Arsenic, both a toxin and a carcinogen, is a pervasive environmental contaminant of food and water that threatens the health of tens of millions people worldwide. The major source of dietary arsenic is from eating plants such as rice that have accumulated arsenic. While the process of how arsenic is taken into roots and shoots of plants is fairly well understood, little is known about how arsenic gets into seeds.

Zijuan Liu, Oakland University, Rochester, MI, USA, Yong-Guan Zhu, Chinese Academy of Sciences, Beijing, China, and colleagues discovered how arsenic builds up in the seeds of plants similar to rice. The plant Arabidopsis thaliana, which is used as a model for food plants such as rice, uses the inositol transporters AtINT2 and AtINT4 to load arsenite, the toxic form of arsenic, into seeds. This is the first identification of transporters responsible for arsenic accumulation in seeds. The same pathway could be present in rice grains.

The researchers think that these discoveries will enable the development of new rice cultivars with less arsenic in the grain.

• Inositol transporters AtINT2 and AtINT4 regulate arsenic accumulation in Arabidopsis seeds,
  Gui-Lan Duan, Ying Hu, Sabine Schneider, Joseph McDermott, Jian Chen, Norbert Sauer, Barry P. Rosen, Birgit Daus, Zijuan Liu, Yong-Guan Zhu,
  Nature Plants 2015.
  DOI: 10.1038/nplants.2015.202