A putative peroxisomal polyamine oxidase, AtPAO4, is involved in polyamine catabolism in Arabidopsis thaliana.
We characterized three Arabidopsis polyamine oxidase genes, AtPAO2, AtPAO3 and AtPAO4. Transient expression of these genes as monomeric red fluorescent protein fusion proteins in Arabidopsis root cells revealed that all are peroxisomal proteins. Quantitative analysis of their transcripts in various organs suggested that AtPAO4 is the major isoform in root peroxisomes. Analysis of recombinant AtPAO4 protein indicated that it is a flavoprotein that catalyzed the oxidative conversion of spermine to spermidine. AtPAO4-deficient mutants established by using T-DNA insertion and RNA interference techniques had markedly increased spermine and decreased spermidine levels in the roots. These results suggest that AtPAO4 is a root peroxisomal polyamine oxidase that participates in polyamine catabolism. Microarray analysis showed that AtPAO4 deficiency induced alterations in the expression of genes related to the drought stress response and flavonoid biosynthesis.
Kamada-Nobusada
Tomoe
T
Division of Cell Mechanisms, Department of Cell Biology, National Institute for Basic Biology, Okazaki, 444-8585 Japan.
Hayashi
Makoto
M
Fukazawa
Mitsue
M
Sakakibara
Hitoshi
H
Nishimura
Mikio
M
D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016254:Mutagenesis, Insertional; D020411:Oligonucleotide Array Sequence Analysis; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics / Q000378:metabolism*; D020675:Peroxisomes / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D013095:Spermidine / Q000378:metabolism; D013096:Spermine / Q000378:metabolism; D013379:Substrate Specificity; D000097667:Polyamine Oxidase
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D000587:Oxidoreductases Acting on CH-NH Group Donors; D018749:RNA, Plant; D011994:Recombinant Proteins; D013095:Spermidine; D013096:Spermine; D000097667:Polyamine Oxidase; C036483:T-DNA