Mitochondrial energy-dissipation systems in plants (Review)

Plants are sessile organisms that have the ability to integrate external cues into metabolic and developmental signals. The cues initiate specific signal cascades that can enhance the tolerance of plants to stress, and these mechanisms are crucial to the survival and fitness of plants. The adaption of plants to stresses is a complex process that involves decoding stress inputs as energy-deficiency signals. The process functions through vast metabolic and/or transcriptional reprogramming to re-establish the cellular energy balance. Members of the mitochondrial energy dissipation pathway (MEDP), alternative oxidases (AOXs) and uncoupling proteins (UCPs), act as energy mediators and might play crucial roles in the adaption of plants to stresses. However, their roles in plant growth and development have been relatively less explored.

Signal cross-talk between the MEDP, ROS, calcium signalling and hormone signalling.
Signal cross-talk between the MEDP, ROS, calcium signalling and hormone signalling. Full details in Pu et al..

Pu et al. review current knowledge concerning the role of MEDP members in plant development as well as recent advances in identifying the molecular components that regulate the expression of AOXs and UCPs. The regulation of these MEDP components is complex and occurs at transcriptional, translational, post-translational and metabolic levels. The authors conclude that as a result of its cellular energy mediator functions, the MEDP integrates information from redox and energy signalling pathways with hormonal pathways that regulate plant development and stress tolerance.

This article appears in the special issue ROS and NO Reactions in Plants.