Analysis of a Range of Catabolic Mutants Provides Evidence That Phytanoyl-Coenzyme A Does Not Act as a Substrate of the Electron-Transfer Flavoprotein/Electron-Transfer Flavoprotein:Ubiquinone Oxidoreductase Complex in Arabidopsis during Dark-Induced Senescence

被引：35

作者：

Araujo, Wagner L. ^{[1
,2
]}

Ishizaki, Kimitsune ^{[3
]}

Nunes-Nesi, Adriano ^{[1
,2
]}

Tohge, Takayuki ^{[1
]}

Larson, Tony R. ^{[4
]}

Krahnert, Ina ^{[1
]}

Balbo, Ilse ^{[1
]}

Witt, Sandra ^{[1
]}

Doermann, Peter ^{[5
]}

Graham, Ian A. ^{[4
]}

Leaver, Christopher J. ^{[6
]}

Fernie, Alisdair R. ^{[1
]}

机构：

[1] Max Planck Inst Mol Pflanzenphysiol, D-14476 Potsdam, Germany

[2] Univ Fed Vicosa, Max Planck Partner Grp, Dept Biol Vegetal, BR-36570000 Vicosa, MG, Brazil

[3] Kyoto Univ, Grad Sch Biostudies, Kyoto 6068502, Japan

[4] Univ York, Ctr Novel Agr Prod, Dept Biol, York YO10 5YW, N Yorkshire, England

[5] Univ Bonn, Inst Plant Mol Physiol & Biotechnol, Dept Mol Biotechnol, D-53115 Bonn, Germany

[6] Univ Oxford, Dept Plant Sci, Oxford OX1 3RB, England

来源：

PLANT PHYSIOLOGY | 2011年 / 157卷 / 01期

关键词：

ACYL-COA DEHYDROGENASES; ACID ALPHA-OXIDATION; BETA-OXIDATION; CHLOROPHYLL BREAKDOWN; UBIQUINONE OXIDOREDUCTASE; GAS-CHROMATOGRAPHY; REFSUMS-DISEASE; GENE-EXPRESSION; RAT-LIVER; CHAIN;

D O I：

10.1104/pp.111.182188

中图分类号：

Q94 [植物学];

学科分类号：

071001 [植物学];

摘要：

The process of dark-induced senescence in plants is not fully understood, however, the functional involvement of an electron-transfer flavoprotein/electron-transfer flavoprotein: ubiquinone oxidoreductase (ETF/ETFQO), has been demonstrated. Recent studies have revealed that the enzymes isovaleryl-coenzyme A (CoA) dehydrogenase and 2-hydroxyglutarate dehydrogenase act as important electron donors to this complex. In addition both enzymes play a role in the breakdown of cellular carbon storage reserves with isovaleryl-CoA dehydrogenase being involved in degradation of the branched-chain amino acids, phytol, and lysine while 2-hydroxyglutarate dehydrogenase is exclusively involved in lysine degradation. Given that the chlorophyll breakdown intermediate phytanoyl-CoA accumulates dramatically both in knockout mutants of the ETF/ETFQO complex and of isovaleryl-CoA dehydrogenase following growth in extended dark periods we have investigated the direct importance of chlorophyll breakdown for the supply of carbon and electrons during this process. For this purpose we isolated three independent Arabidopsis (Arabidopsis thaliana) knockout mutants of phytanoyl-CoA 2-hydroxylase and grew them under the same extended darkness regime as previously used. Despite the fact that these mutants accumulated phytanoyl-CoA and also 2-hydroxyglutarate they exhibited no morphological changes in comparison to the other mutants previously characterized. These results are consistent with a single entry point of phytol breakdown into the ETF/ETFQO system and furthermore suggest that phytol is not primarily metabolized by this pathway. Furthermore analysis of isovaleryl-CoA dehydrogenase/2-hydroxyglutarate dehydrogenase double mutants generated here suggest that these two enzymes essentially account for the entire electron input via the ETF complex.

引用

页码：55 / 69

页数：15

共 57 条

[1]

Identification of the 2-Hydroxyglutarate and Isovaleryl-CoA Dehydrogenases as Alternative Electron Donors Linking Lysine Catabolism to the Electron Transport Chain of Arabidopsis Mitochondria [J].