Metabolite Production in Alkanna tinctoria Links Plant Development with the Recruitment of Individual Members of Microbiome Thriving at the Root-Soil Interface

Abstract

Previous studies have shown that individual, isolated microorganisms may influence secondary metabolism of plants and induce or stimulate the production of medicinally relevant secondary metabolism. Here, we analyzed the microbiome-metabolome linkage of the medicinal plant Alkanna tinctoria , which is known to produce valuable compounds, particularly the naphthoquinones alkannin and shikonin and their derivatives.

Root-associated bacterial communities and root metabolite composition are linked to nitrogen use efficiency in sorghum

“…Under conditions of biotic stress, the idea of a “cry for help” has been discussed as a way in which plants deploy metabolite signals to recruit beneficial microbes to help alleviate both abiotic and biotic stresses ( 24 – 27 ). While much of the research enumerating examples of the “cry for help” hypothesis has measured root exudates, root metabolites also provide an important factor in shaping microbial communities ( 28 – 30 ).…”

Root associated bacterial communities and root metabolite composition are linked to nitrogen use efficiency in sorghum

“…Under conditions of biotic stress the idea of a “cry for help” has been discussed as a way in which plants deploy metabolite signals to recruit beneficial microbes to help alleviate both abiotic and biotic stresses (Dicke & Baldwin, 2010; Liu et al, 2021; Rizaludin et al, 2021; Rolfe et al, 2019). While much of the research enumerating examples of the “cry for help” hypothesis has measured root exudates – root metabolites also provide an important factor in shaping microbial communities (Bourceret et al, 2022; Csorba et al, 2022; DeWolf et al, 2022).…”

Microbial fortification of pharmacological metabolites in medicinal plants

“…(French marigold) [76] Alkannin/shikonin Labrys Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium Penicillium (fungus) Roots Alkanna tinctoria L . [77] * Alkannin/shikonin Chitinophaga sp. Allorhizobium sp.…”

“…The roots of Alkanna tinctoria L. are rich in alkannin and shikonin, which are two enantiomeric polyphenols that induce excellent cytotoxicity in cancer cells [77] . A recent study of A. tinctoria grown in a greenhouse revealed that the plant developmental stage influenced both the metabolite contents and the plant root microbial diversity, and that the bacterial genera Labrys and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium as well as four species of the fungal genus Penicillium were positively correlated with higher contents of alkannin and shikonin [77] .…”

“…The roots of Alkanna tinctoria L. are rich in alkannin and shikonin, which are two enantiomeric polyphenols that induce excellent cytotoxicity in cancer cells [77] . A recent study of A. tinctoria grown in a greenhouse revealed that the plant developmental stage influenced both the metabolite contents and the plant root microbial diversity, and that the bacterial genera Labrys and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium as well as four species of the fungal genus Penicillium were positively correlated with higher contents of alkannin and shikonin [77] . Four bacteria strains from the root microbiome of wild A. tinctoria , including Chitinophaga sp., Allorhizobium sp., Duganella sp., and Micromonospora sp., were shown to significantly increase the contents of alkannin and shikonin in hairy roots culture of the same plant species [78] .…”