Aberrant synthesis of indole-3-acetic acid in Saccharomyces cerevisiae triggers morphogenic transition, a virulence trait of pathogenic fungi.
Many plant-associated microbes synthesize the auxin indole-3-acetic acid (IAA), and several IAA biosynthetic pathways have been identified in microbes and plants. Saccharomyces cerevisiae has previously been shown to respond to IAA by inducing pseudohyphal growth. We observed that IAA also induced hyphal growth in the human pathogen Candida albicans and thus may function as a secondary metabolite signal that regulates virulence traits such as hyphal transition in pathogenic fungi. Aldehyde dehydrogenase (Ald) is required for IAA synthesis from a tryptophan (Trp) precursor in Ustilago maydis. Mutant S. cerevisiae with deletions in two ALD genes are unable to convert radiolabeled Trp to IAA, yet produce IAA in the absence of exogenous Trp and at levels higher than wild type. These data suggest that yeast may have multiple pathways for IAA synthesis, one of which is not dependent on Trp.
Department of Biology and Biotechnology, Life Sciences and Bioengineering Center at Gateway Park, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01605, USA. rpr@wpi.edu
Reeta Prusty
RP
Rao
Ally
A
Hunter
Olga
O
Kashpur
Jennifer
J
Normanly
D002176:Candida albicans / Q000166:cytology / Q000187:drug effects; D004171:Diploidy; D017353:Gene Deletion; D005800:Genes, Fungal / Q000235:genetics; D005820:Genetic Testing; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D007210:Indoleacetic Acids / Q000737:chemistry / Q000378:metabolism*; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D009024:Morphogenesis / Q000187:drug effects; D019655:Quantitative Trait, Heritable; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity*; D014364:Tryptophan / Q000494:pharmacology; D014774:Virulence / Q000187:drug effects
D007210:Indoleacetic Acids; C030737:indoleacetic acid; D014364:Tryptophan