Foliar concentrations of plant secondary metabolites (PSMs) are influenced by soil water availability. However, concentrations of individual compounds in previously published studies have been reported to be higher, lower or to remain stable during water deficit.
McKiernan et al. use multiple levels of continuous water deficit to test the effect on plant stress levels, growth and PSM concentrations in potted Eucalyptus globulus. Quantifying a range of terpene and phenolic compounds extracted from leaves reveals that PSM concentrations remain largely stable even in highly stressed or dead plants. Dead E. globulus exhibited decreased foliar total oil concentration.