Quantitative Dynamic Analysis ofde novoSphingolipid Biosynthesis inArabidopsis thaliana

Abstract

SummarySphingolipids are pivotal for plant development and stress responses. Growing interest has been directed towards fully comprehending the regulatory mechanisms of the sphingolipid pathway. We explore itsde novobiosynthesis and homeostasis inArabidopsis thalianacell cultures, shedding light on fundamental metabolic mechanisms. Employing15N isotope labeling and quantitative dynamic modeling approach, we developed aregularized and constraint-basedDynamicMetabolicFluxAnalysis (r-DMFA) framework to predict metabolic shifts due to enzymatic changes. Our analysis revealed key enzymes such as sphingoid-base hydroxylase (SBH) and long-chain-base kinase (LCBK) to be critical for maintaining sphingolipid homeostasis. Disruptions in these enzymes were found to affect cellular viability and increase the potential for programmed cell death (PCD). Thus, this work enhances our understanding of sphingolipid metabolism and demonstrates the utility of dynamic modeling in analyzing complex metabolic pathways.