title: Characterization of three homoeologous cDNAs encoding chloroplast-targeted aminolevulinic acid dehydratase in common wheat.
abstract: In the tetrapyrrole biosynthetic pathway of higher plants, 5-aminolevulinic acid (ALA) is metabolized by ALA dehydratase (ALAD). Here, we isolated ALAD1 cDNA from common wheat (Triticum aestivum L.) and its diploid progenitors, and produced transgenic tobacco plants expressing the wheat ALAD1 gene. The ALAD1 genes were highly conserved among wheat relatives, and three homoeologous loci of wheat ALAD1 (TaALAD1) were equally transcribed in common wheat. A transient expression assay of a TaALAD1-GFP (green fluorescent protein) fusion protein suggested that TaALAD1 is localized in chloroplasts. Overexpression of TaALAD1 in transgenic tobacco resulted in a significant increase in ALAD activity in leaves. Moreover, the transgenic tobacco showed vigorous growth and increased survival rate on medium containing ALA at herbicidal concentrations. These results indicate that wheat ALAD1 has catalytic activity in metabolizing ALA in plastids, and that ectopic expression of TaALAD1 in transgenic plants increases their tolerance to ALA application at high concentrations.
authors: Laboratory of Plant Genetics, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
authors: Yu
authors: Y
authors: Takenouchi
authors: Haruka
authors: H
authors: Nakajima
authors: Kengo
authors: K
authors: Kanamaru
authors: Shigeo
authors: S
authors: Takumi
mesh_terms: D000622:Aminolevulinic Acid / Q000494:pharmacology; D001483:Base Sequence; D002681:China; D002736:Chloroplasts / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D003470:Culture Media / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D042541:Intracellular Space / Q000187:drug effects / Q000201:enzymology; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D000623:Porphobilinogen Synthase / Q000235:genetics* / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D012689:Sequence Homology, Nucleic Acid; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D014908:Triticum / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development
chemical_list: D003470:Culture Media; D018076:DNA, Complementary; D010940:Plant Proteins; D000622:Aminolevulinic Acid; D000623:Porphobilinogen Synthase