OsDUF2488 acts synergistically with OsPrx1.1, regulates ROS metabolism and promotes dehydration tolerance in rice

Stress-mediated regulation of energy metabolism and its relation to plant adaptation remain largely unknown. Mitochondrial redox potential is greatly influenced by stress-induced reactive oxygen species (ROS); therefore, we mapped the dehydration-induced alterations in the mitochondrial proteome of a resilient rice cultivar, Rasi, generating a proteome map representing the largest inventory of dehydration-responsive mitochondrial proteins from any plant species. Quantitative proteomic analysis led to the identification of an array of dehydration-responsive proteins (DRPs), associated with various cellular functions, conceivably impinging on the molecular mechanism of adaptation. One DRP identified in the mitochondrial proteome was yeast cadmium factor 54 (YCF54-like), also known as DUF (domain of unknown function) and hereafter referred to as OsDUF2488. We demonstrated that OsDUF2488 localises to mitochondria and preferentially interacts with peroxiredoxin, OsPrx1.1. Overexpression of OsDUF2488 in rice caused enhanced tolerance to dehydration and oxidative stress, while CRISPR/Cas9 knockout mutants of OsDUF2488 showed hypersensitivity to dehydration. Upon exposure to dehydration, OsDUF2488 could rescue mitochondrial dysfunction, contributing to increased ATP production in OsDUF2488-overexpressing rice. Coexpression of OsDUF2488 and OsPrx1.1 in yeast demonstrated a mutual effect on enhanced ROS catabolism, suggesting a cross-kingdom adaptive response of OsDUF2488. Our findings suggest that OsDUF2488 acts synergistically with OsPrx1.1 to regulate redox homeostasis and promote stress tolerance in rice.