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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
31
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pubmed:dateCreated |
1991-12-13
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pubmed:abstractText |
We present evidence to show that the alpha-amylase gene family in rice is under two different modes of regulation: 1) hormonal regulation in germinating seeds, and 2) metabolic repression in cultured cells by available carbohydrate nutrients. Expression of alpha-amylase genes in deembryoed rice seeds is known to be induced by exogenous gibberellic acid. On the other hand, expression of alpha-amylase genes in suspension-cultured cells is induced by the deprivation of carbohydrate nutrient. A lag period of 2-4 h is required for the induction of alpha-amylase mRNA in sucrose-depleted medium. The induction of alpha-amylase expression is extraordinarily high and levels of alpha-amylase mRNA can be increased 8-20-folds after 24 h of sucrose starvation. The synthesis and secretion of alpha-amylase is also dependent upon the level of carbon source. The derepression or repression of alpha-amylase synthesis can be readily reversed by the deprivation or replenishment of sucrose in the medium, respectively. Glucose and fructose exert a repression on the alpha-amylase synthesis similar to that of sucrose. A hypothesis that explains the induction of alpha-amylase synthesis by carbohydrate starvation is proposed. Our data have suggested a hitherto undiscovered, potentially important control mechanism of carbohydrate metabolism in higher plants.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Gibberellins,
http://linkedlifedata.com/resource/pubmed/chemical/Plant Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger,
http://linkedlifedata.com/resource/pubmed/chemical/alpha-Amylases,
http://linkedlifedata.com/resource/pubmed/chemical/gibberellic acid
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
5
|
pubmed:volume |
266
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
21131-7
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pubmed:dateRevised |
2008-11-21
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pubmed:meshHeading |
pubmed-meshheading:1939156-Blotting, Northern,
pubmed-meshheading:1939156-Carbohydrate Metabolism,
pubmed-meshheading:1939156-Cells, Cultured,
pubmed-meshheading:1939156-Gene Expression Regulation,
pubmed-meshheading:1939156-Gibberellins,
pubmed-meshheading:1939156-Oryza sativa,
pubmed-meshheading:1939156-Plant Proteins,
pubmed-meshheading:1939156-RNA, Messenger,
pubmed-meshheading:1939156-alpha-Amylases
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pubmed:year |
1991
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pubmed:articleTitle |
Metabolic derepression of alpha-amylase gene expression in suspension-cultured cells of rice.
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pubmed:affiliation |
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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