Distribution characteristics and tolerance threshold of organ-subcellular rare earth elements in Dicranopteris pedata

Dicranopteris pedata is the strongest rare earth hyperaccumulator known to date, but its tolerance to rare earths has not been elucidated. In this study, Dicranopteris pedata in the mining area was taken as the research object, and the addition experiments of representative rare earth elements cerium and yttrium were carried out to analyze the rare earth enrichment characteristics of different organs and subcellular components of Dicranopteris pedata under different rare earth concentrations. The results showed that : ( 1 ) The total amount of cerium in Dicranopteris pedata increased with the increase of rare earth concentration, and the maximum tolerance concentration of yttrium was 0.8 mmol / L. ( 2 ) When the concentration of cerium and yttrium was ≤ 0.8mmol / L, the rare earth content in each organ of Dicranopteris pedata was leaf > rhizome > petiole, while the concentration was 1.6mmol / L, it was different. ( 3 ) The enrichment coefficient of light rare earth cerium is greater than that of heavy rare earth yttrium. ( 4 ) Cerium and yttrium in the leaves and roots of Dicranopteris pedata distributed in the cell wall accounted for the largest proportion, and the proportion of cerium and yttrium in the leaf cell wall increased with the increase of rare earth concentration. ( 5 ) There were significant differences in the proportion of cerium and yttrium in the subcellular components of Dicranopteris pedata petioles at low and high concentrations. Dicranopteris pedata has strong tolerance and enrichment ability to rare earth elements. The aboveground part ( especially the leaves ) of Dicranopteris pedata can effectively regulate the distribution of rare earth elements through compartmentalization isolation, and the enrichment ability of light rare earth cerium is stronger than that of heavy rare earth yttrium. The cell wall is the key part of rare earth accumulation, but when the rare earth concentration exceeds the tolerance threshold, the rare earth distribution pattern of each organ will change significantly. The results of this study can provide a theoretical basis for the remediation of soil rare earth pollution by using rare earth hyperaccumulator Dicranopteris pedata.