Background:Potentilla sericea is a heavy metal hyperaccumulator landscaping plant. MYB transcription factors play an important role in regulating plant stress response to adversity. However, there are few studies on MYB transcription factors in stress tolerance in Potentilla sericea. In this study, the gene was successfully cloned from Potentilla sericea. Methods: Bioinformatic analysis and real-time quantitative PCR (qPCR) methods were used to evaluate this gene. The transgenic A. thaliana were obtained by flower dipping and the gene function was identified by determining physiological indicators under cadmium stress. Results: The open reading frame of is 942 bp, which encodes 313 amino acids (aa) and belongs to the R2R3 MYB transcription factor. The plant overexpression vector PBI121-PsMYB62-GFP was constructed and successfully transferred into A. thaliana. The relative expression level of PsMYB62was significantly increased by CdCl₂, NaCl, ABA, and mannitol treatments. The germination rate of transgenic seeds was higher than those of wild type (WT) and empty vector (EV) under different concentrations of cadmium treatment. Upon treatment with 100 μmol·L^-1 of CdCl₂·2.5H₂O, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the transgenic plants were significantly higher than those in the WT and EV. The contents of H₂O₂, O₂·^- and malondialdehyde (MDA) in transgenic lines were increased, but lower than those in WT and EV. The expression levels of AtGSH, AtPCS, and AtNAS4 that were related to the regulation of cadmium were increased, but the expression levels of transgenic lines were higher than those of WT and EV. Conclusion: The above results showed that could be induced by cadmium and could improve the cadmium resistance of plants.

In this study, PsMYB2 was successfully cloned using cDNA from Potentilla sericea as a template. It was used to construct the plant overexpression vector pBI121- PsMYB2-GFP, which was transferred into Arabidopsis thaliana wild-type plants. We studied the gene function using real-time quantitative PCR and performed a preliminary characterization and analysis of the function of PsMYB2 under abiotic stresses. This study showed that under cadmium stress, the gene expression of PsMYB2 gene in roots, stems, and leaves was up to 3–6 times higher than the control. The germination rate of transgenic A. thaliana T3 generation seeds reached more than 95%. The O₂·⁻, H₂O₂, and malondialdehyde contents of the transgenic P. sericea plant lines were increased but lower than those of the wild-type strain. The superoxide dismutase, peroxidase, and hydrogen peroxidase activities were increased in both wild-type and transgenic strains, and the transgenic strains showed higher enzyme activities than the wild-type. We concluded that PsMYB2 could improve plant resistance to cadmium, which provides a theoretical basis for using transgenic plants to remediate cadmium-contaminated soil and for sustainable land use.