title: Indole-3-acetic acid biosynthetic pathways in the basidiomycetous yeast Rhodosporidium paludigenum.
abstract: Microorganisms produce plant growth regulators, such as auxins, cytokinins and gibberellins, to promote plant growth. Auxins are a group of compounds with an indole ring that have a positive effect on plant growth. Indole-3-acetic acid (IAA) is a plant growth hormone classified as an indole derivative of the auxin family. IAA biosynthesis pathways have been reported and widely studied in several groups of bacteria. Only a few studies on IAA biosynthesis pathways have been conducted in yeast. This study aimed to investigate IAA biosynthesis pathways in a basidiomycetous yeast (Rhodosporidium paludigenum DMKU-RP301). Investigations were performed both with and without a tryptophan supplement. Indole compound intermediates were detected by gas chromatography-mass spectrometry. Indole-3-lactic acid and indole-3-ethanol were found as a result of the enzymatic reduction of indole-3-pyruvic acid and indole-3-acetaldehyde, in IAA biosynthesis via an indole-3-pyruvic acid pathway. In addition, we also found indole-3-pyruvic acid in culture supernatants determined by high-performance liquid chromatography. Identification of tryptophan aminotransferase activity supports indole-3-pyruvic acid-routed IAA biosynthesis in R. paludigenum DMKU-RP301. We hence concluded that R. paludigenum DMKU-RP301 produces IAA through an indole-3-pyruvic acid pathway.
authors.affiliation: Department of Microbiology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.|Center for Advanced Studies in Tropical Natural Resources, NRU-KU, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.
authors.forename: Pumin
authors.initials: P
authors.lastname: Nutaratat
authors.affiliation: Department of Microbiology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand. fscints@ku.ac.th.|Center for Advanced Studies in Tropical Natural Resources, NRU-KU, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand. fscints@ku.ac.th.
authors.forename: Nantana
authors.initials: N
authors.lastname: Srisuk
authors.affiliation: Department of Chemistry, Faculty of Science, Srinakharinwirot University, Bangkok, 10110, Thailand.
authors.forename: Panarat
authors.initials: P
authors.lastname: Arunrattiyakorn
authors.affiliation: Department of Microbiology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.|Center for Advanced Studies in Tropical Natural Resources, NRU-KU, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.
authors.forename: Savitree
authors.initials: S
authors.lastname: Limtong
mesh_terms: D001487:Basidiomycota / Q000378:metabolism / Q000502:physiology*; D053898:Biosynthetic Pathways; D008401:Gas Chromatography-Mass Spectrometry; D007210:Indoleacetic Acids / Q000032:analysis / Q000378:metabolism*; D007211:Indoles / Q000032:analysis / Q000378:metabolism; D010937:Plant Growth Regulators / Q000096:biosynthesis*; D014364:Tryptophan / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D007211:Indoles; D010937:Plant Growth Regulators; C030737:indoleacetic acid; D014364:Tryptophan
keywords: Basidiomycetous yeast; Biosynthetic pathway; Indole-3-acetic acid; Red yeast; Rhodosporidium