Arbuscular mycorrhizal fungi altered the hypericin, pseudohypericin, and hyperforin content in flowers of Hypericum perforatum grown under contrasting P availability in a highly organic substrate

Abstract

St. John's Wort (Hypericum perforatum) is a perennial herb able to produce water-soluble active ingredients (a.i.), mostly in flowers, with a wide range of medicinal and biotechnological uses. However, information about the ability of arbuscular mycorrhizal fungi (AMF) to affect its biomass accumulation, flower production, and concentration of a.i. under contrasting nutrient availability is still scarce. In the present experiment, we evaluated the role of AMF on growth, flower production, and concentration of bioactive secondary metabolites (hypericin, pseudohypericin, and hyperforin) of H. perforatum under contrasting P availability. AMF stimulated the production of aboveground biomass under low P conditions and increased the production of root biomass. AMF almost halved the number of flowers per plant by means of a reduction of the number of flower-bearing stems per plant under high P availability and through a lower number of flowers per stem in the low-P treatment. Flower hyperforin concentration was 17.5% lower in mycorrhizal than in non-mycorrhizal plants. On the contrary, pseudohypericin and hypericin concentrations increased by 166.8 and 279.2%, respectively, with AMF under low P availability, whereas no effect of AMF was found under high P availability. These results have implications for modulating the secondary metabolite production of H. perforatum. However, further studies are needed to evaluate the competition for photosynthates between AMF and flowers at different nutrient availabilities for both plant and AM fungus.

Production of biomolecules of interest to the anxiolytic herbal medicine industry in yellow passionfruit leaves (Passiflora edulis f. flavicarpa) promoted by mycorrhizal inoculation

“…26 Nonetheless, other mechanisms can be acting together, as suggested by Mechri et al 27 via higher activation of metabolic pathways, 28 gene expression of key-enzymes, 29 and higher absorption of nutrients. 30 Increases of 33%, 58%, and 29% were recorded for the aerial part fresh matter, aerial part dry matter, and leaf area, respectively, when plants of P. edulis were inoculated with A. longula in relation to control plants ( Table 1). The remaining classic growth parameters presented no increase ( Table 2).…”

“…Nonetheless, other mechanisms can be acting together, as suggested by Mechri et al . via higher activation of metabolic pathways, gene expression of key‐enzymes, and higher absorption of nutrients …”

Variability of Hypericins and Hyperforin in Hypericum Species from the Sicilian Flora

“…Other works have taken into account some aspects of cropping management concerned with the hypericins content of dry herbage . However, since so many aspects are involved in hyperforin and hypericins production and storage inside the plants, it appears that further efforts must be addressed to a deeper insight about the best agricultural practices to apply for improving yield and quality aspects of Hypericum under cultivation.…”

“…In USA, market indices about pricing of H. perforatum herb agree on the conclusion that Hypericum field production may allow gaining 2.000 to 3.000 $/acre, provided the harvested biomass is rich in hypericin . Hence, great efforts are addressed to improve field management techniques, with the goal to enhance the yield of those phytochemicals that are thought to be responsible for the therapeutic properties of the plant …”

Arbuscular Mycorrhizal Fungi Regulate Flowering of Hyacinths orientalis L. Anna Marie

“…Mycorrhizal inoculation markedly increased flower height of C. morifolium (Vaingankar and Rodrigues, 2012) or had no significant effect (Linderman and Davis, 2004). AMF also enhanced the number of flowers of snapdragon and Hypericum perforatum (Asrar et al, 2012;Lazzara et al, 2017) or had no effect on it (Mora, 1990). It concludes that AMF can potentially improve flower morphology, heavily depended on the compatibility of both AMF and host plants, which is still needed to be considered in future.…”