The synthesis of pathogenesis-related proteins (PR) is one prominent feature of plant defense responses on abiotic or non-abiotic stress situations.According to the transcriptome data of Salvia miltiorrhiza,designing specific primers and using reverse transcription-polymerase chain reaction (RT-PCR),we isolated an open reading frame of pathogenesis-related protein 10 (PR10) from S.miltiorrhiza and named as SmPR10-1 (GenBank Accession No.KF877034).The results indicated that:(1)SmPR10-1 has an open reading frame (ORF) of 477 bp,which encoded a protein of 158 amino acid residues,with a predicted molecular mass of 17.38 kD.(2)Bioinformatic analysis indicated that SmPR10-1 protein showed the highest homology,69% identity,with PR10 protein from Vitis vinifera with the same conserved sequence (G-X-G-G-X-G) and (K-A-X-E-X-Y).(3)Escherichia coli BL21 cells were transformed with the expression vector pET32a-SmPR10-1 and used for prokaryotic expression.Meanwhile,the four factors,inducing IPTG concentrations,initial density of host bacterium (A₆₀₀),inducing temperature and inducing time,which influenced protein expression,were optimized.The optimum expression conditions of SmPR10-1 were final IPTG concentration of 0.4 mmol/L,A₆₀₀ of 0.8,and the inducing time of 8 h at 30 ℃.Finally,the recombinant SmPR10-1 protein was purified through Ni²⁺ affinity chromatography.The results of this study provided not only the first and fundamental information about SmPR10-1 gene,but also a candidate gene for future genetic engineering of Chinese medical herbs,S.miltiorrhiza,against pathogen attack.