Sometime early 2017, plant biologist Dr Abidur Rahman told me in an interview in Dhaka that his research team in Japan was working on plants’ molecular mechanism to absorb soil contaminants.
Four years down the line, this Bangladeshi scientist led a researchers’ team successfully showing the world the feasibility of cleaning up contaminated soil using the phytoremediation technique.
Phytoremediation is the direct use of living green plants for removal, degradation or containment of contaminants in soils.
Japan’s Iwate University on Tuesday announced that a team led by Dr Abidur Rahman “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 team’s findings were published in the international science journal Molecular Plant on February 12.
“What does the discovery of the potassium-independent cesium transporter mean to the world?” I posed this question to Dr Abidur Rahman on Wednesday as the scientist was busy being interviewed by Japanese and international media and basking in the glory of his team’s success.
He offered me the following explanation for a layman’s understanding.
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.
Plant biologist Dr Abidur Rahman | Collected
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 over-expressors to absorb sufficient cesium from the soil, as the soil will be depleted of potassium, resulting in an environment where no plants will be able to grow.
In search of a solution to clean up the soil, Dr Abidur’s research group discovered for the first time the potassium-independent cesium uptake protein and its causative gene. This work demonstrates the possibility that plants can absorb radioactive cesium efficiently without depleting soil potassium.
The world has witnessed the horrors of nuclear power plant accidents – as happened in Ukraine in 1986 and in Japan in 2011 – both causing a release of tons of radioactive cesium to the environment. Consequently, radioactive cesium found its way to the surrounding land, river, into plants and animal feed, and eventually to our food cycle and ecosystem.
Dr Abidur Rahman, who has a state-of-the-art lab named after him -- “The Abidur Lab” at Iwate University's Agriculture Faculty -- along with his research team discovered two binding proteins – ABCG33 and ABCG37 – which help plants’ uptake of cesium independent of potassium.
The researchers, who belong to Iwate University, Shimane University and the University of Tokyo, have demonstrated the functionality of these two proteins by showing that when higher proteins are expressed greater cesium uptakes occur.
Iwate University said in a press release on Tuesday, “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.”
Dr Abidur Rahman, who has been a senior postdoctoral researcher at the University of Massachusetts and has served at the Japan Atomic Energy Research Institute, has long been teaching at the Department of Plant Bio Science of Iwate University.
He sits on the editorial boards of three prestigious science journals -- PLOS ONE, Journal of Plant Growth Regulation and Frontiers in Plant Science while Iwate University’s ‘The Abidur Lab’ is engaged in, among other things, understanding the role of auxin (plant hormone) in the growth of plants' roots. A better understanding, Abidur hopes, will give them inroads to developing drought-tolerant crop varieties.
The other members of the research group are Prof Keitaro Tanoi and Ryohei Sugita of the University of Tokyo, Dr Takashi Akihiro of Shimane University and Mohammad Arif Ashraf, Sayaka Kumaga and Keita Ito of Iwate University.
