Structure and expression analyses of the S-adenosylmethionine synthetase gene family in Arabidopsis thaliana.
The plant, Arabidopsis thaliana, contains two S-adenosylmethionine synthetase-encoding genes (sam). Here, we analyze the structure and expression of the sam-2 gene and compare it with the previously described sam-1 gene. Northern-blot analysis using gene-specific probes shows that both sam-1 and sam-2 are highly expressed in stem, root, and callus tissue. This similar expression pattern might be mediated by the presence of three highly conserved sequences in the 5' region of both sam genes. Using a chimeric beta-glucuronidase (GUS)-encoding gene, we show that in transgenic tobacco plants, 748 bp of 5' sam-1 sequences generate high GUS activity in the same type of tissues as previously observed in transgenic A. thaliana plants. A deletion analysis of these 5' sam-1 sequences indicates that 224 bp of 5' sam-1 sequences can still induce higher expression of the gene in stem and root relative to leaf. However, the level of expression is reduced when compared to the expression level obtained with the full-length promoter.
Peleman
J
J
Laboratorium voor Genetica, Rijksuniversiteit Gent, Belgium.
Saito
K
K
Cottyn
B
B
Engler
G
G
Seurinck
J
J
Van Montagu
M
M
Inzé
D
D
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D015723:Gene Library; D005796:Genes; D005966:Glucuronidase / Q000378:metabolism; D019868:Kanamycin Kinase; D008716:Methionine Adenosyltransferase / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010770:Phosphotransferases / Q000378:metabolism; D010944:Plants / Q000235:genetics*; D010947:Plants, Toxic; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D012313:RNA / Q000302:isolation & purification; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014026:Nicotiana / Q000235:genetics; D014158:Transcription, Genetic; D014166:Transferases / Q000235:genetics*; D014170:Transformation, Genetic
D012313:RNA; D004247:DNA; D014166:Transferases; D008716:Methionine Adenosyltransferase; D010770:Phosphotransferases; D019868:Kanamycin Kinase; D015719:Single-Strand Specific DNA and RNA Endonucleases; D005966:Glucuronidase