GA₃ synchronously enhances rhizome biomass and bioactive compound accumulation in Rhodiola crenulata through coordinated metabolic reprogramming

Rhodiola crenulata is a rare functional food plant whose utilization is limited by extremely slow rhizome growth. The role of gibberellic acid (GA 3 ) in coordinating biomass production and bioactive compound accumulation remains unclear. Here, integrated morphological, physiological, metabolomic, and transcriptomic analyses were used to elucidate the effects of exogenous GA 3 on rhizome yield and quality. GA 3 significantly promoted shoot and root growth by increasing leaf area, enhancing chloroplast development, and stimulating rhizome cell division and enlargement. It also increased leaf starch and soluble protein contents while suppressing α-amylase and sucrose-metabolizing enzyme activities, favoring assimilate accumulation. Multi-omics analyses identified 437 differentially accumulated metabolites and 3241 differentially expressed genes. GA 3 enhanced carbon fixation while repressing phenylpropanoid biosynthesis, and was associated with increased DDC expression, potentially promoting tyrosine flux toward salidroside and tyrosol biosynthesis. Overall, GA 3 synchronously improves rhizome biomass and functional quality through coordinated metabolic reprogramming.