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Postgerminative growth and lipid catabolism in oilseeds lacking the glyoxylate cycle
Citation
Eastmond, PJ and Germain, V and Lange, PR and Bryce, JH and Smith, SM and Graham, IA, Postgerminative growth and lipid catabolism in oilseeds lacking the glyoxylate cycle, Proceedings of the National Academy of Sciences of The United States of America, 97, (10) pp. 5669-5674. ISSN 0027-8424 (2000) [Refereed Article]
Copyright Statement
Copyright 2000 The National Academy of Sciences
DOI: doi:10.1073/pnas.97.10.5669
Abstract
The glyoxylate cycle is regarded as essential for postgerminative growth and seedling establishment in oilseed plants. We
have identified two allelic Arabidopsis mutants, icl-1 and icl-2, which lack the glyoxylate cycle because of the absence of the key enzyme isocitrate lyase. These mutants demonstrate that
the glyoxylate cycle is not essential for germination. Furthermore, photosynthesis can compensate for the absence of the glyoxylate
cycle during postgerminative growth, and only when light intensity or day length is decreased does seedling establishment
become compromised. The provision of exogenous sugars can overcome this growth deficiency. The icl mutants also demonstrate that the glyoxylate cycle is important for seedling survival and recovery after prolonged dark conditions
that approximate growth in nature. Surprisingly, despite their inability to catalyze the net conversion of acetate to carbohydrate,
mutant seedlings are able to break down storage lipids. Results suggest that lipids can be used as a source of carbon for
respiration in germinating oilseeds and that products of fatty acid catabolism can pass from the peroxisome to the mitochondrion
independently of the glyoxylate cycle. However, an additional anaplerotic source of carbon is required for lipid breakdown
and seedling establishment. This source can be provided by the glyoxylate cycle or, in its absence, by exogenous sucrose or
photosynthesis.
Item Details
Item Type: | Refereed Article |
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Keywords: | postgerminative growth, lipid catabolism, glyoxylate cycle, oilseed plants |
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: | 101560 |
Year Published: | 2000 |
Web of Science® Times Cited: | 219 |
Deposited By: | Plant Science |
Deposited On: | 2015-06-25 |
Last Modified: | 2015-09-21 |
Downloads: | 0 |
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