Does the alternative respiratory pathway offer protection against the adverse effects resulting from climate change?

Abstract

Elevated greenhouse gases (GHG) induce adverse conditions directly and indirectly causing decreases in plant productivity. To deal with climate change effects, plants have developed various mechanisms including the fine-tuning of metabolism. Plant respiratory metabolism is highly flexible due to presence of various alternative pathways. The mitochondrial alternative oxidase (AOX) respiratory pathway is responsive to these changes and several lines of evidence suggest it plays a role in reducing excesses of ROS and RNS while providing metabolic flexibility under stress. Here we discuss the importance of the AOX pathway in dealing with elevated carbon dioxide (CO2), nitrogen oxides (NOx), ozone (O3) and the main abiotic stresses induced by climate change. Recent advances in our understanding concerning the in vivo regulation of AOX and its structural properties suggest that novel AOXs with altered regulatory properties could be used in future gene editing strategies. We suggest that fine-tune modulation of the regulatory properties of AOX and targeting its expression in different plant tissues could improve plant growth and productivity under climate change conditions promoted by elevated GHG. Moreover, we also emphasise the need of extensive study on the interactive effects of major global change factors on AOX respiration and the importance of studies differentiating between the roles of AOX in sink versus source tissues under field conditions in order to improve plant productivity in response to elevated GHG.