Gamma irradiation shapes high value metabolite responses across microbes microalgae and plants

Gamma irradiation can function either as an acute physical elicitor that alters redox and metabolic regulation or as a mutagen that generates selectable genetic variation. We compared evidence from bacteria, fungi, microalgae, plants, and plant cell systems using a common framework that links absorbed dose and exposure context to response mode, evidence strength, phenotype stability, and productivity. Across these systems, irradiation can increase metabolite accumulation or support recovery of improved strains and lines, but responses remain strongly dependent on biological material, dosimetry, selection, and cultivation conditions. Heterogeneous dose reporting, inconsistent productivity denominators, limited causal validation, and scarce scale-up data prevent definition of a universal effective dose or mechanism. We therefore distinguish concentration from total yield and volumetric productivity and propose a stage-gated workflow integrating dosimetry, molecular characterization, stability testing, bioprocess evaluation, and safety and economic assessment to support defensible translation.