Microbial driven iron reduction affects arsenic transformation and transportation in soil-rice system

Xue, S., Jiang, X., Wu, C., Hartley, W., Qian, Z., Luo, X. and Li, W. (2020) Microbial driven iron reduction affects arsenic transformation and transportation in soil-rice system. Environmental Pollution, 260. p. 114010.

[img] Text
Will Hartley Microbial driven upload.pdf - Accepted Version
Restricted to Repository staff only until 20 January 2021.
Available under License Creative Commons Attribution Non-commercial No Derivatives.

Download (1MB) | Request a copy

Abstract

The microbe-driven iron cycle plays an important role in speciation transformation and migration of arsenic (As) in soil-rice systems. In this study, pot experiments were used to investigate the effect of bacterial iron (Fe) reduction processes in soils on As speciation and migration, as well as on As uptake in soil-rice system. During the rice growth period, pH and electrical conductivity (EC) in soil solutions initially increased and then decreased, with the ranges of 7.4–8.8 and 116.3–820 mS cm−1, respectively. The concentrations of Fe, total As and As(III) showed an increasing trend in the rhizosphere and non-rhizosphere soil solutions with the increasing time. Fe concentrations were significantly positively correlated with total As and As(III) concentrations (***p < 0.001) in the soil solutions. The abundances of the arsenate reductase gene (arsC) and the As(III) S-adenosylmethionine methyltransferase gene (arsM) in rhizosphere soils were higher than those in non-rhizosphere soils, while the abundance of the Fe-reducing bacteria (Geo) showed an opposite trend. Moreover, it showed that the Geo abundance was significantly positively correlated with that of the arsC (***p < 0.001) and arsM (**p < 0.01) genes, respectively. The abundances of Geo, arsC and arsM genes were significantly positively correlated with the concentrations of Fe, total As and As(III) in the soil solutions (*p < 0.05). Moreover, the abundances of arsC and arsM genes were significantly negatively correlated with total As and As(III) in rice grains (*P < 0.05). These results showed that the interaction of bacterial Fe reduction process and radial oxygen loss from roots promoted the reduction and methylation of As, and then decreased As uptake by rice, which provided a theoretical basis for alleviating As pollution in paddy soils.

Item Type: Article
Keywords: Arsenic, Iron reduction, Speciation, Gene abundance, Rice
Divisions: Crop and Environment Sciences
Depositing User: Ms Kath Osborn
Date Deposited: 17 Feb 2020 10:56
Last Modified: 17 Feb 2020 10:56
URI: http://hau.repository.guildhe.ac.uk/id/eprint/17512

Actions (login required)

Edit Item Edit Item