Use of molecular ratios to identify changes in fatty acid composition of Miscanthus × giganteus (Greef et Deu.) plant tissue, rhizosphere and root-free soil during a laboratory experiment

► Fatty acid composition of Miscanthus tissues changes in the short term with growth. ► Differentiation of Miscanthus root and shoot biomass using ACL and CPI values. ► Molecular proxies reveal changes in plant and microbial FAs in soil and rhizosphere. ► Root-derived FAs were more strongly enriched (30-75%) in rhizosphere than bulk soil.