title: Enhancement of Cd phytoextraction by two Amaranthus species with endophytic Rahnella sp. JN27.
abstract: Microbe-assisted phytoextraction shows a potential for the remediation of metal-contaminated soils. The aim of this study was to isolate, characterize, and evaluate the potential of endophytic bacteria in improving plant growth and metal uptake by Cd-hyperaccumulators-Amaranthus hypochondriacus and Amaranthus mangostanus. An endophytic bacterial strain JN27 isolated from roots of Zea mays displayed high tolerance and mobilization to Cd, and was identified as Rahnella sp. based on 16S rDNA sequencing. The strain also exhibited multiple plant growth beneficial features including the production of indole-3-acetic acid, siderophore, 1-aminocyclopropane-1-carboxylic acid deaminase and solubilization of insoluble phosphate. Subsequently, a pot trial was performed to elucidate the effects of inoculation with JN27 on plant growth and Cd uptake by A. hypochondriacus, A. mangostanus, Solanum nigrum and Z. mays grown in soils with different levels of Cd (25, 50, 100 mg Cd kg(-1)). The results revealed that inoculation with JN27 significantly increased the biomasses of all the tested plants and the Cd concentrations of all the tested plants except Z. mays in both above-ground and root tissues. Moreover, strain JN27 could successfully re-colonized in rhizosphere soils of all the tested plants and root interior of A. hypochondriacus and Z. mays. The present results indicated that the symbiont of A. hypochondriacus (or A. mangostanus) and strain JN27 can effectively improve the Cd uptake by plants and would be a new strategy in microbe-assisted phytoextraction for metal-contaminated soils.
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education and Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
authors: Ming
authors: M
authors: Yuan
authors: State Key Laboratory for Bio-control and School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, PR China.
authors: Huaidong
authors: H
authors: He
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education and Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
authors: Li
authors: L
authors: Xiao
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education and Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
authors: Ting
authors: T
authors: Zhong
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education and Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
authors: Hui
authors: H
authors: Liu
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education and Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
authors: Shubin
authors: S
authors: Li
authors: College of Chemistry and Environment, South China Normal University, Guangzhou 510631, PR China.
authors: Peiyan
authors: P
authors: Deng
authors: State Key Laboratory for Bio-control and School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, PR China.
authors: Zhihong
authors: Z
authors: Ye
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education and Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China. Electronic address: jingyx@scnu.edu.cn.
authors: Yuanxiao
authors: Y
authors: Jing
mesh_terms: D027721:Amaranthus / Q000145:classification / Q000378:metabolism*; D002104:Cadmium / Q000378:metabolism*; D019216:Metals, Heavy / Q000378:metabolism*; D063245:Plant Development; D018517:Plant Roots / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020638:Rahnella / Q000235:genetics / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D019216:Metals, Heavy; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D002104:Cadmium
keywords: Amaranthus hypochondriacus; Amaranthus mangostanus; Cd; Endophytic bacterium; Phytoextraction