Study of the antibacterial properties of antimicrobial peptide MOp2 from Moringa oleifera seeds against S. aureus through transcriptomic techniques

Abstract

In the previous study, the potential antibacterial targets of peptide MOp2 from Moringa oleifera seeds against Staphylococcus aureus were analyzed at the proteomic level, but its antibacterial mechanisms were not fully elucidated. Therefore, the present study aimed to investigate the antibacterial properties of MOp2 against S. aureus. A total of 579 genes were up-regulated, and 564 genes were down-regulated in S. aureus after treatment with MOp2. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed that these differentially expressed genes were related to cell membrane permeability, pH homeostasis, energy metabolism, cell wall synthesis, and protein folding. The enzymatic activity assays confirmed the down-regulation of lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), and ATPase, which significantly disrupted the pH homeostasis and energy metabolism. Furthermore, the validation of RNA-Seq data by RT-qPCR revealed that the expression of sdhC and dnaK was down-regulated, whereas the expression of opuC, adhE, arc, and murA was up-regulated. Among these, dnaK was the key gene regulating the expression of the protein target DnaK to inhibit the growth of S. aureus. These findings complemented the antibacterial mechanism of MOp2 at the transcriptomic level, providing a theoretical basis for promoting the application of AMPs as novel preservatives.