Nettle-induced metabolic changes in chive microgreens: first characterization of polyamine composition

Chives (Allium schoenoprasum L.) microgreens are emerging as functional foods, yet data on their polyamine composition remain scarce. This study reports, for the first time, the polyamine profile of chive microgreens cultivated under natural treatments, including distilled water and nettle (Urtica dioica L.) extract. Polyamine analysis revealed the presence of putrescine (PUT), spermidine (SPD), and spermine (SPM), with concentrations significantly influenced by the applied nettle extract treatments. PUT was the predominant polyamine, ranging from 1305.00 to 1857.91 nmol g^-1 DW. Nettle extract modulated polyamine accumulation in a concentration-dependent -manner, with 8 mg/mL producing the highest PUT concentration (1857.91 nmol g^-1 DW), while 160 mg/mL markedly reduced all quantified polyamines. These results indicate the potential of nettle extract as a natural biostimulant influencing nitrogen-related metabolic pathways in chive microgreens. The findings provide novel insight into the polyamine profiling of chives microgreens and -support their potential nutritional relevance.