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Expression of glyoxylate cycle genes in cucumber roots responds to sugar supply and can be activated by shading or defoliation of the shoot

Citation

Ismail, I and de Bellis, L and Alpi, A and Smith, SM, Expression of glyoxylate cycle genes in cucumber roots responds to sugar supply and can be activated by shading or defoliation of the shoot, Plant Molecular Biology, 35, (5) pp. 633-640. ISSN 0167-4412 (1997) [Refereed Article]

Copyright Statement

Copyright 1997 Kluwer Academic Publishers

DOI: doi:10.1023/A:1005840522049

Abstract

When cucumber roots are excised and incubated without a carbon source, isocitrate lyase (ICL) and malate synthase (MS) mRNAs increase significantly in amount. However, if sucrose is added to the excised roots, the mRNAs do not accumulate. Hairy roots obtained by transformation with Agrobacterium rhizogenes show the same response. Transgenic hairy roots containing the Icl and Ms gene promoters fused to the GUS reporter gene, have very low GUS activity which increases dramatically when roots are incubated in the absence of sugar, indicating regulation at the transcriptional level. Staining of sugar-deprived roots shows that GUS activity is concentrated mainly in root tips and lateral root primordia, where demand for carbohydrate is greatest. In order to determine if Icl and Ms genes are expressed in roots of whole plants under conditions which may occur in nature, cucumber plants were subjected to reduced light intensity or defoliation. In both cases increases were observed in ICL and MS mRNAs. These treatments also reduced root sugar content, consistent with the hypothesis that sugar supply could control expression of Icl and Ms genes in roots of whole plants.

Item Details

Item Type:Refereed Article
Keywords:Agrobacterium rhizogenes, carbohydrate regulation, cucumber (Cucumis sativus L.), gene expression, glyoxylate cycle, hairy roots
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Plant Physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Biological Sciences
Author:Smith, SM (Professor Steven Smith)
ID Code:101579
Year Published:1997
Web of Science® Times Cited:24
Deposited By:Plant Science
Deposited On:2015-06-26
Last Modified:2015-09-21
Downloads:0

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