Arabidopsis thaliana mutants disrupted in lipid mobilization

2000 ◽  
Vol 28 (6) ◽  
pp. 762-765 ◽  
Author(s):  
P. R. Lange ◽  
I. Graham
Keyword(s):  
Arabidopsis Thaliana ◽  
Glyoxylate Cycle ◽  
Lipid Mobilization ◽  
Storage Lipid ◽  
Resistant Mutants ◽  
The Glyoxylate Cycle ◽  
Exogenous Sugar

To isolate mutants in the process of lipid mobilization during post-germinative growth we employed a screen using the pro-herbicide 2,4-dichlorophenoxybutyric acid (2,4-DB). The phenotypes of a number of 2,4-DB-resistant mutants are compared with previously characterized mutants disrupted in β-oxidation or the glyoxylate cycle. We conclude that the strength of 2,4-DB resistance and the ability of the seedlings to grow in the absence of exogenous sugar are inversely correlated. Sugar dependence of 2,4-DB-resistant seedlings is a consequence of impaired storage-lipid mobilization.

Co-ordinate regulation of genes involved in storage lipid mobilization in Arabidopsis thaliana

2001 ◽  
Vol 29 (2) ◽  
pp. 283-286 ◽  
Author(s):  
E. L. Rylott ◽  
M. A. Hooks ◽  
I. A. Graham
Keyword(s):  
Arabidopsis Thaliana ◽  
Enzyme Activities ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Molecular Genetic ◽  
Regulation Of Gene Expression ◽  
Growth Period ◽  
Malate Synthase ◽  
The Glyoxylate Cycle

Molecular genetic approaches in the model plant Arabidopsis thaliana (ColO) are shedding new light on the role and control of the pathways associated with the mobilization of lipid reserves during oilseed germination and post-germinative growth. Numerous independent studies have reported on the expression of individual genes encoding enzymes from the three major pathways: β-oxidation, the glyoxylate cycle and gluconeogenesis. However, a single comprehensive study of representative genes and enzymes from the different pathways in a single plant species has not been done. Here we present results from Arabidopsis that demonstrate the co-ordinate regulation of gene expression and enzyme activities for the acyl-CoA oxidase- and 3-ketoacyl-CoA thiolasemediated steps of β-oxidation, the isocitrate lyase and malate synthase steps of the glyoxylate cycle and the phosphoenolpyruvate carboxykinase step of gluconeogenesis. The mRNA abundance and enzyme activities increase to a peak at stage 2, 48 h after the onset of seed germination, and decline thereafter either to undetectable levels (for malate synthase and isocitrate lyase) or low basal levels (for the genes of β-oxidation and gluconeogenesis). The co-ordinate induction of all these genes at the onset of germination raises the possibility that a global regulatory mechanism operates to induce the expression of genes associated with the mobilization of storage reserves during the heterotrophic growth period.

Modelling the peroxisomal carbon leak during lipid mobilization in Arabidopsis

2010 ◽  
Vol 38 (5) ◽  
pp. 1230-1233 ◽  
Author(s):  
Mark A. Hooks ◽  
Elizabeth Allen ◽  
Jonathan A.D. Wattis
Keyword(s):  
Carbon Metabolism ◽  
Glyoxylate Cycle ◽  
Seedling Development ◽  
Wild Type ◽  
Acetyl Coa ◽  
Primary Metabolite ◽  
Lipid Mobilization ◽  
Acetate Assimilation ◽  
Development Levels ◽  
The Glyoxylate Cycle

Mutation of the ACN1 (acetate non-utilizing 1) locus of Arabidopsis results in altered acetate assimilation into gluconeogenic sugars and anapleurotic amino acids and leads to an overall depression in primary metabolite levels by approx. 50% during seedling development. Levels of acetyl-CoA were higher in acn1 compared with wild-type, which is counterintuitive to the activity of ACN1 as a peroxisomal acetyl-CoA synthetase. We hypothesize that ACN1 recycles free acetate to acetyl-CoA within peroxisomes in order that carbon remains fed into the glyoxylate cycle. When ACN1 is not present, carbon in the form of acetate can leak out of peroxisomes and is reactivated to acetyl-CoA within the cytosol. Kinetic models incorporating estimates of carbon input and pathway dynamics from a variety of literature sources have proven useful in explaining how ACN1 may prevent the carbon leak and even contribute to the control of peroxisomal carbon metabolism.

