naphthoquinones and methyl-jasmonate

Alkannin/shikonin and their derivatives are specialised metabolites of high pharmaceutical and ecological importance exclusively produced in the periderm of members of the plant family Boraginaceae. Previous studies have shown that their biosynthesis is induced in response to methyl jasmonate but not salicylic acid, two phytohormones that play important roles in plant defence. However, mechanistic understanding of induction and non-induction remains largely unknown. In the present study, we generated the first comprehensive transcriptomic dataset and metabolite profiles of Lithospermum officinale plants treated with methyl jasmonate and salicylic acid to shed light on the underlying mechanisms. Our results highlight the diverse biological processes activated by both phytohormones and reveal the important regulatory role of the mevalonate pathway in alkannin/shikonin biosynthesis in L. officinale. Furthermore, by modelling a coexpression network, we uncovered structural and novel regulatory candidate genes connected to alkannin/shikonin biosynthesis. Besides providing new mechanistic insights into alkannin/shikonin biosynthesis, the generated methyl jasmonate and salicylic acid elicited expression profiles together with the coexpression networks serve as important functional genomic resources for the scientific community aiming at deepening the understanding of alkannin/shikonin biosynthesis.

Topics: Acetates; Cyclopentanes; Lithospermum; Mevalonic Acid; Naphthoquinones; Oxylipins; Pharmaceutical Preparations; Plant Growth Regulators; Salicylic Acid

Transcriptional activation of genes belonging to the plastidial MEP-derived isoprenoid pathway by elicitation with methyl jasmonate and coronatine enhanced the content of bioactive abietane diterpenes in Salvia sclarea hairy roots. We have shown that aethiopinone, an abietane diterpene synthesized in Salvia sclarea roots is cytotoxic and induces apoptosis in human melanoma cells. To develop a production platform for this compound and other abietane diterpenes, hairy root technology was combined with the elicitation of methyl jasmonate (MeJA) or the phytotoxin coronatine (Cor). Both MeJA and Cor induced a significant accumulation of aethiopinone, but prolonged exposure to MeJA irremediably caused inhibition of hairy root growth, which was unaffected by Cor treatment. Considering together the fold increase in aethiopinone content and the final hairy root biomass, the best combination was a Cor treatment for 28 days, which allowed to obtain up to 105.34 ± 2.30 mg L

Topics: Abietanes; Acetates; Amino Acids; Biomass; Cyclopentanes; Gene Expression Profiling; Gene Expression Regulation, Plant; Indenes; Naphthoquinones; Oxylipins; Plant Roots; RNA, Messenger; Salvia; Transcription, Genetic

The shikonin derivatives, accumulated in the roots of Arnebia euchroma (Boraginaceae), showed antibacterial, anti-inflammatory, and anti-tumor activities. To explore their possible biosynthesis regulation mechanism, this paper investigated the effects of exogenous methyl jasmonate (MJ) on the biosynthesis of shikonin derivatives in callus cultures of A. euchroma. The main results include: Under MJ treatment, the growth of A. euchroma callus cultures was not inhibited, but the expression level of both the genes involved in the biosynthesis of shikonin derivatives and their precursors and the genes responsible for intracellular localization of shikonin derivatives increased significantly in the Red Strain (shikonin derivatives high-producing strain). The quantitative analysis showed that six out of the seven naphthoquinone compounds under investigation increased their contents in the MJ-treated Red Strain, and in particular, the bioactive component acetylshikonin nearly doubled its content in the MJ-treated Red Strain. In addition, it was also observed that the metabolic profiling of naphthoquinone compounds changed significantly after MJ treatment, and the MJ-treated and MJ-untreated strains clearly formed distinct clusters in the score plot of PLS-DA. Our results provide some new insights into the regulation mechanism of the biosynthesis of shikonin derivatives and a possible way to increase the production of naphthoquinone compounds in A. euchroma callus cultures in the future.

Topics: Acetates; Boraginaceae; Cell Culture Techniques; Cyclopentanes; Naphthoquinones; Oxylipins; Plant Proteins; Plant Roots

Elicitation of Plumbago indica hairy roots with yeast carbohydrate fraction, chitosan, manganese chloride, copper chloride and methyl jasmonate exhibited significant elevation (~1.2 to 2 fold) of plumbagin production in shake flask culture as compared with control. Chitosan and methyl jasmonate elicitation also caused simultaneous plumbagin leaching into culture media. Three days' exposure of chitosan (200 mg l(-1)) and methyl jasmonate (80 μM) together synergized total plumbagin yield to its maximum 11.96 ± 0.76 mg g(-l) DW in shake flask culture. In bioreactor cultivation, a significant raise in fresh root biomass was recorded on day 20 as compared with control shake flask culture. Three days' exposure of chitosan (200 mg l(-1)) and methyl jasmonate (80 μM) with 20 days old bioreactor-culture significantly improved total plumbagin production to 13.16 ± 1.72 mg g(-l) DW with simultaneous plumbagin leaching into bioreactor media.

Topics: Acetates; Biomass; Bioreactors; Cell Culture Techniques; Cells, Cultured; Chitosan; Culture Media; Cyclopentanes; Fungi; Naphthoquinones; Oxylipins; Plant Roots; Plumbaginaceae

Impatiens balsamina root cultures were treated with yeast extract (YE), Candida albicans homogenate (CAH), Trichophyton rubrum homogenate (TRH), chitosan (CHI) and methyl jasmonate (MJ). Different elicitors, depending on concentrations used exerted differential effects on the production of the three main naphthoquinones, lawsone (2-hydroxy-1,4-naphthoquinone), lawsone methyl ether and methylene-3,3'-bilawsone. Treatment with MJ (400microM) was capable of increasing production of lawsone, and lawsone methyl ether up to 8.6- and 11.3-fold higher, respectively, compared to the level in untreated cultures. Treatment of 21-day-old root cultures with 300microM MJ for 36h resulted in the production of 10.0, 0.78 and 0.23mg/g DW of lawsone, its methyl ether and methylene-3,3'-bilawsone, respectively. Such levels are sufficient for commercial production.

Topics: Acetates; Cyclopentanes; Dose-Response Relationship, Drug; Impatiens; Naphthoquinones; Oxylipins; Plant Roots