Effects of Polysaccharide Elicitors from Endophytic Fusarium oxysporium Dzf17 on Growth and Diosgenin Production in Cell Suspension Culture of Dioscorea zingiberensis

Abstract

Three polysaccharides, namely exopolysaccharide (EPS), water-extracted mycelial polysaccharide (WPS) and sodium hydroxide-extracted mycelial polysaccharide (SPS), were prepared from the endophytic fungus Fusarium oxysporium Dzf17 isolated from the rhizomes of Dioscorea zingiberensis. The effects of the time of addition and polysaccharide concentration on the growth and diosgenin accumulation in cell suspension culture of D. zingiberensis were studied. Among them, WPS was found to be the most effective polysaccharide. When WPS was added to the medium at 20 mg/L on the 25th day of culture, the cell dry weight was increased 1.34-fold, diosgenin content 2.85-fold, and diosgenin yield 3.83-fold in comparison to those of control. EPS and SPS showed moderate and relatively weak enhancement effects on cell growth and diosgenin accumulation, respectively. The dynamics of cell growth and diosgenin accumulation when WPS was added to the medium at 20 mg/L on the 25th day of culture were investigated, and results showed that dry weight of cells reached a maximum value on day 30 but the maximum diosgenin content was achieved on day 31.

Plant Bioactive Metabolites and Drugs Produced by Endophytic Fungi of Spermatophyta

“…In vitro cell culturing represents an alternative means for production of this drug, considering that natural populations of one of the most important sources, the yellow ginger (Dioscorea zingiberensis), are decreasing due to overexploitation, and agricultural production is problematic by reason of the 3-4 years required for obtaining mature rhizomes. Oligosaccharides and polysaccharides extracted from an endophytic strain (Dzf17) of F. oxysporium have been found to elicit growth and diosgenin production in cell cultures of D. zingiberensis [361,362]. The same effect was also observed when both cell cultures and seedlings were treated with beauvericin produced by an endophytic strain of Fusarium redolens from the same plant species [363].…”

“…This latter undesired aspect, which is reported to impair an efficient employment of endophytic fungi by the pharmaceutical industry, might also be consequential to more subtle events at the gene level, considering that the plant-endophyte interaction may involve promotion of gene transcriptions. Coherent with this possibility are the elicitating properties observed by endophytes on the synthesis of a number of bioactive plant products, with a few cases previously mentioned in this review [193,361,362]. Finally, an intriguing elicitating function may also characterize other cohabiting endophytic strains not directly capable to produce a given metabolite, as shown in the case of strains of Alternaria sp.…”

Production and structural elucidation of exopolysaccharide from endophytic Pestalotiopsis sp. BC55

“…Since the 'billion dollar' bioactive compound paclitaxel (taxol) discovered from the endophytic fungus Taxomyces andreanae in 1993 [7], many scientists have increasing their interest in studying fungal endophytes as potential producers of novel biologically active compounds. But, in the literature, very little documentation were exists regarding EPS production from fungal endophytes [9][10][11][12][13].…”

Enhancement of Diosgenin Production in Plantlet and Cell Cultures of <i>Dioscorea zingiberensis</i> by Palmarumycin C₁₃ from the Endophytic fungus, <i>Berkleasmium </i>sp. Dzf12

“…The calli were subcultured every 30 days on Murashige and Skoog (MS) medium supplemented with 6-benzyladenine (1.5 mg/L), naphthalene acetic acid (1.0 mg/L), agar (8 g/L), and sucrose (30 g/L) in darkness [15]. The medium pH was adjusted to 5.8 before autoclaving for 15 min at 121 °C.…”