Transcriptomic Evidence of Molecular Mechanisms Underlying the Response of Lactobacillus plantarum WCFS1 to Hydroxytyrosol

Abstract

This study was aimed to gain new insights into the molecular mechanisms used by Lactobacillus plantarum WCFS1 to respond to hydroxytyrosol (HXT), one of the main and health-relevant plant phenolics present in olive oil. To this goal, whole genome transcriptomic profiling was used to better understand the contribution of differential gene expression in the adaptation to HXT by this microorganism. The transcriptomic profile reveals an HXT-triggered antioxidant response involving genes from the ROS (reactive oxygen species) resistome of L. plantarum, genes coding for H2S-producing enzymes and genes involved in the response to thiol-specific oxidative stress. The expression of a set of genes involved in cell wall biogenesis was also upregulated, indicating that this subcellular compartment was a target of HXT. The expression of several MFS (major facilitator superfamily) efflux systems and ABC-transporters was differentially affected by HXT, probably to control its transport across the membrane. L. plantarum transcriptionally reprogrammed nitrogen metabolism and involved the stringent response (SR) to adapt to HXT, as indicated by the reduced expression of genes involved in cell proliferation or related to the metabolism of (p)ppGpp, the molecule that triggers the SR. Our data have identified, at genome scale, the antimicrobial mechanisms of HXT action as well as molecular mechanisms that potentially enable L. plantarum to cope with the effects of this phenolic compound.

Phenolic-Rich Plant Extracts With Antimicrobial Activity: An Alternative to Food Preservatives and Biocides?

“…Lactobacillus plantarum -upregulation of antioxidant response involving genes from the reactive oxygen species resistome of Lb. plantarum, genes coding for H 2 S-producing enzymes and genes involved in the response to thiol-specific oxidative stress -upregulation of a set of genes involved in cell wall biogenesis Reverón et al, 2020 Gallic acid, protocatechuic acid and vanillic acid…”

“…Nevertheless, multiplication in recent years of studies by -omics approaches opens the possibility to identify new mechanisms of action or to identify several mechanisms of action acting simultaneously (which is generally the case at least for plant extracts and even for some pure plant phenolics). Transcriptomics ( Alvarado-Martinez et al, 2020 ; Linzner et al, 2020 ; Reverón et al, 2020 ), proteomics ( Ozdemir and Soyer, 2020 ) and metabolomics ( Wu et al, 2020 ) approaches recently contributed to the identification of targets of antimicrobial action of some plant phenolics or phenolic-rich plant extracts. Transcriptomic ( Reverón et al, 2020 ) and metabolomic ( Wu et al, 2020 ) analyses allow to identify which metabolic pathways are affected by plant phenolics.…”

“…Transcriptomics ( Alvarado-Martinez et al, 2020 ; Linzner et al, 2020 ; Reverón et al, 2020 ), proteomics ( Ozdemir and Soyer, 2020 ) and metabolomics ( Wu et al, 2020 ) approaches recently contributed to the identification of targets of antimicrobial action of some plant phenolics or phenolic-rich plant extracts. Transcriptomic ( Reverón et al, 2020 ) and metabolomic ( Wu et al, 2020 ) analyses allow to identify which metabolic pathways are affected by plant phenolics.…”

Molecular Responses of Lactobacilli to Plant Phenolic Compounds: A Comparative Review of the Mechanisms Involved

“…Several studies have addressed the transcriptomic responses of Lactobacillus spp. to individual PPCs [ 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. The transcriptomes of the model strain Lactiplantibacillus plantarum WCFS1 exposed to different representative PPCs, including a hydroxycinnamic acid ( p -coumaric acid ( p -CA)) [ 25 ], a hydroxybenzoic acid (gallic acid (GA)) [ 26 ], a stilbene (resveratrol (RSV)) [ 27 ], a secoiridoid (oleuropein (OLE)) [ 28 ], and a phenylethanoid (hydroxytyrosol (HXT)) [ 29 ] have been revealed using DNA microarrays.…”

“…to individual PPCs [ 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. The transcriptomes of the model strain Lactiplantibacillus plantarum WCFS1 exposed to different representative PPCs, including a hydroxycinnamic acid ( p -coumaric acid ( p -CA)) [ 25 ], a hydroxybenzoic acid (gallic acid (GA)) [ 26 ], a stilbene (resveratrol (RSV)) [ 27 ], a secoiridoid (oleuropein (OLE)) [ 28 ], and a phenylethanoid (hydroxytyrosol (HXT)) [ 29 ] have been revealed using DNA microarrays. The standardized experimental setup, applying stresses for 10 min to the same strain, permitted a reliable comparison among the different responses to these PPCs.…”