Methyljasmonate Elicitation Increases Terpenoid Indole Alkaloid Accumulation in <i>Rhazya stricta</i> Hairy Root Cultures

• Main Authors: Amir Akhgari, Into Laakso, Hannu Maaheimo, Young Hae Choi, Tuulikki Seppänen-Laakso, Kirsi-Marja Oksman-Caldentey, Heiko Rischer
• Format: Article
• Language: English
• Published: MDPI AG 2019-11-01
• Series: Plants
• Subjects: <i>rhazya stricta</i>; hairy root cultures; terpenoid indole alkaloids; methyl jasmonate elicitation; chemical analyses; principal component analysis (pca)
• Online Access: https://www.mdpi.com/2223-7747/8/12/534

Methyl jasmonate is capable of initiating or improving the biosynthesis of secondary metabolites in plants and therefore has opened up a concept for the biosynthesis of valuable constituents. In this study, the effect of different doses of methyl jasmonate (MeJA) elicitation on the accumulation of terpenoid indole alkaloids (TIAs) in the hairy root cultures of the medicinal plant, <i>Rhazya stricta</i> throughout a time course (one-seven days) was investigated. Gas chromatography-mass spectrometry (GC-MS) analyses were carried out for targeted ten major non-polar alkaloids. Furthermore, overall alterations in metabolite contents in elicited and control cultures were investigated applying proton nuclear magnetic resonance (¹H NMR) spectroscopy. Methyl jasmonate caused dosage- and time course-dependent significant rise in the accumulation of TIAs as determined by GC-MS. The contents of seven alkaloids including eburenine, quebrachamine, fluorocarpamine, pleiocarpamine, tubotaiwine, tetrahydroalstonine, and ajmalicine increased compared to non-elicited cultures. However, MeJA-elicitation did not induce the accumulation of vincanine, yohimbine (isomer II), and vallesiachotamine. Furthermore, principal component analysis (PCA) of ¹H NMR metabolic profiles revealed a discrimination between elicited hairy roots and control cultures with significant increase in total vindoline-type alkaloid content and elevated levels of organic and amino acids. In addition, elicited and control samples had different sugar and fatty acid profiles, suggesting that MeJA also influences the primary metabolism of <i>R. stricta</i> hairy roots. It is evident that methyl jasmonate is applicable for elevating alkaloid accumulation in &#8220;hairy root&#8221; organ cultures of <i>R. strica.</i>