title: Monodehydroascorbate reductase 2 and dehydroascorbate reductase 5 are crucial for a mutualistic interaction between Piriformospora indica and Arabidopsis.
abstract: Ascorbate is a major antioxidant and radical scavenger in plants. Monodehydroascorbate reductase (MDAR) and dehydroascorbate reductase (DHAR) are two enzymes of the ascorbate-glutathione cycle that maintain ascorbate in its reduced state. MDAR2 (At3g09940) and DHAR5 (At1g19570) expression was upregulated in the roots and shoots of Arabidopsis seedlings co-cultivated with the root-colonizing endophytic fungus Piriformospora indica, or that were exposed to a cell wall extract or a culture filtrate from the fungus. Growth and seed production were not promoted by Piriformospora indica in mdar2 (SALK_0776335C) and dhar5 (SALK_029966C) T-DNA insertion lines, while colonized wild-type plants were larger and produced more seeds compared to the uncolonized controls. After 3 weeks of drought stress, growth and seed production were reduced in Piriformospora indica-colonized plants compared to the uncolonized control, and the roots of the drought-stressed insertion lines were colonized more heavily by the fungus than were wild-type plants. Upregulation of the message for the antimicrobial PDF1.2 protein in drought-stressed insertion lines indicated that MDAR2 and DHAR5 are crucial for producing sufficient ascorbate to maintain the interaction between Piriformospora indica and Arabidopsis in a mutualistic state.
authors.affiliation: Friedrich-Schiller-Universität Jena, Institut für Allgemeine Botanik und Pflanzenphysiologie, Dornburger Str. 159, 07743 Jena, Germany.
authors.forename: Jyothilakshmi
authors.initials: J
authors.lastname: Vadassery
authors.affiliation: Amity Institute of Herbal and Microbial Studies, Sector 125, Noida 201303, UP, India.
authors.forename: Swati
authors.initials: S
authors.lastname: Tripathi
authors.affiliation: Amity Institute of Herbal and Microbial Studies, Sector 125, Noida 201303, UP, India.
authors.forename: Ram
authors.initials: R
authors.lastname: Prasad
authors.affiliation: Amity Institute of Herbal and Microbial Studies, Sector 125, Noida 201303, UP, India.
authors.forename: Ajit
authors.initials: A
authors.lastname: Varma
authors.affiliation: Friedrich-Schiller-Universität Jena, Institut für Allgemeine Botanik und Pflanzenphysiologie, Dornburger Str. 159, 07743 Jena, Germany. Electronic address: b7oera@uni-jena.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Oelmüller
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001487:Basidiomycota / Q000502:physiology*; D015169:Colony Count, Microbial; D023082:Defensins / Q000235:genetics / Q000378:metabolism; D003683:Dehydroascorbic Acid / Q000378:metabolism; D055864:Droughts; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D018520:Plant Shoots / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000378:metabolism / Q000382:microbiology; D012639:Seeds / Q000201:enzymology / Q000254:growth & development / Q000382:microbiology; D013312:Stress, Physiological; D013559:Symbiosis; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D023082:Defensins; D003683:Dehydroascorbic Acid; D005656:Fungal Proteins; D009247:NADH, NADPH Oxidoreductases; D010088:Oxidoreductases; D012333:RNA, Messenger; C487542:At5g44420 protein, Arabidopsis; C544456:MDAR2 protein, Arabidopsis; C020666:glutathione dehydrogenase (ascorbate)