Mechanisms of water regime effects on uptake of cadmium and nitrate by two ecotypes of water spinach (Ipomoea aquatica Forsk.) in contaminated soil.
Chemosphere. 2020 May; 246:125798.C

Abstract

Availability of cadmium (Cd) and nitrate and their transfer to green leafy vegetables is highly dependent on physical, chemical and biochemical conditions of the soil. The phenotypic characteristics, accumulation of hazardous materials and rhizosphere properties of two ecotypes of water spinach in response to water stress were investigated. Flooding significantly enhanced plant growth and decreased Cd and nitrate concentrations in the shoot and root of both ecotypes of water spinach. Flooding extensively changed the physicochemical properties and biological processes in the rhizosphere, including increased pH and activities of urease and acid phosphatase, and decreased availability of Cd and nitrate and activity of nitrate reductase. Furthermore, flooding increased rhizosphere bacteria community diversity (including richness and evenness) and changed their community structure. Denitrifying bacteria (Clostridiales, Azoarcus and Pseudomonas), toxic metal resistant microorganisms (Rhodosporillaceae, Rhizobiales and Geobacter) were enriched in the rhizosphere under flooding conditions, and the plant growth-promoting taxa (Sphingomonadaceae) were preferentially colonized in the high accumulator (HA) rhizosphere region. These results indicated that flooding treatments result in biochemical and microbiological changes in soil, especially in the rhizosphere and reduced the availability of Cd and nitrate to plants, thus decreasing their uptake by water spinach. It is, therefore, possible to promote crop growth and reduce the accumulation of hazardous materials in vegetable crops like water spinach by controlling soil moisture conditions.

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Authors+Show Affiliations

Tang L
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
Hamid Y
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
Zehra A
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China; Department of Botany, Federal Urdu University of Arts, Science and Technology, Karachi, Pakistan.
Sahito ZA
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
He Z
University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, Florida, 34945, United States.
Khan MB
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
Feng Y
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
Yang X
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China. Electronic address: xeyang@zju.edu.cn.

MeSH

AgricultureBacteriaBiological TransportCadmiumEcotypeEnvironmental PollutionIpomoeaNitratesRhizosphereSoilSoil PollutantsVegetablesWater

Pub Type(s)

Journal Article

Language

eng

PubMed ID

31927376