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Lin Z, Wang X, Wu X, Liu D, Yin Y, Zhang Y, Xiao S, Xing B. Nitrate reduced arsenic redox transformation and transfer in flooded paddy soil-rice system. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 243:1015-1025. [PMID: 30248601 DOI: 10.1016/j.envpol.2018.09.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/19/2018] [Accepted: 09/10/2018] [Indexed: 06/08/2023]
Abstract
Inhibition of reductive transformation of arsenic (As) in flooded paddy soils is of fundamental importance for mitigating As transfer into food chain. Anaerobic arsenite (As(III)) oxidizers maintain As in less mobile fraction under nitrate-reducing conditions. In this study, we explored the dynamic profile of As speciation in porewater and As distribution among the pools of differential bioavailability in soil solid phase with and without nitrate treatment. In parallel, the abundance and diversity of As(III) oxidase gene (aioA) in flooded paddy soil with nitrate amendment was examined by quantitative PCR and aioA gene clone library. Furthermore, the impact of nitrate on As accumulation and speciation in rice seedlings was unraveled. With nitrate addition (25 mmol NO3- kg-1 soil), porewater As(III) was maintained at a consistently negligible concentration in the flooded paddy soil and the reductive dissolution of As-bearing Fe oxides/hydroxides was significantly restrained. Specifically, nitrate amendment kept 81% of total soil As in the nonlabile fraction with arsenate (As(V)) dominating after 30 days of flooding, compared to only 61% in the unamended control. Nitrate treatment induced 4-fold higher abundance of aioA gene, which belonged to domains of bacteria and archaea under the classes α-Proteobacteria (6%), ß-Proteobacteria (90%), ɣ-Proteobacteria (2%), and Thermoprotei (2%). By nitrate addition, As accumulation in rice seedlings was decreased by 85% with simultaneously elevated As(V) ratio in rice plant relative to control after 22 days of growth under flooded conditions. These results highlight that nitrate application can serve an efficient method to inhibit reductive dissolution of As in flooded paddy soils, and hence diminish As uptake by rice under anaerobic growing conditions.
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Affiliation(s)
- Zhaojun Lin
- College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Xin Wang
- College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China; Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, 01003, United States.
| | - Xin Wu
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences/National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, 410125, China
| | - Daihuan Liu
- Hunan Yonker Environmental Protection Research Institute Co., Ltd., Changsha, 410330, China
| | - Yulong Yin
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences/National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, 410125, China
| | - Yue Zhang
- College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Sha Xiao
- College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, 01003, United States
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Dahlawi S, Naeem A, Iqbal M, Farooq MA, Bibi S, Rengel Z. Opportunities and challenges in the use of mineral nutrition for minimizing arsenic toxicity and accumulation in rice: A critical review. CHEMOSPHERE 2018; 194:171-188. [PMID: 29202269 DOI: 10.1016/j.chemosphere.2017.11.149] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 11/21/2017] [Accepted: 11/25/2017] [Indexed: 06/07/2023]
Abstract
Growing rice on arsenic (As)-contaminated soil or irrigating with As-contaminated water leads to significant accumulation of As in grains. Moreover, rice accumulates more As into grains than other cereal crops. Thus, rice consumption has been identified as a major route of human exposure to As in many countries. Inorganic As species are carcinogenic and could pose a considerable health risk to humans even at low dietary concentration. Genotypic variation and concentration of nutrients such as iron, manganese, phosphate, sulfur and silicon are the two main factors that affect As accumulation in rice grains. Therefore, in addition to better growth and yield of plants, application of specific nutrients in optimum quantities offers an added benefit of decreasing As content in rice grains. These nutrient elements influence speciation of As in rhizosphere, compete with As for root uptake and interfere with As translocations to the shoot and ultimately accumulation in grains. This papers critically appraises the methods, forms and rate of application, mechanisms and extent of efficiency of different mineral nutrients in decreasing As accumulation in rice grains.
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Affiliation(s)
- Saad Dahlawi
- Department of Environmental Health, College of Public Health, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; Institute for Research and Medical Consultation (IRMC), Imam Abdulrehman Bin Faisal University, P.O. Box 1982, Dammam, 31441, Saudi Arabia
| | - Asif Naeem
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan; Nuclear Institute of Agriculture and Biology, Jhang Road, Faisalabad, Pakistan
| | - Muhammad Iqbal
- Department of Botany, Jamia Hamdard (Hamdard University), New Delhi, India
| | - Muhammad Ansar Farooq
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
| | - Sadia Bibi
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
| | - Zed Rengel
- School of Agriculture and Environment, University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
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