GrainGenes Reference Report: PPS-123-939
Reference
PPS-123-939
Title
Glucose and disaccharide-sensing mechanisms modulate the expression of alpha-amylase in barley embryos
Journal
Plant Physiology
Year
2000
Volume
123
Pages
939-948
Author
Loreti E Alpi A Perata P
Abstract
Summary: The aim of this study was to investigate the sugar-sensing processes modulating the expression of alpha-amylase in barley (Hordeum vulgaris L. var Himalaya) embryos. The results highlight the existence of independent glucose (Glc) and disaccharides sensing. Glc treatment destabilizes the alpha-amylase mRNA. Non-metabolizable disaccharides repress alpha-amylase induction, but have no effects on transcript stability. Structure-function analysis indicates that a fructose (Fru) moiety is needed for disaccharide sensing. Lactulose (beta-galactose [Gal][1 leads to 4]Fru), palatinose (Glc[1 leads to 6]Fru), and turanose (Glc[1 leads to 3]Fru) are not metabolized but repress alpha-amylase. Disrupting the fructosyl moiety of lactulose and palatinose, or replacing the Fru moiety of beta-Gal[1 leads to 4]Fru with Glc or Gal results in molecules unable to repress alpha-amylase. Comparison of the molecular requirements for sucrose transport with those for disaccharide sensing suggests that these sugars are perceived possibly at the plasma membrane level independently from sucrose transport
External Databases
Pubmed: 10889242
Keyword
GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture.
GrainGenes Reference Report: PPS-123-939
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GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture. | |||