Investigations On The Phytotoxicity Of Perfluorooctanoic Acid In Arabidopsis Thaliana

As a persistent environmental pollutant,perfluorooctanoic acid(PFOA)is the hot spot of current research.Previous studies have shown that PFOA will be enriched in organisms.High concentrations of PFOA in plants can cause serious growth and developmental toxicity,but the mechanism of toxic effects is still unclear.Therefore,this study analyzed the toxic effects and toxicity mechanisms of Arabidopsis thaliana caused by PFOA by transcriptome data analysis and related index determination.The toxic effects of PFOA on Arabidopsis thaliana phenotype were: the accumulation of fresh weight in shoots and roots of plants decreased,the number of lateral roots decreased and the chlorophyll content in leaves decreased.Since PFOA is mainly transported into shoots after being absorbed by plants,the toxicity of PFOA to Arabidopsis thaliana leaves is significantly more severe than that of roots.Arabidopsis needs active transmembrane transporters to absorb and transport PFOA.Through transcriptome analysis,we found that the transcription of drug transmembrane transporters,active transmembrane transporters,and ion transmembrane transporterrelated genes was up-regulated in shoots and leaves,and 12 of them were overlapping genes.These overlapping genes may be involved in the transport of PFOA from roots to shoots.The accumulation of PFOA in Arabidopsis thaliana caused a violent response of iron-deficient genes,while the content of iron in the shoots and roots of did not change significantly compared with the control group,indicating that the response of PFOAinduced iron deficiency genes has nothing to do with iron content.The up-regulation of iron uptake genes in Arabidopsis roots promotes the absorption of iron by roots,while the down-regulation of iron transporters in roots may inhibit the transport of iron from roots to leaves,resulting in the absorption of iron from Arabidopsis at the roots.In addition,the action of PFOA also triggers the response of redox genes in plants,and the leaves are higher than the roots.Through transcriptome analysis,it was found that the transcript abundance of glutathione S-transferase and uridine diphosphate glycosyltransferase increased significantly,and these two types of proteins play an important role in the detoxification of plant organic substances.In order to analyze the redox state in plants,we measured the antioxidant index in plants and found that the glutathione content and glutathione reductase activity in plants increased with the action of PFOA.These results indicated that PFOA caused oxidative stress on Arabidopsis thaliana.Therefore,this study not only reveals the toxic effects of different concentrations of PFOA,but also provides new ideas for the study of the mechanism of PFOA toxicity at the molecular level.