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Regulation of expression of the cucumber isocitrate lyase gene in cotyledons upon seed germination and by sucrose


Reynolds, SJ and Smith, SM, Regulation of expression of the cucumber isocitrate lyase gene in cotyledons upon seed germination and by sucrose, Plant Molecular Biology, 29, (5) pp. 885-896. ISSN 0167-4412 (1995) [Refereed Article]

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Copyright 1995 Kluwer Academic Publisher

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DOI: doi:10.1007/BF00014963


A 6.5 kb cucumber genomic DNA fragment containing the icl gene was introduced into Nicotiana plumbaginifolia and shown to direct isocitrate lyase (ICL) mRNA synthesis in transgenic seedlings upon germination, in a temporally regulated manner. Two putative icl promoter fragments, of 2900 and 572 bp, were subsequently linked to the GUS reporter gene and introduced into N. plumbaginifolia. Both constructs directed GUS expression after transgenic seed germination, and although the 572 bp fragment gave only 1 ~o of the activity of the 2900 bp fragment, it directed expression in the same cotyledon-specific and temporally regulated pattern. Seedlings were transferred to darkness after 18 days growth in the light, to induce a starvation response. The 2900 bp construct was activated by starvation and repressed by exogenous sucrose, whereas the 572 bp construct was not starvation-responsive. To localize the region of the 2900 bp promoter fragment which is responsible for regulation by sucrose, further deletions were made, linked to GUS, and assayed in a cucumber protoplast transient assay system. Constructs with promoters of 2900, 2142 and 1663 bp were activated by starvation and repressed by sucrose, but promoters of 1142 and 572 bp showed no such response. We conclude that the icl gene promoter contains at least two distinct cis-acting elements, one required for the response to sucrose and the other which participates in expression upon seed germination.

Item Details

Item Type:Refereed Article
Keywords:cucumber (Cucumis sativus L.), gene transcription, germination, glyoxylate cycle, isocitrate lyase, metabolic regulation Abstract
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
UTAS Author:Smith, SM (Professor Steven Smith)
ID Code:101585
Year Published:1995
Web of Science® Times Cited:23
Deposited By:Plant Science
Deposited On:2015-06-26
Last Modified:2015-09-21

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