title: Stress promotes Arabidopsis - Piriformospora indica interaction.
abstract: The endophytic fungus Piriformospora indica colonizes Arabidopsis thaliana roots and promotes plant performance, growth and resistance/tolerance against abiotic and biotic stress. Here we demonstrate that the benefits for the plant increase when the two partners are co-cultivated under stress (limited access to nutrient, exposure to heavy metals and salt, light and osmotic stress, pathogen infection). Moreover, physical contact between P. indica and Arabidopsis roots is necessary for optimal growth promotion, and chemical communication cannot replace the physical contact. Lower nutrient availability down-regulates and higher nutrient availability up-regulates the plant defense system including the expression of pathogenesis-related genes in roots. High light, osmotic and salt stresses support the beneficial interaction between the plant and the fungus. P. indica reduces stomata closure and H2O2 production after Alternaria brassicae infection in leaves and suppresses the defense-related accumulation of the phytohormone jasmonic acid. Thus, shifting the growth conditions toward a stress promotes the mutualistic interaction, while optimal supply with nutrients or low stress diminishes the benefits for the plant in the symbiosis.
authors.affiliation: a Institute of General Botany and Plant Physiology; Friedrich-Schiller-University Jena ; Jena , Germany.
authors.forename: Khabat
authors.initials: K
authors.lastname: Vahabi
authors.affiliation: b Institute of General Microbiology and Microbe Genetics; Friedrich-Schiller-University Jena ; Jena , Germany.
authors.forename: Sedigheh Karimi
authors.initials: SK
authors.lastname: Dorcheh
authors.affiliation: c Leibniz Institute of Age Research ; Jena , Germany.
authors.forename: Shamci
authors.initials: S
authors.lastname: Monajembashi
authors.affiliation: d Electron Microscopy Center; Friedrich-Schiller-University Jena ; Jena , Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Westermann
authors.affiliation: e Max Planck Institute for Chemical Ecology ; Jena , Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Reichelt
authors.affiliation: a Institute of General Botany and Plant Physiology; Friedrich-Schiller-University Jena ; Jena , Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Falkenberg
authors.affiliation: c Leibniz Institute of Age Research ; Jena , Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hemmerich
authors.affiliation: a Institute of General Botany and Plant Physiology; Friedrich-Schiller-University Jena ; Jena , Germany.
authors.forename: Irena
authors.initials: I
authors.lastname: Sherameti
authors.affiliation: a Institute of General Botany and Plant Physiology; Friedrich-Schiller-University Jena ; Jena , Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Oelmüller
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000382:microbiology* / Q000502:physiology* / Q000528:radiation effects; D001487:Basidiomycota / Q000187:drug effects / Q000502:physiology*; D003517:Cyclopentanes / Q000494:pharmacology; D003979:Diazonium Compounds / Q000494:pharmacology; D054884:Host-Pathogen Interactions / Q000187:drug effects / Q000528:radiation effects; D007532:Isoleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008027:Light; D019216:Metals, Heavy / Q000633:toxicity; D009566:Nitrates / Q000494:pharmacology; D009997:Osmotic Pressure / Q000187:drug effects; D054883:Oxylipins / Q000494:pharmacology; D010710:Phosphates / Q000494:pharmacology; D018517:Plant Roots / Q000382:microbiology / Q000528:radiation effects / Q000648:ultrastructure; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D011725:Pyridines / Q000494:pharmacology; D036226:Seedlings / Q000254:growth & development / Q000382:microbiology / Q000528:radiation effects; D013312:Stress, Physiological / Q000187:drug effects / Q000528:radiation effects; D013431:Sulfates / Q000494:pharmacology
chemical_list: D003517:Cyclopentanes; D003979:Diazonium Compounds; D019216:Metals, Heavy; D009566:Nitrates; D054883:Oxylipins; D010710:Phosphates; D011725:Pyridines; D013431:Sulfates; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; C056727:2-(2'-pyridyldithio)benzyldiazoacetate; C011006:jasmonic acid
keywords: Biophoton; biotic and abiotic stress; defense; light stress; metal resistance; mutualism; osmotic stress; phytohormones; reactive oxygen species; root architecture; salt stress; stomata