The study developed a validated LC‑MS/MS method to simultaneously quantify fourteen polyamines, amino acids, and ethylene precursors in Arabidopsis thaliana and Solanum lycopersicum, and used it to compare their metabolic responses to drought, salinity, and inhibitor treatments. Distinct species‑specific metabolic adjustments were observed, with Arabidopsis showing greater fluctuations and drought generally increasing metabolite levels, while spermine exhibited stress‑specific patterns.

The study investigated whether nitrogen‑fixing rhizobial symbiosis in Medicago truncatula primes defense against the pea aphid Acyrthosiphon pisum. Metabolite profiling (LC‑MS, GC‑MS) and qPCR revealed that symbiotic plants uniquely accumulated triterpenoid saponins and up‑regulated flavonoid‑biosynthetic genes after aphid infestation, suggesting that NFS enhances pest‑specific defenses.