title: Characterization of mutants in Arabidopsis showing increased sugar-specific gene expression, growth, and developmental responses.
abstract: Sugars such as sucrose serve dual functions as transported carbohydrates in vascular plants and as signal molecules that regulate gene expression and plant development. Sugar-mediated signals indicate carbohydrate availability and regulate metabolism by co-coordinating sugar production and mobilization with sugar usage and storage. Analysis of mutants with altered responses to sucrose and glucose has shown that signaling pathways mediated by sugars and abscisic acid interact to regulate seedling development and gene expression. Using a novel screen for sugar-response mutants based on the activity of a luciferase reporter gene under the control of the sugar-inducible promoter of the ApL3 gene, we have isolated high sugar-response (hsr) mutants that exhibit elevated luciferase activity and ApL3 expression in response to low sugar concentrations. Our characterization of these hsr mutants suggests that they affect the regulation of sugar-induced and sugar-repressed processes controlling gene expression, growth, and development in Arabidopsis. In contrast to some other sugar-response mutants, they do not exhibit altered responses to ethylene or abscisic acid, suggesting that the hsr mutants may have a specifically increased sensitivity to sugars. Further characterization of the hsr mutants will lead to greater understanding of regulatory pathways involved in metabolite signaling.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom.
authors.forename: Margarete
authors.initials: M
authors.lastname: Baier
authors.forename: Georg
authors.initials: G
authors.lastname: Hemmann
authors.forename: Rachel
authors.initials: R
authors.lastname: Holman
authors.forename: Fiona
authors.initials: F
authors.lastname: Corke
authors.forename: Rod
authors.initials: R
authors.lastname: Card
authors.forename: Caroline
authors.initials: C
authors.lastname: Smith
authors.forename: Fred
authors.initials: F
authors.lastname: Rook
authors.forename: Michael W
authors.initials: MW
authors.lastname: Bevan
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000494:pharmacology; D018744:DNA, Plant / Q000235:genetics; D003624:Darkness; D015870:Gene Expression; D017343:Genes, Plant; D017930:Genes, Reporter; D008156:Luciferases / Q000235:genetics; D009154:Mutation; D030821:Plants, Genetically Modified
chemical_list: D002241:Carbohydrates; D018744:DNA, Plant; D000040:Abscisic Acid; D008156:Luciferases