Effect of arsenic species on the growth and arsenic accumulation in Cucumis sativus.

The effects of arsenic (As) species, such as As(III), As(V) and dimethylarsinic acid (DMA), on the accumulation of As in cucumber (Cucumis sativus), as well as on its growth in a soil mesocosm were evaluated. When Cucumis sativus was cultivated in soils contaminated with 20 and 50 mg/kg of As(III), As(V) or DMA for 40 days, the growth was markedly inhibited by the inorganic As (As(III) and As(V)) rather than the organic As (DMA). Irrespective of the As species, the As concentrations accumulated in Cucumis sativus increased with increasing As concentration in the soil. The As bioaccumulation factors from soil into the tissue of Cucumis sativus were 17.5-35.4, 29.3-42.7 and 17.6-25.7 for As(III), As(V) and DMA, respectively. In addition, the As translocation factors from the roots to shoots were 0.025-0.031, 0.018-0.032 and 0.014-0.026 for As(III), As(V) and DMA, respectively. In conclusion, Cucumis sativus mainly accumulated As in its roots rather than its shoots and easily accumulated inorganic rather than organic As from the soil into its tissue.