Location: Water Management ResearchTitle: A novel selenocystine-accumulating plant in selenium-mine seepage area of Yutangba, China Author
Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2013
Publication Date: 6/4/2013
Publication URL: http://DOI:101371/JOURNAL.PONE.0065615
Citation: Yuan, L., Qi, Y., Zhu, Y., Yin, X., Banuelos, G.S. 2013. A novel selenocystine-accumulating plant in selenium-mine seepage area of Yutangba, China. PLoS One. 8(6):e65615. Interpretive Summary: Yutangba is the only selenium (Se) mine in the world with Se content as high as 8500 mg/kg. Human activities, such as coal-mining, coal-burning and lime application to soil, have played an important role in the distribution and transportation of Se within the soil. Consequently, the Se-mine seepage areas contain high levels of bioavailable Se, and it is likely that Se-accumulating plants exist there. In this study, we are trying to identify Se-hyperaccumulating plants that could be useful for Se-phytoremediation strategies. After potential Se-accumulating plant species have been identified, Se speciation analysis was performed on the plant tissue to determine the forms of Se contained within these plant species. The results showed a plant species in the sunflower family accumulated a high amounts of Se that would allow this plant to be considered as a secondary Se-accumulating plant species. Importantly, over 99% of the total plant Se was identified as selenocystine, which has been reported to have potential anti-carcinogenic properties. Future research will be conducted to evaluate both the plants ability to grow on a field scale and phytomanage Se from Se-contaminated soils.
Technical Abstract: Yutangba, located in the northwestern Hubei province, China, is the only selenium (Se) mine in the world with Se content as high as 8500 mg/kg. High Se concentrations in water and soil can be collected from certain restricted areas near abandoned stone coal spoils. In the seepage areas of Se mines, on-site plants (i.e., Adenocaulon himalaicum-Asteraceae) were collected that appeared to be thriving under such soil conditions. They were analyzed for Se content and Se speciation analysis were also performed. The results showed that the Asteraceae accumulated more than 1000 mg Se/kg DW. This kind of secondary Se-accumulating plant extracted Se from the underlying sediments with bio-concentration factors more than 10, which is higher than other plant species. Moreover, up to 99% of the total plant Se was identified as selenocystine (SeCys). This form of Se is likely the result of a unique Se-metabolism pathway that has helped the plant survive in extreme Se growing conditions. This newly-identified plant may provide a beneficial source of Se for Se-biofortification purposes, since SeCys has been reported to have potential anti-carcinogenic properties, and be useful for phytomanaging Se from Se-laden soils.