【Press release】The long-sought potassium-independent cesium transporters have been identified



In collaboration with National University corporation Shimane University and The University of Tokyo, Iwate University, for the first time in the world, discovered the potassium-independent cesium transporter and have shown the feasibility of cleaning up the contaminated soil using phytoremediation technique. The research group includes Dr. Takashi Akihiro, Faculty of Life and Environmental Science, Shimane University, Dr. Keitaro Tanoi of Graduate School of Agricultural Life Sciences, University of Tokyo, Dr. Mohammad Arif Ashraf, United Graduate School of Agricultural Sciences, Iwate University, Keita Ito, Graduate School of Integrated Arts and Sciences, Iwate University, Sayaka Kumagai Faculty of Agriculture, Dept. of Plant Bio Sciences, Iwate University and led by Dr. Abidur Rahman, Faculty of Agriculture and Next generation Agri Innovation Center, Iwate University.

Radioactive cesium accumulates in the soil in a nuclear accident and causes serious soil pollution problems. Soil is also polluted with other toxic metals such as cadmium and arsenic. In search of a solution to clean up the soils, this research group focused on a method called phytoremediation. This method uses plants (phytochemicals) to absorb harmful substances in the soil and purify the soil (remediation). Previous findings indicate that cesium uses potassium transporters to be absorbed in the plant. Since potassium is an essential element, it is impractical to use potassium transporter overexpressors to absorb sufficient cesium from soil, as the soil will be depleted of potassium, resulting in an environment where no plants will be able to grow. In this study, the group discovered for the first time potassium-independent cesium uptake proteins and its causative gene. This work demonstrates the possibility that plants can absorb radioactive cesium efficiently without depleting soil potassium, and open to the realization of a complete phytoremediation method for radioactive cesium contaminated soil that has not been established so far.

The results of this research will be published in the scientific journal "Molecular Plant" published by Cell Press on February 13, 2021 (JST).

Highlights of the research
(1) Discovered ABCG33 and ABCG37, which are potassium-independent cesium uptake carriers.
(2) Demonstrated the functionality of ABCG33 and ABCG37 in cesium uptake using yeast system. Radioactive cesium uptake was increased when ABCG33 and ABCG37 are expressed in yeast.
(3) It is expected that plants overexpressing ABCG33 and ABCG37 can be used to realize the phytoremediation method to clean up the soil contaminated with radioactive cesium.

・Iwate University grant for high-level research; JSPS Kakenhi Kiban B(Iwate University, Abidur Rahman, Associate Professor)
・JSPS Kakenhi Kiban C (Shimane University, Takashi Akihiro, Assistant Professor)
・Japan Science and Technology Agency (JST) [PRESTO]( University of Tokyo, Keitaro Tanoi, Professor)

Journal:Molecular Plant (Cell Press)
Title:ATP Binding Cassette Proteins ABCG37 and ABCG33 function as potassium independent cesium uptake carriers in Arabidopsis roots
Mohammad Arif Ashraf- United graduate School of Agricultural Science, Iwate University-former Ph.D. student
Takashi Akihiro- Faculty of Life and Environmental Science, Shimane University-Assistant Professor
Keita Ito- Faculty of Agriculture, Dept. of Plant Bio Sciences, Iwate University-Master's student (2nd year)
Sayaka Kumaga- Faculty of Agriculture, Dept. of Plant Bio Sciences, Iwate University-Undergraduate student (4th year) (graduated)
Ryohei Sugita- Graduate School of Agricultural and Life Sciences, The University of Tokyo- Assistant Professor
Keitaro Tanoi- Graduate School of Agricultural and Life Sciences, The University of Tokyo- PRESTO, Professor
Abidur Rahman- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Agri Innovation Center, Iwate University, United graduate School of Agricultural Sciences- Associate Professor
Publication date:2021. 2. 13
DOI: 10.1016/j.molp.2021.02.002

Press release(English)