Abstract: This investigation studied the expression of salt stress-related genes in Lactobacillus plantarum FS5-5, a salt-tolerance strain isolated from naturally fermented miso in northeastern China, at the level of transcription. Results showed that in the logarithmic growth phase, 29 genes were significantly down-regulated, including four ones involved in carbohydrate transport and metabolism, nine ones involved in amino acids transport and metabolism, three ones involved in vitamin metabolism, six ones involved in nucleotide metabolism and seven ones involved in genetic information translation, ribosomal structure and biogenesis. Four genes involved in carbohydrate transport and metabolism were significantly upregulated, which might be closely associated with salt stress resistance of L. plantarum FS5-5. Three genes involved in vitamin metabolism and one gene involved in nucleotide metabolism were selected to be analyzed by real-time fluorescent quantitative polymerase chain reaction and the results showed that the expression of these genes exhibited the same trend in these two methods. The comprehensive analysis of the mechanism of action of L. plantarum FS5-5 to resist salt stress presented in this study which would provide a theoretical basis to improve the tolerance of strains in industrial production.

Key words: Lactobacillus plantarum, salt stress, real-time fluorescent quantitative polymerase chain reaction; transcriptomics