Japan Atomic Energy Research Institute

About: Japan Atomic Energy Research Institute is a based out in . It is known for research contribution in the topics: Neutron & Irradiation. The organization has 7707 authors who have published 14471 publications receiving 207688 citations.

Rice plants take up iron as an Fe3+-phytosiderophore and as Fe2+.

Abstract: Summary Only graminaceous monocots possess the Strategy II iron (Fe)-uptake system in which Fe is absorbed by roots as an Fe3+-phytosiderophore. In spite of being a Strategy II plant, however, rice (Oryza sativa) contains the previously identified Fe2+ transporter OsIRT1. In this study, we isolated the OsIRT2 gene from rice, which is highly homologous to OsIRT1. Real-time PCR analysis revealed that OsIRT1 and OsIRT2 are expressed predominantly in roots, and these transporters are induced by low-Fe conditions. When expressed in yeast (Saccharomyces cerevisiae) cells, OsIRT2 cDNA reversed the growth defects of a yeast Fe-uptake mutant. This was similar to the effect of OsIRT1 cDNA. OsIRT1– and OsIRT2–green fluorescent protein fusion proteins localized to the plasma membrane when transiently expressed in onion (Allium cepa L.) epidermal cells. OsIRT1 promoter–GUS analysis revealed that OsIRT1 is expressed in the epidermis and exodermis of the elongating zone and in the inner layer of the cortex of the mature zone of Fe-deficient roots. OsIRT1 expression was also detected in the ccompanion cells. Analysis using the positron-emitting tracer imaging system showed that rice plants are able to take up both an Fe3+-phytosiderophore and Fe2+. This result indicates that, in addition to absorbing an Fe3+-phytosiderophore, rice possesses a novel Fe-uptake system that directly absorbs the Fe2+, a strategy that is advantageous for growth in submerged conditions.

THE NOVEL EXTRACTANTS, DIGLYCOLAMIDES, FOR THE EXTRACTION OF LANTHANIDES AND ACTINIDES IN HNO3–n-DODECANE SYSTEM

Abstract: The novel extractants, six diglycolamides synthesized in our laboratory, were investigated for actinide extraction from nitric acid into n-dodecane. The dependence of the distribution coefficients of Eu(III) and Am(III) on the length of alkyl chain in the extractants was examined. Among the diglycolamides studied, N,N,N′,N′-tetraoctyl-3-oxapentanediamide (TOOPDA) and N,N,N′,N′-tetradecyl-3-oxapentanediamide (TDOPDA) showed a sufficient solubility in n-dodecane, due to their appropriate lipophilicity modified by increasing the length of the alkyl chain attached to amidic N atoms. The distribution coefficients, D M, of actinides obtained by TOOPDA increased with an increase in HNO3 concentration. The number of diglycolamide molecules coordinated to the actinide ions was estimated to be three for Th(IV), U(VI), Pu(IV), and four for Am(III) and Cm(III) by slope analysis. The order of D M for the actinides at high nitric acid concentrations is An(III), An(IV) > An(VI) > An(V) and that for lanthanides, heavier ...