US EPA

1015742 

Journal Article 

Do radial oxygen loss and external aeration affect iron plaque formation and arsenic accumulation and speciation in rice? 

Wu, C; Ye, Z; Li, H; Wu, S; Deng, D; Zhu, Y; Wong, M 

2012 

Yes 

Journal of Experimental Botany
ISSN: 0022-0957
EISSN: 1460-2431 

63 

8 

2961-2970 

English 

22345639 

10.1093/jxb/ers017 

WOS:000304196900010 

Hydroponic experiments were conducted to investigate the effect of radial oxygen loss (ROL) and external aeration on iron (Fe) plaque formation, and arsenic (As) accumulation and speciation in rice (Oryza sativa L.). The data showed that there were significant correlations between ROL and Fe concentrations in Fe plaque produced on different genotypes of rice. There were also significant differences in the amounts of Fe plaque formed between different genotypes in different positions of roots and under different aeration conditions (aerated, normal, and stagnant treatments). In aerated treatments, rice tended to have a higher Fe plaque formation than in a stagnant solution, with the greatest formation at the root tip decreasing with increasing distances away, in accordance with a trend of spatial ROL. Genotypes with higher rates of ROL induced higher degrees of Fe plaque formation. Plaques sequestered As on rice roots, with arsenate almost double that with arsenite, leading to decreased As accumulation in both roots and shoots. The major As species detected in roots and shoots was arsenite, ranging from 34 to 78% of the total As in the different treatments and genotypes. These results contribute to our understanding of genotypic differences in As uptake by rice and the mechanisms causing rice genotypes with higher ROL to show lower overall As accumulation. 

arsenic (As); arsenate; arsenite; iron plaque; radial oxygen loss; rice; spatial pattern of ROL