Effect of NaCl Stress on Antioxidant Capacity of Lactiplantibacillus plantarum IMAUJBP3 and Transcriptome Analysis

In order to explore the changes of antioxidant performance of Lactiplantibacillus plantarum IMAIJIBP3 strain under 6.5% NaCl stress, antioxidant apparent indexes and transcriptomics of IMAUJBP3 strain were investigated. The results showed that the scavenging rates of DPPH radical and hydroxyl radical of bacterial suspension, fermentation supernatant and intracellular extract of IMAUJBP3 treated by NaCl were higher than those of the control group. However, in terms of superoxide anion clearance, the scavenging rate of bacterial suspension and fermentation supernatant treated with NaCl was higher than that of the control group, while the superoxide anion scavenging ability of intracellular extracts was significantly (P<0.05) lower than that of the control group. After NaCl treatment, the total antioxidant capacity of the strain decreased. Transcriptome analysis showed that the redox-related genes were up-regulated in glutathione-glutathione reductase system and thioredoxin-thioredoxin reductase system, while energy-related genes were mostly down-regulated the most. JBP3 adapts to NaCl stress mainly through transcription and carbohydrate transport and metabolism, regulates cell physical structure by regulating the biological process of cell and metabolism, affects catalytic activity and the binding site between rRNA and protein, and alleviates the adverse reactions of NaCl stress treatment. At the same time, it can relieve intracellular osmotic pressure by regulating anion efflux. Therefore, Lactiplantibacillus plantarum IMAUJBP3 had the function of regulating antioxidation under NaCl stress and had the potential of practical application.