title: The role of Arabidopsis thaliana NAR1, a cytosolic iron-sulfur cluster assembly component, in gametophytic gene expression and oxidative stress responses in vegetative tissue.
abstract: Iron-sulfur proteins have iron-sulfur clusters as a prosthetic group and are responsible for various cellular processes, including general transcriptional regulation, photosynthesis and respiration. The cytosolic iron-sulfur assembly (CIA) pathway of yeast has been shown to be responsible for regulation of iron-sulfur cluster assembly in both the cytosol and the nucleus. However, little is known about the roles of this pathway in multicellular organisms. In a forward genetic screen, we identified an Arabidopsis thaliana mutant with impaired expression of the endosperm-specific gene Flowering Wageningen (FWA). To characterize this mutant, we carried out detailed phenotypic and genetic analyses during reproductive and vegetative development. The mutation affects NAR1, which encodes a homolog of a yeast CIA pathway component. Comparison of embryo development in nar1-3 and other A. thaliana mutants affected in the CIA pathway showed that the embryos aborted at a similar stage, suggesting that this pathway potentially functions in early seed development. Transcriptome analysis of homozygous viable nar1-4 seedlings showed transcriptional repression of a subset of genes involved in 'iron ion transport' and 'response to nitrate'. nar1-4 also exhibited resistance to the herbicide paraquat. Our results indicate that A. thaliana NAR1 has various functions including transcriptional regulation in gametophytes and abiotic stress responses in vegetative tissues.
authors.affiliation: Plant Reproductive Genetics Group, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Plant Reproductive Genetics Group, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan.
authors.forename: Diana Mihaela
authors.initials: DM
authors.lastname: Buzas
authors.affiliation: Department of Biology, Faculty of Science, Niigata University, Ikarashi, Niigata, 950-2181, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kato
authors.affiliation: Plant Genetics Laboratory, National Institute of Genetics, Mishima, 411-8540, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Plant Genetics Laboratory, National Institute of Genetics, Mishima, 411-8540, Japan.
authors.forename: Nori
authors.initials: N
authors.lastname: Kurata
authors.affiliation: Plant Reproductive Genetics Group, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D000154:Aconitate Hydratase / Q000378:metabolism; D000483:Alleles; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003433:Crosses, Genetic; D003600:Cytosol / Q000378:metabolism*; D056625:Endosperm / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D018392:Genomic Imprinting; D055993:Germ Cells, Plant / Q000166:cytology / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006579:Heterozygote; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics*; D010269:Paraquat / Q000633:toxicity; D010641:Phenotype; D054817:Pollination; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000196:embryology / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007506:Iron-Sulfur Proteins; C586707:NAR1 protein, Arabidopsis; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D000154:Aconitate Hydratase; D010269:Paraquat
keywords: Arabidopsis thaliana; cytosolic iron-sulfur (Fe-S) cluster assembly; endosperm; imprinted gene; paraquat resistance