title: Overexpression of the TIR-X gene results in a dwarf phenotype and activation of defense-related gene expression in Arabidopsis thaliana.
abstract: The Arabidopsis genome encodes various proteins with a Toll/interleukin-1 receptor (TIR) domain. Many of these proteins also contain nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains and function as resistance (R) proteins. However, the protein encoded by At2g32140 (a TIR-X gene) contains a TIR domain but lacks NBS and LRR domains. We found that transgenic plants overexpressing At2g32140 displayed a dwarf phenotype and showed increased expression of defense-related genes. In general, the growth defect caused by activation of defense responses is suppressed under high-temperature conditions. However, transgenic plants overexpressing At2g32140 displayed a much stronger dwarf phenotype at 28°C than at 22°C. This dwarf phenotype was suppressed under the combination with known salicylic-acid pathway mutants. These findings suggest that At2g32140 encodes a protein involved in the plant defense response.
authors.affiliation: Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda-ku, Tokyo 120-8554, Japan.
authors.forename: Tamao
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan; Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Ito
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Tokyo 113-0033, Japan.
authors.forename: Yoshibumi
authors.initials: Y
authors.lastname: Komeda
authors.affiliation: Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan. Electronic address: atsushi@sci.hokudai.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kato
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000276:immunology / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000276:immunology / Q000502:physiology; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology*; D057865:Plant Immunity / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000276:immunology / Q000502:physiology; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction; D013696:Temperature
chemical_list: D029681:Arabidopsis Proteins; C000592953:At2g32140 protein, Aeabidopsis; D011956:Receptors, Cell Surface; D020156:Salicylic Acid
keywords: Arabidopsis thaliana; Dwarf phenotype; R-Gene; Salicylic acid; TIR domain