Nucleoside Diphosphate Kinase Family: Evolutionary Analysis and Protective Role in Mitochondrial ROS Production.

Area of Science:

• Plant molecular biology
• Evolutionary biology
• Biochemistry

Background:

• Nucleoside diphosphate kinase (NDPK) is vital for cellular nucleotide balance.
• Its evolutionary path and functional adaptations in plants, particularly Solanaceae, require further investigation.

Purpose of the Study:

• To investigate the evolution of NDPK across plant species, focusing on the Solanaceae family.
• To understand the relationship between NDPK's evolutionary history and its diverse cellular functions.
• To elucidate the role of mitochondrial NDPK in plant cellular processes.

Main Methods:

• Phylogenetic and molecular dating analyses to trace NDPK evolution.
• Functional assays using isolated potato tuber mitochondria.
• Analysis of mitochondrial membrane potential and reactive oxygen species (ROS) production.
• Gene expression analysis of mitochondrial NDPK during tuber development.

Main Results:

• NDPK group 1 and 2 divergence predates plant-animal divergence; plant-specific types originated early in streptophyte evolution.
• Solanaceae species possess conserved NDPK genes, including a mitochondrial type III isoform.
• Mitochondrial NDPK is active in the intermembrane space, supporting oxidative phosphorylation and reducing ROS production.
• Activation of mitochondrial NDPK suppressed ROS and altered mitochondrial membrane potential, with GDP and UDP showing preferential phosphorylation.

Conclusions:

• NDPKs exhibit evolutionary conservation alongside functional diversification in plants.
• Mitochondrial NDPK acts as a key regulator of mitochondrial redox homeostasis.
• This study reveals an antioxidant mechanism integrating plant mitochondrial energy metabolism with development and stress responses.