TY - JOUR

T1 - Combining proteomics of root and shoot mitochondria and transcript analysis to define constitutive and variable components in plant mitochondria

AU - Lee, Chun Pong

AU - Eubel, Holger

AU - O'Toole, Nicholas

AU - Millar, A. Harvey

N1 - Funding information: This work was supported by grants from the Australian Research Council (ARC) through the Centres of Excellence Program ( CE0561495 ) and by the WA State Government support to the Centre for Computational Systems Biology. C.P.L. is supported by an Australian Postgraduate Award, H.E. by an ARC Australian Post-Doctoral Fellowship and A.H.M. by an ARC Australian Professorial Fellowship.

PY - 2011/7

Y1 - 2011/7

N2 - Mitochondria undertake respiration in plant cells, but through metabolic plasticity utilize differ proportions of substrates and deliver different proportions of products to cellular metabolic and biosynthetic pathways. In Arabidopsis the mitochondrial proteome from shoots and cell culture have been reported, but there has been little information on mitochondria in roots. We compare the root mitochondrial proteome with mitochondria isolated from photosynthetic shoots to define the role of protein abundance in these differences. The major differences observed were in the abundance and/or activities of enzymes in the TCA cycle and the mitochondrial enzymes involved in photorespiration. Metabolic pathways linked to TCA cycle and photorespiration were also altered, namely cysteine, formate and one-carbon metabolism, as well as amino acid metabolism focused on 2-oxoglutarate generation. Comparisons to microarray analysis of these same tissues showed a positive correlation between mRNA and mitochondrial protein abundance, but still ample evidence for the role of post-transcriptional processes in defining mitochondrial composition. Broader comparisons of transcript abundances for mitochondrial components across Arabidopsis tissues provided additional evidence for specialization of plant mitochondria, and clustering of these data in functional groups showed the constitutive vs variably expressed components of plant mitochondria.

AB - Mitochondria undertake respiration in plant cells, but through metabolic plasticity utilize differ proportions of substrates and deliver different proportions of products to cellular metabolic and biosynthetic pathways. In Arabidopsis the mitochondrial proteome from shoots and cell culture have been reported, but there has been little information on mitochondria in roots. We compare the root mitochondrial proteome with mitochondria isolated from photosynthetic shoots to define the role of protein abundance in these differences. The major differences observed were in the abundance and/or activities of enzymes in the TCA cycle and the mitochondrial enzymes involved in photorespiration. Metabolic pathways linked to TCA cycle and photorespiration were also altered, namely cysteine, formate and one-carbon metabolism, as well as amino acid metabolism focused on 2-oxoglutarate generation. Comparisons to microarray analysis of these same tissues showed a positive correlation between mRNA and mitochondrial protein abundance, but still ample evidence for the role of post-transcriptional processes in defining mitochondrial composition. Broader comparisons of transcript abundances for mitochondrial components across Arabidopsis tissues provided additional evidence for specialization of plant mitochondria, and clustering of these data in functional groups showed the constitutive vs variably expressed components of plant mitochondria.

KW - Arabidopsis thaliana

KW - Mitochondria

KW - Photorespiration

KW - Proteomics

KW - TCA cycle

UR - http://www.scopus.com/inward/record.url?scp=79958172874&partnerID=8YFLogxK

U2 - 10.1016/j.phytochem.2010.12.004

DO - 10.1016/j.phytochem.2010.12.004

M3 - Article

AN - SCOPUS:79958172874

VL - 72

SP - 1092

EP - 1108

JO - PHYTOCHEMISTRY

JF - PHYTOCHEMISTRY

SN - 0031-9422

IS - 10

ER -