Culture medium and plant growth regulator regimes influence the transcriptome and cannabisin accumulation in Cannabis sativa cell suspension cultures.

Plant cell suspension cultures are a valuable biotechnological platform for the controlled production of high-value phytochemicals. Yet, the molecular mechanisms by which culture medium composition impacts cellular transcriptional programs remain poorly characterised, especially in non-model plant species. Here, we investigated how two culture media, Murashige & Skoog (MS)- and Linsmaier & Skoog (LS)-based, influence growth, gene expression and secondary metabolite production in Cannabis sativa cell suspension cultures derived from a non-commercial genotype, Line 43/178. Cultures were analysed at five time points across a 14-day subculture cycle. Both media supported comparable growth kinetics, with a peak in biomass production reaching values ≥13 g/L dry weight. Transcriptomic analysis identified 2801 differentially expressed contigs with an absolute maximum fold change >10 and revealed distinct growth-stage responses, including early activation of cell cycle and hormone-related genes, intermediate induction of stress and cell wall remodelling pathways and late-stage senescence and redox-related processes. LS induced the expression of genes involved in hydroxycinnamic acid amide and lignanamide production, in agreement with untargeted metabolomic data showing increased accumulation of cannabisin D and cannabisin F, together with marked differences in cell morphology. Spectrophotometric analyses further revealed medium-dependent differences in total phenolic content and antioxidant activity. By adopting a transcriptomic approach coupled to the identification of lignanamides via untargeted metabolomics, the study highlights how medium composition regulates the balance between growth and secondary metabolism in C. sativa cell cultures, providing valuable insights for future optimisation of bioactive compound production using plant cell factories.