences in microbial community diversity between the MM and HM treatment groups,and principal coordinate analysis(PCoA)indicated significant clustering differences among the treatment groups.Microbial community analysis showed that strain A-4 significantly impacted the abundance of key bacteria in the rhizosphere of C.communis,increasing the relative abundance of Abditibacteriota and Gemmatimonadetes while decreasing the relative abundance of Parcubacteria.KEGG functional gene analysis indicated that the abundance of genes regulating glutathione
作者
王琛
谢更新
晏铭
晏卓逸
熊鑫
WANG Chen;XIE Gengxin;YAN Ming;YAN Zhuoyi;XIONG Xin(College of Environment and Ecology,Chongqing University,Chongqing,400044,China;College of Environmental Science and Engineering,Hunan University,Changsha,410082,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2024年第4期786-794,共9页
Chinese Journal of Applied and Environmental Biology
基金
装备预研教育部联合基金项目(8091B010103)
民用航天技术预先研究项目(6141A020221)资助。
关键词
耐锰微生物
锰污染土壤
鸭跖草
根际微生物
功能基因
manganese tolerant microorganism
manganese contaminated soil
Commelina communis
rhizosphere microorganism
functional gene
