title: Endophytic bacterium Sphingomonas SaMR12 promotes cadmium accumulation by increasing glutathione biosynthesis in Sedum alfredii Hance.
abstract: A hydroponic experiment was conducted to verify the effects of inoculation with endophytic bacteria Sphingomonas SaMR12 on root growth, cadmium (Cd) uptake, reactive oxygen species (ROS), antioxidases, glutathione (GSH) and the related gene expression of Sedum alfredii Hance under different levels of Cd such as 0, 10, 25, 100 and 400 μM. The results showed that inoculation of SaMR12 improved Cd accumulation and upregulated glutathione synthase (GS) expression, but slightly reduced malondialdehyde (MDA) concentration and alleviated Cd-induced damage in roots. However it didn't alter the activities of antioxidant enzymes. When Cd concentration exceeded 25 μM, SaMR12 increased the concentration of GSH and the expression level of GSH1. At high Cd treatment levels (100 and 400 μM), SaMR12 significantly reduced H2O2 concentration and enhanced expression level of 1-Cys peroxiredoxin PER1 and ATPS genes. These results indicate that although SaMR12 has no significant effects on antioxidases activities, it reduces H2O2 concentration by enhancing GSH concentration and relevant genes expression, and subsequently improves Cd tolerance and accumulation.
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Fengshan
authors.initials: F
authors.lastname: Pan
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Meng
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Sha
authors.initials: S
authors.lastname: Luo
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Bao
authors.initials: B
authors.lastname: Chen
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Kiran Yasmin
authors.initials: KY
authors.lastname: Khan
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Xiaoe
authors.initials: X
authors.lastname: Yang
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China. Electronic address: yfeng@zju.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Feng
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001692:Biological Transport; D002104:Cadmium / Q000378:metabolism*; D005978:Glutathione / Q000096:biosynthesis* / Q000378:metabolism; D005981:Glutathione Synthase / Q000096:biosynthesis*; D006861:Hydrogen Peroxide / Q000378:metabolism; D018527:Hydroponics; D008315:Malondialdehyde / Q000378:metabolism; D054464:Peroxiredoxins / Q000096:biosynthesis; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology; D031963:Sedum / Q000378:metabolism* / Q000382:microbiology; D020578:Sphingomonas / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D002104:Cadmium; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; D005981:Glutathione Synthase; D005978:Glutathione
keywords: Cd; Gene expression; Glutathione (GSH); Plant growth promoting bacteria; Reactive oxygen species (ROS)