Investigation of NADPH-Dependent Thioredoxin Reductase-C (NTRC) In Chloroplast Lipid Metabolism

Abstract

Redox reactions are ubiquitous within plant metabolism and critical for the sustainment of photosynthesis within thylakoid membranes. Specialized glycerolipids that make up these membranes in turn require redox reactions for the synthesis and modification of their fatty acyl chains. Previous research has shown that plants subjected to oxidative stress (e.g., high light) often exhibit conditions associated with an unbalanced flow of electrons coupled with changes in lipid metabolism ad structure. However, it remains unclear how chloroplast membranes are impacted and subsequently repair their membranes to maintain photosynthesis. This project explores the potential role of NADPH-Dependent Thioredoxin Reductase-C (NTRC), a reactive oxygen species (ROS)-scavenging enzyme, in chloroplast lipid metabolism. NTRC has been implicated in many diverse pathways; however, ntrc also displays an altered lipid phenotype that has yet to be investigated. We are beginning to understand how the photosynthetically starved state of ntrc mutants reacts with the additional loss of key lipids through development of higher order ntrc mutants. We have characterized these novel mutants, in addition to their single mutant parents, through measurements of growth and photosynthetic parameters, lipid profiles, and lipid stress-recovery assays. Ultimately, we predict that through an improved understanding of chloroplast membrane dynamics our results can inform engineering strategies that target enhanced plant resilience subjected to adverse environmental conditions.