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.
References
34
Referenced
230
10.1016/S1360-1385(99)01429-6
10.1038/180035a0
10.1016/S0021-9258(18)64230-9
- H Beevers The Biochemistry of Plants, ed P K Stumpf (Academic, New York) 4, 117–130 (1980). / The Biochemistry of Plants by Beevers H (1980)
10.1038/179988a0
10.1007/BF00397663
10.2307/3869878
10.1002/j.1460-2075.1995.tb07354.x
10.1093/emboj/18.21.5843
- T ap Rees The Biochemistry of Plants, ed D D Davies (Academic, New York) 2, 1–29 (1980). / The Biochemistry of Plants by ap Rees T (1980)
- H Hayashi, K Toriyama, M Kondo, M Nishimura Plant Cell 12, 183–195 (1998). / Plant Cell by Hayashi H (1998)
10.1111/j.1399-3054.1962.tb08052.x
10.1023/A:1006082009151
10.1073/pnas.95.21.12432
10.1126/science.236.4806.1299
10.1046/j.1365-313X.1999.00559.x
10.1016/S0006-291X(79)80034-0
10.1016/S0021-9258(18)83401-9
10.1007/BF00193217
10.1016/0003-2697(76)90527-3
10.1016/0003-2697(86)90132-6
10.1002/j.1460-2075.1985.tb03671.x
10.1046/j.1365-313X.1999.00533.x
10.1104/pp.81.3.762
10.1104/pp.86.2.527
10.1105/tpc.1.3.293
10.1007/BF00224392
10.1007/978-1-4615-1747-4
10.1104/pp.101.4.1157
10.1016/S0021-9258(18)37752-4
- P Ramond, A Spiteri, M Dieuaide, B Gerhardt, A Pradet Plant Physiol Biochem 30, 153–161 (1992). / Plant Physiol Biochem by Ramond P (1992)
10.1104/pp.66.4.555
10.1007/s004250050496
10.1104/pp.104.3.857
Dates
Type | When |
---|---|
Created | 23 years, 1 month ago (July 26, 2002, 10:38 a.m.) |
Deposited | 3 years, 4 months ago (April 13, 2022, 5:17 p.m.) |
Indexed | 4 weeks, 2 days ago (Aug. 6, 2025, 9:32 a.m.) |
Issued | 25 years, 3 months ago (May 9, 2000) |
Published | 25 years, 3 months ago (May 9, 2000) |
Published Online | 25 years, 3 months ago (May 9, 2000) |
Published Print | 25 years, 3 months ago (May 9, 2000) |
@article{Eastmond_2000, title={Postgerminative growth and lipid catabolism in oilseeds lacking the glyoxylate cycle}, volume={97}, ISSN={1091-6490}, url={http://dx.doi.org/10.1073/pnas.97.10.5669}, DOI={10.1073/pnas.97.10.5669}, number={10}, journal={Proceedings of the National Academy of Sciences}, publisher={Proceedings of the National Academy of Sciences}, author={Eastmond, Peter J. and Germain, Veronique and Lange, Peter R. and Bryce, James H. and Smith, Steven M. and Graham, Ian A.}, year={2000}, month=may, pages={5669–5674} }