RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
MEMPHYS, Center for BioMembrane Physics, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark.
Sci Rep. 2017 Feb 23;7:43170. doi: 10.1038/srep43170.
Phytoaccumulation is a technique to extract metals from soil utilising ability of plants. Cesium is a valuable metal while radioactive isotopes of cesium can be hazardous. In order to establish a more efficient phytoaccumulation system, small molecules which promote plants to accumulate cesium were investigated. Through chemical library screening, 14 chemicals were isolated as 'cesium accumulators' in Arabidopsis thaliana. Of those, methyl cysteinate, a derivative of cysteine, was found to function within the plant to accumulate externally supplemented cesium. Moreover, metabolite profiling demonstrated that cesium treatment increased cysteine levels in Arabidopsis. The cesium accumulation effect was not observed for other cysteine derivatives or amino acids on the cysteine metabolic pathway tested. Our results suggest that methyl cysteinate, potentially metabolised from cysteine, binds with cesium on the surface of the roots or inside plant cells and improve phytoaccumulation.
植物富集是一种利用植物的能力从土壤中提取金属的技术。铯是一种有价值的金属，而放射性铯同位素则具有危害性。为了建立更有效的植物富集系统，研究了促进植物积累铯的小分子。通过化学文库筛选，从拟南芥中分离出 14 种作为“铯积累剂”的化学物质。其中，半胱氨酸的衍生物甲基半胱氨酸被发现可在植物体内发挥作用，积累外部补充的铯。此外，代谢物分析表明，铯处理增加了拟南芥中的半胱氨酸水平。在测试的半胱氨酸代谢途径中，其他半胱氨酸衍生物或氨基酸没有观察到铯积累效应。我们的结果表明，甲基半胱氨酸可能由半胱氨酸代谢生成，与根表面或植物细胞内的铯结合，从而提高植物富集能力。
