Nanopriming with Spirulina carbon dots boosts translation, metabolism, and ion homeostasis in rice seedlings

ABSTRACT: Biogenic carbon dots (CDs) are emerging plant biostimulants, yet their effects during early crop establishment remain underexplored. Here, we synthesize and characterize Spirulina-derived CDs and test their performance as seed nanopriming agents in rice. The CDs showed nanoscale dimensions and abundant surface functionalities, with Raman/FTIR features consistent with graphitic-amorphous carbon and a highly negative ζ-potential, indicative of stable dispersions. Near-infrared spectroscopy with PCA resolved time-dependent metabolic changes during imbibition and identified 8-12 h as an optimal priming window. At 0.2 mg mL-1 for 12 h, Spirulina nanopriming increased seed germination rate (25%), germination speed index (17%), vigor index I (22%), and root length (37%) relative to hydropriming. Additionally, nanoprimed seedlings accumulated more starch (24%) and total carbohydrates (8%), and exhibited higher total phenolics (20%) than hydroprimed seedlings, without evidence of oxidative imbalance. Proteomic profiling revealed coordinated reprogramming: Spirulina nanopriming selectively boosted pathways for protein synthesis, energy production, and ion/nutrient homeostasis, while pathways for reserve breakdown and constitutive defense declined, indicating a shift from stress-biased to growth-oriented metabolism. Collectively, Spirulina-derived CDs act as effective nanobiostimulants that couple early metabolic activation with nutrient mobilization, offering a practical route to strengthen rice seedling establishment.

INSTRUMENT(S):

ORGANISM(S): Oryza Sativa (rice)

TISSUE(S): Plant Cell, Seedling

SUBMITTER: Vanildo Silveira  

LAB HEAD: Raul Antonio Sperotto

PROVIDER: PXD069738 | Pride | 2026-08-17

REPOSITORIES: Pride