Work

Cardiolipin Supports Respiratory Enzymes in Plants in Different Ways

Year: 2017

Type: article

Abstract: In eukaryotes the presence of the dimeric phospholipid cardiolipin is limited to the mitochondrial membranes. It resides predominantly in the inner membrane where it interacts with components of the mitochondrial electron transfer chain. Cardiolipin deficiency has previously been shown to affect abundances of the plant NADH-dehydrogenase complex and its association with dimeric cyctochrome c reductase. Using an Arabidopsis thaliana knock-out mutant for the final enzyme of cardiolipin biosynthesis we here extend current knowledge on the dependence of plant respiration on cardiolipin. By correlating respiratory enzyme abundances with enzymatic capacities in mitochondria isolated from wild type, cardiolipin deficient and cardiolipin complemented heterotrophic cell culture lines a new picture of the participation of cardiolipin in plant respiration is emerging. Data indicate a loss of a general reduction of respiratory capacity in cardiolipin deficient mitochondria which cannot solely be attributed to decreased abundances or capacities of mitochondrial electron transfer protein complexes and supercomplexes. Instead, it most likely is the result of a loss of the mobile electron carrier cytochrome c. Furthermore, enzymes of the tricarboxylic acid cycle are found to have lower maximum activities in the mutant, including the succinate dehydrogenase complex. Interestingly, abundance of the latter is not altered, indicative of a direct impact of cardiolipin deficiency on the enzymatic capacity of this electron transfer chain protein complex.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2017.00072