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Plant Physiol
2009 Aug 01;1504:2071-80. doi: 10.1104/pp.109.140350.
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The rice aquaporin Lsi1 mediates uptake of methylated arsenic species.
Li RY
,
Ago Y
,
Liu WJ
,
Mitani N
,
Feldmann J
,
McGrath SP
,
Ma JF
,
Zhao FJ
.
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Pentavalent methylated arsenic (As) species such as monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)] are used as herbicides or pesticides, and can also be synthesized by soil microorganisms or algae through As methylation. The mechanism of MMA(V) and DMA(V) uptake remains unknown. Recent studies have shown that arsenite is taken up by rice (Oryza sativa) roots through two silicon transporters, Lsi1 (the aquaporin NIP2;1) and Lsi2 (an efflux carrier). Here we investigated whether these two transporters also mediate the uptake of MMA(V) and DMA(V). MMA(V) was partly reduced to trivalent MMA(III) in rice roots, but only MMA(V) was translocated to shoots. DMA(V) was stable in plants. The rice lsi1 mutant lost about 80% and 50% of the uptake capacity for MMA(V) and DMA(V), respectively, compared with the wild-type rice, whereas Lsi2 mutation had little effect. The short-term uptake kinetics of MMA(V) can be described by a Michaelis-Menten plus linear model, with the wild type having 3.5-fold higher V(max) than the lsi1 mutant. The uptake kinetics of DMA(V) were linear with the slope being 2.8-fold higher in the wild type than the lsi1 mutant. Heterologous expression of Lsi1 in Xenopus laevis oocytes significantly increased the uptake of MMA(V) but not DMA(V), possibly because of a very limited uptake of the latter. Uptake of MMA(V) and DMA(V) by wild-type rice was increased as the pH of the medium decreased, consistent with an increasing proportion of the undissociated species. The results demonstrate that Lsi1 mediates the uptake of undissociated methylated As in rice roots.
Abedin,
Uptake kinetics of arsenic species in rice plants.
2002, Pubmed
Abedin,
Uptake kinetics of arsenic species in rice plants.
2002,
Pubmed
Aposhian,
A review of the enzymology of arsenic metabolism and a new potential role of hydrogen peroxide in the detoxication of the trivalent arsenic species.
2004,
Pubmed
Bentley,
Microbial methylation of metalloids: arsenic, antimony, and bismuth.
2002,
Pubmed
Bienert,
A subgroup of plant aquaporins facilitate the bi-directional diffusion of As(OH)3 and Sb(OH)3 across membranes.
2008,
Pubmed
Burló,
Arsenic species: effects on and accumulation by tomato plants.
1999,
Pubmed
Carbonell-Barrachina,
Arsenic toxicity and accumulation in turnip as affected by arsenic chemical speciation.
1999,
Pubmed
Chakraborti,
Arsenic calamity in the Indian subcontinent What lessons have been learned?
2002,
Pubmed
Dixon,
Enzyme activities and subcellular localization of members of the Arabidopsis glutathione transferase superfamily.
2009,
Pubmed
Isayenkov,
The Arabidopsis thaliana aquaglyceroporin AtNIP7;1 is a pathway for arsenite uptake.
2008,
Pubmed
Kamiya,
NIP1;1, an aquaporin homolog, determines the arsenite sensitivity of Arabidopsis thaliana.
2009,
Pubmed
,
Xenbase
Kile,
Dietary arsenic exposure in bangladesh.
2007,
Pubmed
Li,
Mitigation of arsenic accumulation in rice with water management and silicon fertilization.
2009,
Pubmed
Liu,
Methylarsonous acid transport by aquaglyceroporins.
2006,
Pubmed
Ma,
Transporters of arsenite in rice and their role in arsenic accumulation in rice grain.
2008,
Pubmed
,
Xenbase
Ma,
Functions and transport of silicon in plants.
2008,
Pubmed
Ma,
A rice mutant defective in Si uptake.
2002,
Pubmed
Ma,
An efflux transporter of silicon in rice.
2007,
Pubmed
Ma,
A silicon transporter in rice.
2006,
Pubmed
Maurel,
Plant aquaporins: membrane channels with multiple integrated functions.
2008,
Pubmed
Meharg,
Geographical variation in total and inorganic arsenic content of polished (white) rice.
2009,
Pubmed
Mitani,
Characterization of substrate specificity of a rice silicon transporter, Lsi1.
2008,
Pubmed
,
Xenbase
Nordstrom,
Public health. Worldwide occurrences of arsenic in ground water.
2002,
Pubmed
Ohno,
Arsenic intake via water and food by a population living in an arsenic-affected area of Bangladesh.
2007,
Pubmed
Petrick,
Monomethylarsonous acid (MMA(III)) is more toxic than arsenite in Chang human hepatocytes.
2000,
Pubmed
Raab,
Uptake, translocation and transformation of arsenate and arsenite in sunflower (Helianthus annuus): formation of arsenic-phytochelatin complexes during exposure to high arsenic concentrations.
2005,
Pubmed
Sakurai,
Identification of 33 rice aquaporin genes and analysis of their expression and function.
2005,
Pubmed
Takahashi,
Arsenic behavior in paddy fields during the cycle of flooded and non-flooded periods.
2004,
Pubmed
Williams,
Greatly enhanced arsenic shoot assimilation in rice leads to elevated grain levels compared to wheat and barley.
2007,
Pubmed
Wu,
Methylation of arsenic in vitro by cell extracts from bentgrass (Agrostis tenuis): effect of acute exposure of plants to arsenate.
2002,
Pubmed
Xu,
Growing rice aerobically markedly decreases arsenic accumulation.
2008,
Pubmed
Xu,
Rapid reduction of arsenate in the medium mediated by plant roots.
2007,
Pubmed
Zavala,
Arsenic in rice: II. Arsenic speciation in USA grain and implications for human health.
2008,
Pubmed
Zhao,
Arsenic uptake and metabolism in plants.
2009,
Pubmed
Zhu,
Exposure to inorganic arsenic from rice: a global health issue?
2008,
Pubmed