The role of mitochondria in plant development and stress tolerance

Authors: Liberatore, Katie; DUKOWIC-SCHULZE, STEPHANIE - University Of Minnesota; MILLER, MARISA - University Of Minnesota; CHEN, CHANGBIN - University Of Minnesota; Kianian, Shahryar

Submitted to: Free Radical Biology and Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2016
Publication Date: 3/28/2016
Citation: Liberatore, K.L., Dukowic-Schulze, S., Miller, M., Chen, C., Kianian, S. 2016. The role of mitochondria in plant development and stress tolerance. Free Radical Biology and Medicine. doi:10.1016/j.freeradbiomed.2016.03.033.

Interpretive Summary: Eukaryotic cells require orchestrated communication between nuclear and organellar genomes, perturbations in which are linked to stress response and disease in both animals and plants. In addition to mitochondria, which are found across eukaryotes, plant cells contain a second organelle, the plastid. Signaling both among the organelles (cytoplasmic) and between the cytoplasm and the nucleus (i.e. nuclear-cytoplasmic interactions (NCI) is essential for proper cellular function. A deeper understanding of NCI and its impact on development, stress response, and long-term health is needed in both animal and plant systems. Here we focus on the role of plant mitochondria in development and stress response. We compare and contrast features of plant and animal mitochondrial genomes (mtDNA), particularly highlighting the large and highly dynamic nature of plant mtDNA. Plant-based tools are powerful yet underutilized resources for enhancing our fundamental understanding of NCI. These tools also have great potential for improving crop production. Across taxa, mitochondria are most abundant in cells that have high energy or nutrient demands including at key developmental time points. Although plant mitochondria act as integrators of signals involved in both development and stress response pathways, little is known about plant mtDNA diversity and its impact on these processes. In humans, there are strong correlations between particular mitotypes (and mtDNA mutations) and developmental differences (or disease). We propose that future work in plants should focus on defining mitotypes more carefully and investigating their functional implications as well as improving techniques to facilitate this research.

Technical Abstract: Proper cellular function requires orchestrated communication among cellular compartments and the ability of the cell to sense and respond to its environment. Plant cells contain three distinct compartments that house DNA. The nucleus contains the nuclear genome, which provides a majority of a cell's genetic material. However, plant cells contain two organelles that retain their own genomes, the mitochondria and the chloroplast. These organelles are essential for energy production, nutrient sensing, metabolism, and stress response. Coordinated signaling among organelles and between the organelles and the nucleus (in both directions) impacts global gene expression and drives cellular functions. Therefore, organelles, especially mitochondria, are often referred to as "signaling hubs" within the cell. However, little is known about the genetic diversity of DNA contained in the mitochondria and chloroplasts or the mechanisms of interaction between the different cellular compartments. We highlight the unique features of plant mitochondria and the dynamics of these specialized organelles and their genomes throughout the cell cycle, development, and under stressful conditions. We discuss powerful tools available in plants to study the diversity of mitochondria DNA and how the mitochondria communicate with other cellular compartments. Understanding the communication between the main nuclear genome and organelle DNA is important to further improve productivity in crop plants including major staples such as wheat, maize, and rice.