title: Fungal endophytes of Catharanthus roseus enhance vindoline content by modulating structural and regulatory genes related to terpenoid indole alkaloid biosynthesis.
abstract: Not much is known about the mechanism of endophyte-mediated induction of secondary metabolite production in Catharanthus roseus. In the present study two fungal endophytes, Curvularia sp. CATDLF5 and Choanephora infundibulifera CATDLF6 were isolated from the leaves of the plant that were found to enhance vindoline content by 229-403%. The isolated endophytes did not affect the primary metabolism of the plant as the maximum quantum efficiency of PSII, net CO2 assimilation, plant biomass and starch content of endophyte-inoculated plants was similar to endophyte-free control plants. Expression of terpenoid indole alkaloid (TIA) pathway genes, geraniol 10-hydroxylase (G10H), tryptophan decarboxylase (TDC), strictosidine synthase (STR), 16-hydoxytabersonine-O-methyltransferase (16OMT), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT) were upregulated in endophyte-inoculated plants. Endophyte inoculation upregulated the expression of the gene for transcriptional activator octadecanoid-responsive Catharanthus AP2-domain protein (ORCA3) and downregulated the expression of Cys2/His2-type zinc finger protein family transcriptional repressors (ZCTs). The gene for the vacuolar class III peroxidase (PRX1), responsible for coupling vindoline and catharanthine, was upregulated in endophyte-inoculated plants. These endophytes may enhance vindoline production by modulating the expression of key structural and regulatory genes of vindoline biosynthesis without affecting the primary metabolism of the host plant.
authors.affiliation: Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow-226015, India.
authors.forename: Shiv S
authors.initials: SS
authors.lastname: Pandey
authors.affiliation: Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow-226015, India.
authors.forename: Sucheta
authors.initials: S
authors.lastname: Singh
authors.affiliation: CSIR-Central Institute of Medicinal and Aromatic Plants, Research Centre, Allalasandra, GKVK Post, Bangalore-560065, India.
authors.forename: C S Vivek
authors.initials: CS
authors.lastname: Babu
authors.affiliation: Analytical Chemistry Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow-226015, India.
authors.forename: Karuna
authors.initials: K
authors.lastname: Shanker
authors.affiliation: Plant Physiology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow-226015, India.
authors.forename: N K
authors.initials: NK
authors.lastname: Srivastava
authors.affiliation: Biotechnology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow-226015, India.
authors.forename: Ashutosh K
authors.initials: AK
authors.lastname: Shukla
authors.affiliation: Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow-226015, India.
authors.forename: Alok
authors.initials: A
authors.lastname: Kalra
mesh_terms: D030008:Catharanthus / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D060026:Endophytes / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D009090:Mucorales / Q000254:growth & development*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D014747:Vinblastine / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: C009667:vindoline; D014747:Vinblastine