Li(+)-regulated 1-aminocyclopropane-1-carboxylate synthase gene expression in Arabidopsis thaliana.
In Arabidopsis thaliana, 1-aminocyclopropane-1-carboxylate synthase (ACS) is encoded by a multigene family consisting of at least five members whose expression is induced by hormones, developmental signals, and protein synthesis inhibition. Li+, known to interfere with the phosphoinositide (PI) second messenger system by inhibiting the activity of inositol-phosphate phosphatases, is one of the strongest inducers of ACC synthase activity in plants. Treatment of etiolated Arabidopsis seedlings with LiCl results in a rapid induction of the ACS5 gene. Also, LiCl represses the cycloheximide (CHX)-induced accumulation of the ACS2 mRNA. The effects of Li+ on the expression of ACS5 and ACS2 are specific, dose-dependent, and can be reversed by Ca2+ and mimicked by the protein kinase inhibitor K-252a. The results suggest that the regulation of some ACS genes by various inducers may involve protein kinase activity, which in turn may be controlled through an inositol 1,4,5-triphosphate (IP3)-mediated Ca2+ mobilization. Since plants contain no Li+, the cation appears to unmask pre-existing biochemical capacity that may be utilized by various unknown transducers during plant growth and development.
Liang
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Plant Gene Expression Center, Albany, CA 94710, USA.
Shen
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Theologis
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D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D005075:Biological Evolution; D002118:Calcium / Q000494:pharmacology; D002227:Carbazoles / Q000494:pharmacology; D003001:Cloning, Molecular; D003513:Cycloheximide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction; D004791:Enzyme Inhibitors; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D026121:Indole Alkaloids; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D008094:Lithium / Q000494:pharmacology*; D008190:Lyases / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D047428:Protein Kinase Inhibitors; D011500:Protein Synthesis Inhibitors; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D015398:Signal Transduction
D002227:Carbazoles; D004791:Enzyme Inhibitors; D026121:Indole Alkaloids; D007527:Isoenzymes; D047428:Protein Kinase Inhibitors; D011500:Protein Synthesis Inhibitors; D011993:Recombinant Fusion Proteins; C049985:staurosporine aglycone; D003513:Cycloheximide; D008094:Lithium; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase; D002118:Calcium