Optimization of 14C liquid scintillation counting of plant and soil lipids to trace short term formation, translocation and degradation of lipids

Abstract

Two powerful approaches are frequently used to trace incorporation and degradation of plant derived C in soil: 14C labelling/chasing and analysis of lipid composition. In this study, we coupled these approaches in order to trace short term incorporation of plant derived lipids into rhizosphere and non-rhizosphere soil. Methodological optimization was required and implied 14C liquid scintillation counting improvement for plant lipid extracts taking into account organic solvents, solvent-to-scintillation cocktail ratio, and amount of lipids. Following method optimization, 14C data of fatty acids indicated a notable contribution of root derived lipids to rhizosphere and non-rhizosphere soil. Coupling of 14C labelling/chasing with lipid analysis is a powerful and cheap approach for tracing of root derived C in soil allowing for estimation of C budget, for determination of C formation and translocation within plants and from plant to soil, as well as for identification of short term dynamics of specific compound classes within soil.