Enhanced production of valtrate in hairy root cultures of Valeriana jatamansi Jones by methyl jasmonate, jasmonic acid and salicylic acid elicitors

Abstract

Valtrate is a pharmacologically active epoxyiridoid ester found in the roots and rhizomes of Valeriana jatamansi Jones. The plant produces only small amounts of this metabolite naturally, and so induction of hairy roots as well as elicitation can be useful to increase its commercial production. In this study, strain R1601 of Agrobacterium rhizogenes was used to induce hairy roots in V. jatamansi, and stable hairy root cultures of V. jatamansi were established successfully. The influence of three exogenous elicitors including methyl jasmonate (MJ), jasmonic acid (JA) and salicylic acid (SA) on valtrate production in the hairy root cultures of V. jatamansi was also investigated, and the 25-day-old hairy root cultures were treated with different concentrations of the elicitors at exposure time of 7 days. This present study showed that MJ (100 mg/L) highly promoted valtrate production at 7 days after elicitation, to a level of 3.63 times higher than that of non-elicited control. SA did not significantly increase the production of valtrate. This is the first-time study to assess the elicitation of hairy root cultures to promote valtrate biosynthesis in V. jatamansi and the resulting experiments demonstrated that MJ was indeed a potent inducer of valtrate biosynthesis.

Biotic Elicitors in Adventitious and Hairy Root Cultures: A Review from 2010 to 2022

“…Elicitors are compounds that stimulate any type of plant defense, promoting secondary metabolism to protect the cell and the whole plant [25][26][27][28] since they can trigger the expression of key genes in the secondary biosynthetic pathways.…”

“…Molecules 2022, 27, 5253 2 of 26 The genes of the T-DNA which are responsible for the root development [2] are the rol genes. Among the rol genes, the most important are rol A gene which increases the sensitivity of the transformed cell to auxin [3], the rol B gene which has a role in signal transduction related to auxin sensitivity [4] as confirmed by its tyrosine phosphatase activity [5] (this rol gene is crucial for hairy root initiation and elongation, and especially, in meristem formation [6]), and the rol C gene which hydrolizes the conjugates of cytokinins [3].…”

Phytochemical Changes in Ginseng (Withania somnifera) Hairy Roots with Endophytic Fungi

“…Elicitors are compounds that can stimulate plant defense responses and boost secondary metabolite production. This helps protect the plant's cells and tissues (Zhao et al, 2020;Baenas et al, 2014). Elicitors work by activating or enhancing the expression of key genes involved in secondary metabolic pathways (Goel et al, 2011).…”