The role of the glyoxylate cycle in the symbiotic fungus Tuber borchii: expression analysis and subcellular localization

2007 ◽  
Vol 52 (3-4) ◽  
pp. 159-170 ◽  
Author(s):  
Simona Abba’ ◽  
Raffaella Balestrini ◽  
Alessandra Benedetto ◽  
Hanspeter Rottensteiner ◽  
José Ramón De Lucas ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Expression Analysis ◽  
Glyoxylate Cycle ◽  
Tuber Borchii ◽  
Symbiotic Fungus ◽  
The Glyoxylate Cycle

scholarly journals Evidence that ACN1 (acetate non-utilizing 1) prevents carbon leakage from peroxisomes during lipid mobilization in Arabidopsis seedlings

2011 ◽  
Vol 437 (3) ◽  
pp. 505-513 ◽  
Author(s):  
Elizabeth Allen ◽  
Annick Moing ◽  
Jonathan A. D. Wattis ◽  
Tony Larson ◽  
Mickaël Maucourt ◽  
...  
Keyword(s):  
Carbon Sink ◽  
Glyoxylate Cycle ◽  
Eicosenoic Acid ◽  
Primary Metabolism ◽  
Acetyl Coa ◽  
Primary Metabolite ◽  
Lipid Mobilization ◽  
Transcript Levels ◽  
Chain Acyl ◽  
Acetate Accumulation

ACN1 (acetate non-utilizing 1) is a short-chain acyl-CoA synthetase which recycles free acetate to acetyl-CoA in peroxisomes of Arabidopsis. Pulse-chase [2-13C]acetate feeding of the mutant acn1–2 revealed that acetate accumulation and assimilation were no different to that of wild-type, Col-7. However, the lack of acn1–2 led to a decrease of nearly 50% in 13C-labelling of glutamine, a major carbon sink in seedlings, and large decreases in primary metabolite levels. In contrast, acetyl-CoA levels were higher in acn1–2 compared with Col-7. The disappearance of eicosenoic acid was slightly delayed in acn1–2 indicating only a small effect on the rate of lipid breakdown. A comparison of transcript levels in acn1–2 and Col-7 showed that induced genes included a number of metabolic genes and also a large number of signalling-related genes. Genes repressed in the mutant were represented primarily by embryogenesis-related genes. Transcript levels of glyoxylate cycle genes also were lower in acn1–2 than in Col-7. We conclude that deficiency in peroxisomal acetate assimilation comprises only a small proportion of total acetate use, but this affects both primary metabolism and gene expression. We discuss the possibility that ACN1 safeguards against the loss of carbon as acetate from peroxisomes during lipid mobilization.

Regulation of the glyoxylate cycle inAcetobacter aceti

1977 ◽  
Vol 33 (1) ◽  
pp. 140-140
Author(s):  
S. Brunner ◽  
L. Ettlinger
Keyword(s):  
Glyoxylate Cycle ◽  
The Glyoxylate Cycle

Arabidopsis peroxisomal malate dehydrogenase functions in β-oxidation but not in the glyoxylate cycle

2007 ◽  
Vol 50 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Itsara Pracharoenwattana ◽  
Johanna E. Cornah ◽  
Steven M. Smith
Keyword(s):  
Malate Dehydrogenase ◽  
Glyoxylate Cycle ◽  
The Glyoxylate Cycle

scholarly journals Selenate-resistant mutants of Arabidopsis thaliana identify Sultr1;2, a sulfate transporter required for efficient transport of sulfate into roots

2002 ◽  
Vol 29 (4) ◽  
pp. 475-486 ◽  
Author(s):  
Nakako Shibagaki ◽  
Alan Rose ◽  
Jeffrey P. McDermott ◽  
Toru Fujiwara ◽  
Hiroaki Hayashi ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Sulfate Transporter ◽  
Resistant Mutants ◽  
Efficient Transport

The glyoxylate cycle is required for fungal virulence

Nature ◽  
2001 ◽  
Vol 412 (6842) ◽  
pp. 83-86 ◽  
Author(s):  
Michael C. Lorenz ◽  
Gerald R. Fink
Keyword(s):  
Glyoxylate Cycle ◽  
Fungal Virulence ◽  
The Glyoxylate Cycle
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