Expression of Atropa belladonna putrescine N-methyltransferase gene in root pericycle.
The cDNAs encoding putrescine N-methyltransferase (PMT), which catalyzes the S-adenosylmethionine-dependent N-methylation of putrescine at the first committed step in the biosynthetic pathways of tropane alkaloids, were isolated from Atropa belladonna and Hyoscyamus niger. These PMTs, however, lacked the N-terminal tandem repeat arrays previously found in Nicotiana PMTs. AbPMT1 RNA was much more abundant in the root of A. belladonna than was AbPMT2 RNA. The 5'-flanking region of the AbPMT1 gene was fused to the beta-glucuronidase (GUS) reporter gene and transferred to A. belladonna. Histochemical analysis showed that GUS is expressed specifically in root pericycle cells and that the 0.3-kb 5'-upstream region was sufficient for pericycle-specific expression. Treatment of A. belladonna roots with methyl jasmonate did not up-regulate the expression of GUS or endogenous AbPMT genes. The regulation of tropane alkaloid biosynthesis is discussed and compared with that of nicotine biosynthesis.
Suzuki
K
K
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Japan.
Yamada
Y
Y
Hashimoto
T
T
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008780:Methyltransferases / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000201:enzymology; D030821:Plants, Genetically Modified; D017386:Sequence Homology, Amino Acid; D019657:Solanaceae / Q000201:enzymology / Q000235:genetics*
D018076:DNA, Complementary; D008780:Methyltransferases; C112598:putrescine N-methyltransferase