title: Mutations in Plastidial 5-Aminolevulinic Acid Biosynthesis Genes Suppress a Pleiotropic Defect in Shoot Development of a Mitochondrial GABA Shunt Mutant in Arabidopsis.
abstract: Plant developmental processes are co-ordinated with the status of cell metabolism, not only in mitochondria but also in plastids. In Arabidopsis thaliana, succinic semialdehyde (SSA), a GABA shunt metabolite, links the specific mitochondrial metabolic pathway to shoot development. To understand the mechanism of SSA-mediated development, we isolated a succinic semialdehyde dehydrogenase (ssadh) suppressor mutant, affected in its ability to catalyze SSA to succinic acid. We found that pleiotropic developmental phenotypes of ssadh are suppressed by a mutation in GLUTAMATE-1-SEMIALDEHYDE 2, 1-AMINOMUTASE 2 (GSA2), which encodes a plastidial enzyme converting glutatamate-1-semialdehyde to 5-aminolevulinic acid (5-ALA). In addition, a mutation in either HEMA1 or GSA1, two other enzymes for 5-ALA synthesis, also suppressed ssadh fully and partially, respectively. Furthermore, exogenous application of 5-ALA and SSA disturbed leaf development. These results suggest that metabolism in both mitochondria and plastids affect shoot development.
authors.affiliation: National Institute for Basic Biology, Okazaki, Aichi, 444-8585 Japan Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan toyokura@port.kobe-u.ac.jp kiyo@nins.jp kiyo@agr.ryukoku.ac.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Toyokura
authors.affiliation: National Institute for Basic Biology, Okazaki, Aichi, 444-8585 Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Yamaguchi
authors.affiliation: National Institute for Basic Biology, Okazaki, Aichi, 444-8585 Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Shigenobu
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Fukaki
authors.affiliation: National Institute for Basic Biology, Okazaki, Aichi, 444-8585 Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Tatematsu
authors.affiliation: National Institute for Basic Biology, Okazaki, Aichi, 444-8585 Japan Department of Agriculture, Ryukoku University, Yokatani 1-5, Seta Ohe-cho, Otsu-shi, Shiga 520-2194, Japan toyokura@port.kobe-u.ac.jp kiyo@nins.jp kiyo@agr.ryukoku.ac.jp.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Okada
mesh_terms: D000595:Amino Acid Sequence; D000622:Aminolevulinic Acid / Q000378:metabolism* / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D061125:Genes, Chloroplast; D016153:Genes, Suppressor; D058685:Genetic Pleiotropy / Q000187:drug effects; D018519:Meristem / Q000235:genetics; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D018087:Plastids / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D013489:Suppression, Genetic; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D005680:gamma-Aminobutyric Acid; D000622:Aminolevulinic Acid
keywords: GABA shunt; GSA; Leaf development; SSADH; Tetrapyrrole biosynthetic pathway