Sugar-inducible expression of a gene for beta-amylase in Arabidopsis thaliana.
The levels of beta-amylase activity and of the mRNA for beta-amylase in rosette leaves of Arabidopsis thaliana (L.) Heynh. increased significantly, with the concomitant accumulation of starch, when whole plants or excised mature leaves were supplied with sucrose. A supply of glucose or fructose, but not of mannitol or sorbitol, to plants also induced the expression of the gene for beta-amylase, and the induction occurred not only in rosette leaves but also in roots, stems, and bracts. These results suggest that the gene for beta-amylase of Arabidopsis is subject to regulation by a carbohydrate metabolic signal, and expression of the gene in various tissues may be regulated by the carbon partitioning and sink-source interactions in the whole plant. The sugar-inducible expression of the gene in Arabidopsis was severely repressed in the absence of light. The sugar-inducible expression in the light was not inhibited by 3(3,4-dichlorophenyl)-1,1-dimethylurea or by chloramphenicol, but it was inhibited by cycloheximide. These results suggest that a light-induced signal and de novo synthesis of proteins in the cytoplasm are involved in the regulation. A fusion gene composed of the 5' upstream region of the gene for beta-amylase from Arabidopsis and the coding sequence of beta-glucuronidase showed the sugar-inducible expression in a light-dependent manner in rosette leaves of transgenic Arabidopsis.
Mita
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S
Laboratory of Biochemistry, School of Agricultural Sciences, Nagoya University, Japan.
Suzuki-Fujii
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K
Nakamura
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K
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D002241:Carbohydrates / Q000494:pharmacology*; D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics; D001614:beta-Amylase / Q000235:genetics*
D002241:Carbohydrates; D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D009687:Nuclear Proteins; D001614:beta-Amylase