Chitosan enhances withanolides production in adventitious root cultures of Withania somnifera (L.) Dunal

Abstract

Calli were obtained from leaf, cotyledon and internode explants of in vitro-grown plants of Indian cultivar of Withania somnifera in MS medium supplemented with 2, 4-D (2.0mgl−1) and Kinetin (0.2mgl−1). The brown, semi-friable callus (500mg FW) derived from leaf explants produced higher number of primary adventitious roots (9 roots/callus) in half strength MS medium fortified with IBA (0.5mgl−1) and NAA (0.1mgl−1). The primary adventitious roots with an inoculum mass of 15g FW were cultured for 6 weeks in the same medium for secondary adventitious root proliferation. Elicitation of abiotic elicitor, aluminium chloride at 10mgl−1 at the end of 4 weeks culture with 4h exposure time enhanced withanolides productivity. Under similar culture conditions, the biotic elicitor, chitosan at 100mgl−1 stimulated higher production of all withanolides when compared to aluminium chloride treatment. This is the first report on the use of callus-derived adventitious root culture for the enhanced production of withanolides upon chitosan elicitation.