Department of Plant Sciences

To elucidate the physiological and genetic mechanisms underlying arsenic (As) absorption and metabolism in rice, we used a set of diverse rice germplasms, called As World Rice Collection (WRC). These cultivars consist of 69 accessions which cover the genetic diversity of almost 32,000 accessions of cultivated rice. The collection was cultivated in a paddy field with naturally abundant level of As. Approximately three times difference at the maximum in grain As concentration was found in WRC. The dominant As species in grains was arsenite, followed by dimethyarsinic acid (DMA) and arsenate, irrespective of cultivars. However, the proportions of As species were different among rice cultivars. These results suggest the possibility that As absorption and metabolim in rice could be genetically controlled.