Foliar Zinc Oxide Nanoparticles Enhanced Cannabinoid Biosynthesis in Leaves via THCA and CBDA Synthase Gene Upregulation in Cannabis sativa

This study demonstrates that foliar application of zinc oxide nanoparticles (ZnO NPs) enhances cannabinoid biosynthesis in Cannabis sativa leaf tissues through transcriptional upregulation of key synthases. Treatment with ZnO NPs (20–300 mg/L) significantly increased expression of tetrahydrocannabinolic acid synthase (THCAS) and cannabidiolic acid synthase (CBDAS) genes in a dose- and time-dependent manner. Consequently, metabolite levels of tetrahydrocannabinol (THC) and cannabidiol (CBD) were elevated, with maximal increases observed at 300 mg/L after extended exposure. These findings establish ZnO NPs as a potent biochemical elicitor for improving medicinal cannabis yield via targeted gene regulation.