Stress signalling dynamics of the mitochondrial electron transport chain and oxidative phosphorylation system in higher plants

Abstract

Background Mitochondria play a diversity of physiological and metabolic roles under conditions of abiotic or biotic stress. They may be directly subjected to physico-chemical constraints, and they are also involved in integrative responses to environmental stresses through their central position in cell nutrition, respiration, energy balance and biosyntheses. In plant cells, mitochondria present various biochemical peculiarities, such as cyanide-insensitive alternative respiration, and, besides integration with ubiquitous eukaryotic compartments, their functioning must be coupled with plastid functioning. Moreover, given the sessile lifestyle of plants, their relative lack of protective barriers and present threats of climate change, the plant cell is an attractive model to understand the mechanisms of stress/organelle/cell integration in the context of environmental stress responses. Scope The involvement of mitochondria in this integration entails a complex network of signalling, which has not been fully elucidated, because of the great diversity of mitochondrial constituents (metabolites, reactive molecular species and structural and regulatory biomolecules) that are linked to stress signalling pathways. The present review analyses the complexity of stress signalling connexions that are related to the mitochondrial electron transport chain and oxidative phosphorylation system, and how they can be involved in stress perception and transduction, signal amplification or cell stress response modulation. Conclusions Plant mitochondria are endowed with a diversity of multi-directional hubs of stress signalling that lead to regulatory loops and regulatory rheostats, whose functioning can amplify and diversify some signals or, conversely, dampen and reduce other signals. Involvement in a wide range of abiotic and biotic responses also implies that mitochondrial stress signalling could result in synergistic or conflicting outcomes during acclimation to multiple and complex stresses, such as those arising from climate change.

Reduced Glutathione Protects Subcellular Compartments From Pb-Induced ROS Injury in Leaves and Roots of Upland Cotton (Gossypium hirsutum L.)

“…In this study, mitochondria were seen deformed both in terminal and median leaves, and primary and secondary roots of upland cotton under Pb exposure. These changes may be attributed to excess ROS generation, as mitochondria release free electrons in electron transport chain to form O •− and other ROSs (Dourmap et al, 2019). As a first line defense, SODs neutralize O •− in mitochondria, that's why SOD activity was increased in GSH + Pb group.…”

Employing CRISPR/Cas Technology for the Improvement of Potato and Other Tuber Crops

“…The extreme levels of abiotic stresses such as drought, flooding, salinity, mineral deficiency, low or high temperatures, high light, post-harvest problems, and accumulation of reducing sugars during cold storage have negative impact in crop yield ( Le Gall et al, 2015 ). Abiotic stresses usually lead to superoxide overproduction in mitochondria ( Dourmap et al, 2019 ). The mitochondrial respiratory chain in higher plants consists of the ATP-coupling cytochrome pathway (CP) and the cyanide (CN)-resistant respiratory pathway.…”

Roles of Organellar RNA-Binding Proteins in Plant Growth, Development, and Abiotic Stress Responses

“…A recent study has also demonstrated that chloroplast-localized SDP, which affects rRNA processing in chloroplasts under normal conditions, has positive effects on salt, heat, freezing, or UV stress tolerance, as it influences the stress-responsive genes in the nucleus [ 117 ]. Beyond organelles, it will be of great interest to investigate how nCMRBP-mediated organellar retrograde signaling (ORS) influences the reprogramming of the expression of stress-responsive nuclear genes, and the organellar and nuclear epigenetic modifications for stress priming and memory [ 101 , 118 , 119 , 120 , 121 ]. Although the study of organellar proteomics and metabolomics is far behind than those in the nucleus and cytoplasm, recent studies emphasize the importance of homeostasis between the nucleus and organelles in plant acclimation to environmental changes [ 122 , 123 , 124 , 125 ].…”