title: Improvement of cadmium uptake and accumulation in Sedum alfredii by endophytic bacteria Sphingomonas SaMR12: effects on plant growth and root exudates.
abstract: Inoculating endophytic bacteria was proven as a promising way to enhance phytoremediation. By a hydroponic experiment, the role of this study was to clarify the effects of inoculating endophytic bacterium Sphingomonas SaMR12 on phytoremediation, with special emphasis on changes of cadmium uptake, plant growth, root morphology, and organic acids secretion at different cadmium treated levels (0, 5, 50, and 100 μM). The results showed that SaMR12 inoculation improved the accumulation of cadmium as well as plant biomass, length of roots, number of root tips, and root surface area. Root secretion of oxalic, citric, and succinic acids was also increased after inoculated, which may alleviate the cadmium toxicity to plant or inhibit the rising trend of oxidative stress of plant. The major finding of this work suggested that in the root, SaMR12 improves cadmium bioavailability and absorption facility by increasing root-soil contact area and root organic acid secretion; and in the shoot, SaMR12 increases cadmium tolerance by alleviating oxidative stress of plant, so as to enhance the capability of cadmium extraction by plant.
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Bao
authors.initials: B
authors.lastname: Chen
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Yibin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Muhammad Tariq
authors.initials: MT
authors.lastname: Rafiq
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Kiran Yasmin
authors.initials: KY
authors.lastname: Khan
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Fengshan
authors.initials: F
authors.lastname: Pan
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Xiaoe
authors.initials: X
authors.lastname: Yang
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China. Electronic address: yfeng@zju.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Feng
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism*; D060026:Endophytes / Q000378:metabolism; D005122:Exudates and Transudates / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000378:metabolism / Q000382:microbiology; D031963:Sedum / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*; D012989:Soil Pollutants / Q000378:metabolism*; D020578:Sphingomonas / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D002104:Cadmium
keywords: Microbe-assistant phytoremediation; Organic acid; Plant growth promoting bacteria; Reactive oxygen species; Root morphology