Fungal elicitor-mediated enhancement in phenylpropanoid and naphtodianthrone contents of Hypericum perforatum L. cell cultures

Abstract

Hypericum perforatum cell suspensions were evaluated for their growth, phenylpropanoid and naphtodianthrone productions, and antioxidant activity after treatments with fungal elicitors Fusarium oxysporum, Phoma exigua and Botrytis cinerea. Elicited cells displayed a reduced biomass production, a rapid stimulation of secondary metabolites production and a modification of cell redox state compared to control. Cells responded strongly towards the applied elicitors through the enhanced production of naphtodianthrones. Hypericin and pseudohypericin production was significantly increased (up to fourfold) in the early growth phase and remained stable all along the post-elicitation period. Significant increase in contents of total phenolics, total flavonoids and total anthocyanins was observed during the entire period of cultivation, while total flavanols were enhanced at the end of post-elicitation. The enzymatic activities of phenylalanine ammonia lyase and chalcone isomerase were remarkably elevated in elicited cells confirming a strong activation of phenylpropanoid/flavonoid pathways. The fingerprint profile of Fourier transform infrared spectroscopy spectra from the cell walls showed a little variation in lignin accumulation between elicited and control samples. With regards to the antioxidant state, an early up-regulation of peroxidase activity was observed in elicited cells, whereas non-enzymatic properties and catalase activity were enhanced at the end of post-elicitation. These findings suggest the involvement of an efficient antioxidant defense system in the adaptive response of cells to fungal elicitation. Altogether, these results indicated that H. perforatum elicited cells represent a promising experimental system for scaleup production of naphtodianthrones for medicinal uses.

Ephedrine production from suspension cultures of Ephedra alata L. callus

“…Mendhulkar and Vakil (2013) hypothesized the elicitation mechanism as the binding of the elicitor to plasma membrane receptors, which initiates signaling processes that activate plant defense. Fungal elicitors have been widely used to increase the accumulation of natural products in plant cell cultures, and this strategy has been effective in stimulating the production of many chemical classes of secondary metabolites such as alkaloids (Taha et al, 2009), phenolics, flavonoids, anthocyanins Gadzovska et al, 2015), and glucosides (Nadeem et al, 2018). In the present study, the A. niger extract was found to be useful for the enhancement of ephedrine accumulation.…”

“…Mendhulkar and Vakil (2013) also reported a significant increase in flavonoid accumulation in suspension cultures of Andrographis paniculata after elicitation with an A. niger extract. Moreover, Gadzovska et al (2015) observed a significant increase in naphtodianthrones, total phenolics, flavonoids, and anthocyanins in Hypericum perforatum cell suspensions treated with A. niger extract. However, as reported in the present study, increasing the concentration of A. niger extract showed less ephedrine accumulation.…”

“…Aspergillus niger extract also increased the synthesis of psoralen in cell cultures of Psoralea corylifolia (Ahmed and Baig, 2014). Gadzovska et al (2015) reported a significant increase in naphtodianthrones, total phenolics, flavonoids, and anthocyanins in Hypericum perforatum cell suspensions by adding A. niger extract. Yeast extract application improved the production of stilbenes in Cayratia trifolia (Roat and Ramawat, 2009).…”

“…The advantage of this method is that it can ultimately provide a continuous, reliable source of natural products, thus avoiding the limited availability and complexity of chemical synthesis or extraction from whole plants. Suspension culture has been effectively utilized commercially for the production of valuable secondary metabolites such as taxol, resveratrol, naphtodianthrones, total phenolics, flavonoids, anthocyanins, artemisinin, ginsenosides, and ajmalicine (Xu et al, 2011;Gadzovska et al, 2015;Gonçalves and Romano, 2018). In recent years, suspension culture is viewed as an alternative to traditional agriculture for the industrial production of plant secondary metabolites (Yue et al, 2014).…”

“…However, it is well known that elicitors activate signaling pathways and transcription factors, which leads to the production of secondary metabolites in plants (Schluttenhofer and Yuan, 2015). Aspergillus niger and yeast extract are among the most effective elicitors in enhancing the production of valuable secondary metabolites in vitro, especially alkaloids (Roat and Ramawat, 2009;Taha et al, 2009;Udomsuk et al, 2011;Mendhulkar and Vakil, 2013;Pirian and Piri, 2013;Vakil and Mendhulkar, 2013;Ahmed and Baig, 2014;Gadzovska et al, 2015;Nadeem et al, 2018). Therefore, in the present study, two biotic elicitors, namely A. niger and yeast extract, were screened for the enhancement of ephedrine accumulation in suspension cultures of E. alata.…”