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Field Density Variation and Metabolite Profiling Reveal Transcriptome Mechanisms Driving Salt-Responsive Root Flavone Accumulation in Scutellaria baicalensis

Year: 2026

Type: article

Abstract: Medicinal quality of Scutellaria baicalensis Georgi is decided by baicalin and wogonoside in root. In arid and semi-arid regions this crop is grown, salinized soils constrain establishment but reshape specialized metabolism. We used field density trials, salt-stress experiments, UPLC-MS/MS and time-series RNA-seq to ask whether agronomic practices and salt-induced transcriptional changes alter root flavone content. Planting density showed a clear yield-quality trade-off: higher density increased belowground biomass per unit area but reduced individual root growth and flavone content, with 100,000 plants mu-1 providing a practical balance between population yield and root quality under the tested Xinjiang field conditions. In established seedlings, 0.5% NaCl caused no visible damage over 24 h and specifically raised baicalin and baicalein at 12 h, while wogonin-type flavones remained nearly unchanged. Time-series RNA-seq identified thousands of differentially expressed genes between 2 and 24 h. WGCNA identified a turquoise module that was overrepresented with genes for carbohydrate metabolism and cytoskeletal/microtubule processes. Salt-responsive NAC, MYB and WRKY transcription factors co-expressed with core structural genes (PAL, 4CL, CHS, CHI); one candidate, SbNAC076, was up-regulated mainly at 24 h after the metabolite peak, consistent with a role in sustaining rather than triggering accumulation. These findings outline the temporal dynamics of salt-induced branch-selective flavone accumulation and suggest candidate regulators for functional validation, with implications for quality-focused cultivation on saline marginal lands.

Source: International Journal of Molecular Sciences

DOI: 10.3390/ijms27208996