Developmental expression and biochemical analysis of the Arabidopsis atao1 gene encoding an H2O2-generating diamine oxidase.
A copper amine oxidase encoding gene, atao1, has been isolated and characterized from Arabidopsis thaliana. Sequence analysis reveals that atao1 encodes a 668 amino acid polypeptide (ATAO1) with 48% identity to copper amine oxidases from pea and lentil. The promoter region of atao1 was transcriptionally fused with the reporter genes encoding beta-glucuronidase and modified green fluorescent protein. Analysis of transgenic Arabidopsis together with in situ hybridization of wild-type plants reveals temporally and spatially discrete patterns of gene expression in lateral root cap cells, vascular tissue of roots, developing leaves, the hypocotyl, and in the style/stigmatal tissue. Enzyme activity assays show that ATAO1 preferentially oxidizes the aliphatic diamine putrescine with production of the corresponding aldehyde, ammonia and hydrogen peroxide, a recognized plant signal molecule and substrate for peroxidases. Histochemical analysis reveals that atao1 expression in developing tracheary elements precedes and overlaps with lignification and therefore is a good marker for vascular development. In both vascular tissue and the root cap, atao1 expression occurs in cells destined to undergo programmed cell death.
Møller
S G
SG
Centre for Plant Biochemistry and Biotechnology, University of Leeds, UK.
McPherson
M J
MJ
D006631:Amine Oxidase (Copper-Containing) / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D017209:Apoptosis; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D002473:Cell Wall / Q000378:metabolism; D003001:Cloning, Molecular; D003432:Cross-Linking Reagents; D017931:DNA Primers / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism*; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000201:enzymology; D030821:Plants, Genetically Modified; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D003432:Cross-Linking Reagents; D017931:DNA Primers; D006861:Hydrogen Peroxide; D006631:Amine Oxidase (Copper-Containing)