Callus induction and withanolides production through cell suspension culture of <i>Withania coagulans</i> (Stocks) Dunal

Withania coagulans (Stocks) Dunal is a well-known medicinal plant due to its many healing properties.

The aim of the present study was to induce friable callus and subsequently establish the plant cell suspension cultures for the production of two important withanolides i.e. withaferin A (WFA) and withanolide A (WNA).

In vitro callus induction was carried out from young leaf and internodal explants cultured on MS medium fortified with various concentrations (0, 1.0, 1.5, 2.0 and 2.5 mg/L) of auxins (2,4-D, NAA, and IAA) solely or in combination with BAP (0., 0.5 and 1.0 mg/L) in a factorial experiment based on a completely randomized design with five replications. The plant cell culture was then established for the production of both withanolides.

The percentage of callogenesis from the leaf (25.0-96.0 %) was higher than internodal explants (23.2-85.4 %). The high percentage of friable calli was achieved from leaf explants cultured on MS medium fortified with 2.5 mg/L 2,4-D + 0.5 mg/L BAP. Cell suspension culture was established from derived friable callus cultured on MS medium supplemented with 1.5 mg/L IAA + 0.5 mg/L BAP. The highest accumulation of biomass (172 g/L fresh weight and 15 g/L dry weight) and the production of both withanolides were observed in the fourth week of the culture period. The plant cells produced 0.08 and 21 µg/L WFA and WNA at this time, respectively.

These results can be used for future research on biosynthesis pathways of withanolides as well as their production in bioreactors.