Metabolic repression of transcription in higher plants.
Using freshly isolated maize mesophyll protoplasts and a transient expression method, I showed that the transcriptional activity of seven maize photosynthetic gene promoters is specifically and coordinately repressed by the photosynthetic end products sucrose and glucose and by the exogenous carbon source acetate. Analysis of deleted, mutated, and hybrid promoters showed that sugars and acetate inhibit the activity of distinct positive upstream regulatory elements without a common consensus. The metabolic repression of photosynthetic genes overrides other forms of regulation, e.g., light, tissue type, and developmental stage. Repression by sugars and repression by acetate are mediated by different mechanisms. The identification of conditions that avoid sugar repression overcomes a major obstacle to the study of photosynthetic gene regulation in higher plants.
Sheen
J
J
Department of Genetics, Harvard Medical School, Boston, Massachusetts.
D000085:Acetates / Q000494:pharmacology*; D019342:Acetic Acid; D001483:Base Sequence; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D005947:Glucose / Q000494:pharmacology*; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000235:genetics; D010788:Photosynthesis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011523:Protoplasts / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics; D013395:Sucrose / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
D000085:Acetates; D011993:Recombinant Fusion Proteins; D013395:Sucrose; D005947:Glucose; D019342:Acetic Acid