Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0802361105 (2008)

Rice is efficient, indeed disconcertingly so, at assimilating arsenic from the soils of paddy fields. But how it does this has been unclear. Now Fang-Jie Zhao at Rothamsted Research in Harpenden, UK, Jian Feng Ma at Okayama University in Japan and their colleagues have discovered that it is taken into the plant as though it were silicon.

They found that two transporter proteins belonging to the family known as aquaporins enable arsenite to move from rice's soggy surroundings into its vascular system. Mutations in the genes encoding either of these proteins reduced arsenite uptake by the roots and the amount of arsenic that accumulated in shoots and grains.

The authors hope that different versions of these genes exist that favour silicon transport over that of arsenite. If so, rice carrying such versions could be planted in regions of the world where arsenic poisoning is a problem.