Methylated arsenic species in plants originate from soil microorganisms

A - Papers appearing in refereed journals

Lomax, C., Liu, W-J., Wu, Liyou, Xue, K., Xiong, J., Zhou, J., McGrath, S. P., Meharg, A. A., Miller, A. J. and Zhao, F-J. 2012. Methylated arsenic species in plants originate from soil microorganisms. New Phytologist. 193 (3), pp. 665-672.

AuthorsLomax, C., Liu, W-J., Wu, Liyou, Xue, K., Xiong, J., Zhou, J., McGrath, S. P., Meharg, A. A., Miller, A. J. and Zhao, F-J.
Abstract

Inorganic arsenic (iAs) is a ubiquitous human carcinogen, and rice (Oryza sativa) is the main contributor to iAs in the diet. Methylated pentavalent As species are less toxic and are routinely found in plants; however, it is currently unknown whether plants are able to methylate As. Rice, tomato (Solanum lycopersicum) and red clover (Trifolium pratense) were exposed to iAs, monomethylarsonic acid (MMA(V)), or dimethylarsinic acid (DMA(V)), under axenic conditions. Rice seedlings were also grown in two soils under nonsterile flooded conditions, and rice plants exposed to arsenite or DMA(V) were grown to maturity in nonsterile hydroponic culture. Arsenic speciation in samples was determined by HPLC-ICP-MS. Methylated arsenicals were not found in the three plant species exposed to iAs under axenic conditions. Axenically grown rice was able to take up MMA(V) or DMA(V), and reduce MMA(V) to MMA(III) but not convert it to DMA(V). Methylated As was detected in the shoots of soil-grown rice, and in rice grain from nonsterile hydroponic culture. GeoChip analysis of microbial genes in a Bangladeshi paddy soil showed the presence of the microbial As methyltransferase gene arsM. Our results suggest that plants are unable to methylate iAs, and instead take up methylated As produced by microorganisms.

KeywordsPlant Sciences
Year of Publication2012
JournalNew Phytologist
Journal citation193 (3), pp. 665-672
Digital Object Identifier (DOI)doi:10.1111/j.1469-8137.2011.03956.x
PubMed ID22098145
Open accessPublished as bronze (free) open access
FunderBiotechnology and Biological Sciences Research Council
Rothamsted International fellowship
Rothamsted Research
National Natural Science Foundation of China
Funder project or codeSEF
Trace element dynamics in soils and plant uptake
Soil protection and remediation
BBSRC Quota Studentship: Decreasing arsenic accumulation in rice to reduce health risk
Publisher's version
Output statusPublished
Publication dates
Online18 Nov 2011
Publication process dates
Accepted04 Oct 2011
Copyright licenseCC BY
PublisherWiley
ISSN0028-646X

Permalink - https://repository.rothamsted.ac.uk/item/8q9x3/methylated-arsenic-species-in-plants-originate-from-soil-microorganisms

8 total views
3 total downloads
1 views this month
0 downloads this month
Download files as zip