title: Endophytes are hidden producers of maytansine in Putterlickia roots.
abstract: Several recent studies have lent evidence to the fact that certain so-called plant metabolites are actually biosynthesized by associated microorganisms. In this work, we show that the original source organism(s) responsible for the biosynthesis of the important anticancer and cytotoxic compound maytansine is the endophytic bacterial community harbored specifically within the roots of Putterlickia verrucosa and P. retrospinosa plants. Evaluation of the root endophytic community by chemical characterization of their fermentation products using HPLC-HRMS(n), along with a selective microbiological assay using the maytansine-sensitive type strain Hamigera avellanea revealed the endophytic production of maytansine. This was further confirmed by the presence of AHBA synthase genes in the root endophytic communities. Finally, MALDI-imaging-HRMS was used to demonstrate that maytansine produced by the endophytes is typically accumulated mainly in the root cortex of both plants. Our study, thus, reveals that maytansine is actually a biosynthetic product of root-associated endophytic microorganisms. The knowledge gained from this study provides fundamental insights on the biosynthesis of so-called plant metabolites by endophytes residing in distinct ecological niches.
authors.affiliation: Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund , Otto-Hahn-Straße 6, D-44221 Dortmund, Germany.
authors.forename: Souvik
authors.initials: S
authors.lastname: Kusari
authors.forename: Marc
authors.initials: M
authors.lastname: Lamshöft
authors.forename: Parijat
authors.initials: P
authors.lastname: Kusari
authors.forename: Sebastian
authors.initials: S
authors.lastname: Gottfried
authors.forename: Sebastian
authors.initials: S
authors.lastname: Zühlke
authors.forename: Kathrin
authors.initials: K
authors.lastname: Louven
authors.forename: Ute
authors.initials: U
authors.lastname: Hentschel
authors.forename: Oliver
authors.initials: O
authors.lastname: Kayser
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
mesh_terms: D062365:Aminobenzoates / Q000378:metabolism; D029753:Celastraceae / Q000378:metabolism / Q000382:microbiology; D002851:Chromatography, High Pressure Liquid; D060026:Endophytes / Q000737:chemistry* / Q000378:metabolism; D006836:Hydro-Lyases / Q000378:metabolism*; D062385:Hydroxybenzoates / Q000378:metabolism; D008453:Maytansine / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D062365:Aminobenzoates; D062385:Hydroxybenzoates; D008453:Maytansine; C031509:3-amino-5-hydroxybenzoic acid; C111160:3-amino-5-hydroxybenzoic acid synthase; D006836:Hydro-Lyases