title: Perturbation of Arabidopsis amino acid metabolism causes incompatibility with the adapted biotrophic pathogen Hyaloperonospora arabidopsidis.
abstract: Reliance of biotrophic pathogens on living plant tissues to propagate implies strong interdependence between host metabolism and nutrient uptake by the pathogen. However, factors determining host suitability and establishment of infection are largely unknown. We describe a loss-of-inhibition allele of ASPARTATE KINASE2 and a loss-of-function allele of DIHYDRODIPICOLINATE SYNTHASE2 identified in a screen for Arabidopsis thaliana mutants with increased resistance to the obligate biotrophic oomycete Hyaloperonospora arabidopsidis (Hpa). Through different molecular mechanisms, these mutations perturb amino acid homeostasis leading to overaccumulation of the Asp-derived amino acids Met, Thr, and Ile. Although detrimental for the plant, the mutations do not cause defense activation, and both mutants retain full susceptibility to the adapted obligate biotrophic fungus Golovinomyces orontii (Go). Chemical treatments mimicking the mutants' metabolic state identified Thr as the amino acid suppressing Hpa but not Go colonization. We conclude that perturbations in amino acid homeostasis render the mutant plants unsuitable as an infection substrate for Hpa. This may be explained by deployment of the same amino acid biosynthetic pathways by oomycetes and plants. Our data show that the plant host metabolic state can, in specific ways, influence the ability of adapted biotrophic strains to cause disease.
authors.affiliation: Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Stuttmann
authors.forename: Hans-Michael
authors.initials: HM
authors.lastname: Hubberten
authors.forename: Steffen
authors.initials: S
authors.lastname: Rietz
authors.forename: Jagreet
authors.initials: J
authors.lastname: Kaur
authors.forename: Paul
authors.initials: P
authors.lastname: Muskett
authors.forename: Raphael
authors.initials: R
authors.lastname: Guerois
authors.forename: Pawel
authors.initials: P
authors.lastname: Bednarek
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoefgen
authors.forename: Jane E
authors.initials: JE
authors.lastname: Parker
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001222:Aspartate Kinase / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics; D006706:Homeostasis; D054884:Host-Pathogen Interactions / Q000502:physiology*; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009868:Oomycetes / Q000378:metabolism* / Q000472:pathogenicity*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D011487:Protein Conformation; D016415:Sequence Alignment
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C499581:PBS2 protein, Arabidopsis; D001222:Aspartate Kinase; D006836:Hydro-Lyases; C020040:4-hydroxy-tetrahydrodipicolinate synthase