Physiological Response Mechanism of Dicranopteris pedata under Different Concentrations of Cerium Treatment

In order to investigate the effect of the rare earth element cerium（Ce）on the physiological characteristics of Dicranopteris pedata,this study was conducted as a controlled experiment in the laboratory of the School of Geosciences, Fujian Normal University in 2024.The peroxidase（POD）,catalase（CAT）,superoxide dismutase（SOD）activities of Dicranopteris pedata leaves were systematically measured by soil addition of different concentrations of cerium chloride CeCl₃·7H₂O,set at gradients of 0,200,400,800,1200 and 1600 mg·kg^-1,and the activities of malondialdehyde（MDA）,proline（Pro）,total chlorophyll（Chl）,relative electrical conductivity（REC）,soluble sugars（SS）,hydrogen peroxide（H₂O₂）,superoxide anion（O₂^-）,and sucrose phosphorylase（SP）content were measured as physiological indicators.The results showed that low concentration of cerium treatment(≤400mg·kg^-1)significantly promoted chlorophyll synthesis（maximum increase of 53.9%）and antioxidant enzymes（SOD,POD,CAT）activities of Dicranopteris pedata,while inducing the accumulation of osmoregulatory substances（Pro, SS）.However, high concentration of cerium treatment(≥800 mg·kg^-1) resulted in increased content of membrane lipid peroxidation product MDA(27.13 nmol·g^-1) and enhanced cell membrane permeability（74.0% increase in REC）,suggesting the generation of oxidative stress.Dicranopteris pedata mitigates Cerium toxicity by dynamically regulating the antioxidant system and carbon metabolism, and its ability to enrich Cerium and physiological plasticity make it an ideal species for ecological remediation in rare earth mining areas.This study provides the theoretical basis and technical reference for the phytoremediation of rare earth-contaminated soil.