Organization and Regulation of Mitochondrial Respiration in Plants

Abstract

Mitochondrial respiration in plants provides energy for biosynthesis, and its balance with photosynthesis determines the rate of plant biomass accumulation. We describe recent advances in our understanding of the mitochondrial respiratory machinery of cells, including the presence of a classical oxidative phosphorylation system linked to the cytosol by transporters, discussed alongside nonphosphorylating (and, therefore, non-energy conserving) bypasses that alter the efficiency of ATP synthesis and play a role in oxidative stress responses in plants. We consider respiratory regulation in the context of the contrasting roles mitochondria play in different tissues, from photosynthetic leaves to nutrient-acquiring roots. We focus on the molecular nature of this regulation at transcriptional and post-transcriptional levels that allow the respiratory apparatus of plants to help shape organ development and the response of plants to environmental stress. We highlight the challenges for future research considering spatial and temporal changes of respiration in response to changing climatic conditions.

A poly(A)-specific ribonuclease directly regulates the poly(A) status of mitochondrial mRNA in Arabidopsis

“…The genetic resources of the AHG2-AGS1 system will be useful in addressing this missing link. PARN has been reported to be involved in vital biological functions through regulation of the poly(A) tract of cytoplasmic RNA in various organisms including plants [39][40][41] . As following this line, the recent report proposed that AHG2 negatively regulates posttranscriptional gene silencing in cytoplasm 33 .…”

In vitro inhibition of pigmentation and fiber development in colored cotton

“…Thus mitochondrial respiration will be negatively affected and adenosine triphosphate (ATP) production will be lowered as well (Jacobus et al, 1982;Li et al, 2003). A great deal of energy is required for the development of a zygote into an embryo, followed by maturation of the seed, and this energy is supplied by mitochondria through the catabolic process of respiration (Millar et al, 2011).…”

Plant respiration under low oxygen

“…Respiration involves the participation of different processes responsible for the oxidation of glucose molecules for energy and C structures, either in the presence (aerobic) (Millar et al, 2011;van Dongen et al, 2011) or absence (anaerobic) of oxygen . In the latter case, the most affected organ is the root, inducing partial oxidation strategies of substrates in order to continue to generate energy without oxygen (O 2 ).…”

“…To these is added a fourth process; transport of the products of respiration. This corresponds to the movement of substrates and cofactors to facilitate the release of products throughout the cell (Millar et al, 2011). The operation of these processes is the most efficient way to obtain energy from complete oxidation of hydrocarbon substrates, both in plants and animals (Plaxton, 1996).…”

“…This process oxidizes carbohydrates through two principal pathways: glycolysis and the tricarboxylic acid (TCA) cycle. The products from these two pathways are CO 2 and the reduced compounds NAD(P)H 2 and FADH 2 , which in turn are used for oxidative phosphorylation (OXPHOS), transferring their electrons to the terminal oxidase where O 2 acts as the final electron acceptor, producing highenergy phosphate bonds (ATP) (Millar et al, 2011;van Dongen et al, 2011). ATP represents the most efficient way to obtain energy for the synthesis of biomolecules and to maintain cellular structures, transport photoassimilates, uptake ions, assimilate N and S, regulate protein turnover and maintain electrochemical potential gradients across membranes in cells (Amthor, 2000).…”