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.

中文翻译：

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植物乳杆菌WCFS1对羟基酪醇反应的分子机制的转录组学证据。

摘要：这项研究旨在获得对植物乳杆菌WCFS1响应羟基酪醇（HXT）的分子机制的新见解，羟基酪醇是橄榄油中主要的与健康相关的植物酚类之一。为了达到这个目标，使用了全基因组转录组谱分析来更好地理解差异基因表达在这种微生物对HXT的适应中的作用。转录组图谱揭示了HXT触发的抗氧化反应，涉及来自植物乳杆菌ROS（活性氧物种）抵抗组的基因，编码产生H2S的酶的基因以及参与对硫醇特异性氧化应激反应的基因。与细胞壁生物发生有关的一组基因的表达也被上调，表明该亚细胞区室是HXT的靶标。几种MFS（主要促进子超家族）外排系统和ABC转运蛋白的表达受HXT的影响不同，可能是为了控制其跨膜转运。植物乳杆菌通过转录重新编程氮代谢，并涉及严格的应答（SR）以适应HXT，这与参与细胞增殖或与触发SR的分子（p）ppGpp的代谢有关的基因表达减少所表明。我们的数据已在基因组规模上确定了HXT作用的抗菌机制以及可能使植物乳杆菌应对这种酚类化合物的作用的分子机制。植物转录转录重新编程的氮代谢并涉及严格应答（SR）以适应HXT，这与参与细胞增殖或与触发SR的分子（p）ppGpp的代谢有关的基因表达减少所表明。我们的数据已在基因组规模上确定了HXT作用的抗菌机制以及可能使植物乳杆菌应对这种酚类化合物的影响的分子机制。植物转录转录重新编程的氮代谢并涉及严格应答（SR）以适应HXT，这与参与细胞增殖或与触发SR的分子（p）ppGpp的代谢有关的基因表达减少所表明。我们的数据已在基因组规模上确定了HXT作用的抗菌机制以及可能使植物乳杆菌应对这种酚类化合物的影响的分子机制。