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Anchusa officinalis (L.) interacts with various microorganisms including arbuscular myc-orrhizal fungi (AMF). Recently, the AMF Rhizophagus irregularis MUCL 41833 has been shown to modulate the metabolome of A. officinalis. However, little information is available on the impact that different AMF species may have on primary and secondary plant metabolites. In this study, four AMF species belonging to the genus Rhizophagus (R. irregularis MUCL 41833, R. intraradices MUCL 49410, R. clarus MUCL 46238, R. aggregatus MUCL 49408), were evaluated for their potential to modulate A. officinalis metabolome under controlled semi-hydroponic cultivation conditions. An untargeted metabolomic analysis was performed using UHPLC-HRMS followed by a multivariate data analysis. Forty-two compounds were reported to be highly modulated in relation to the different AMF associations. Among them, six new secondary metabolites were tentatively identified including two acetyl-and four malonyl-phenylpropanoid and saponin derivatives, all presenting a common substitution at position C-6 of the glycosidic moiety. In addition, an enhanced accumulation of primary and secondary metabolites was observed for R. irregularis and R. intraradices, showing a stronger effect on A. officinalis metabolome compared to R. clarus and R. aggregatus. Therefore, our data suggest that different AMF species may specifically modulate A. officinalis metabolite production. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

Plants are naturally associated with diverse microbial communities, which play significant roles in plant performance, such as growth promotion or fending off pathogens. The roots of Alkanna tinctoria L. are rich in naphthoquinones, particularly the medicinally used enantiomers alkannin and shikonin and their derivatives. Former studies already have shown that microorganisms may modulate plant metabolism. To further investigate the potential interaction between A. tinctoria and associated microorganisms, we performed a greenhouse experiment in which A. tinctoria plants were grown in the presence of three distinct soil microbiomes. At four defined plant developmental stages, we made an in-depth assessment of bacterial and fungal root-associated microbiomes as well as all extracted primary and secondary metabolite content of root material. Our results showed that the plant developmental stage was the most important driver influencing the plant metabolite content, revealing peak contents of alkannin/shikonin derivatives at the fruiting stage. Plant root microbial diversity was influenced both by bulk soil origin and to a small extent by the developmental stage. The performed correlation analyses and cooccurrence networks on the measured metabolite content and the abundance of individual bacterial and fungal taxa suggested a dynamic and at times positive or negative relationship between root-associated microorganisms and root metabolism. In particular, the bacterial genera Labrys and Allorhizobium-Neorhizobium-Pararhizobium- Rhizobium as well as four species of the fungal genus Penicillium were found to be positively correlated with higher content of alkannins. © 2022 Csorba et al.

The present study describes the peculiar phytochemical characteristics of bergamots cultivated in distinct islands of the Ionian Sea. Ultrahigh-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS) supported by 1 and 2D NMR spectroscopy was used for unambiguous metabolic profiling of albedo, flavedo and juice samples. Profile differences were determined using a multi-analytical clustering approach based on high-performance thin-layer chromatography fingerprints and UHPLC-HRMS data. Finally, a validated HPLC method offering good precision (0.12–0.94%) and accuracy (95.25–103.93%) was proposed for the quantification of the major flavanones. A total of 37 secondary metabolites were characterized belonging to flavonoids, limonoids and coumarins. Their distribution was tissue-dependent and varied significantly from bergamots of other geographical locations. Surprisingly, neoeriocitrin was the major flavanone, reaching 1.69 ± 0.05 g/L in the juice and 5.24 ± 0.12 mg/g in albedo. This is the highest reported amount among Citrus species, rendering Ionian bergamots a promising candidate for novel functional products. © 2020 Elsevier Ltd

Arbuscular mycorrhizal fungi (AMF) are biotrophe microorganisms that establish a symbiotic association with host-plants. These plant-dependent microorganisms have already shown their strong effects concerning plant growth promotion and were reported to stimulate the secondary metabolites (SM) production of their host-plant. In this study, Anchusa officinalis plants, well-known for their therapeutic properties, were analyzed to assess the AMF effects on SM production. Two different experiments were developed on a semi-hydroponic system to compare treated A. officinalis plants with different AMF. In the first investigation, plants were inoculated with Rhizophagus irregularis, cultivated for 30 days and harvested two times. Concerning the second experiment, four different strains of AMF (R. clarus, R. intraradices, R. irregularis and Glomus aggretum) were tested separately on plants and one sampling was performed after one week. Roots and shoots were separated, lyophilized, ground and extracted using ultrasounds with EtOAc and MeOH (35:65 v/v) at 25°C. After centrifugation, the supernatants were removed and evaporated to dryness. Samples were analyzed with UHPLC-HRMS as well as HPTLC and HPLC-DAD-ELSD. Preliminary results of a targeted metabolomic analysis, showed that the concentration of main compound, rosmarinic acid, present in all the treated plants had no statistically difference from the controls. However, a discernable up-regulation and down-regulation of specific minor SMs in colonized plants was observed, suggesting that the aforementioned AMF affect specific biosynthetic pathways. Further experiments and analyses is needed but the cultivation of medicinal plants with AMF looks a promising way to enhance bioactive metabolites with applications in pharmaceutical and cosmeceutical industry.

info:eu-repo/semantics/nonPublished