# Graphitic Carbon Nitride as a Nanostimulant in Basil Microgreens: Insights into Growth, Flavonoid Content, and Water Stress Response

## TL;DR

This study shows that graphitic carbon nitride can boost basil microgreen growth and flavonoid content, even under water stress.

## Contribution

The paper introduces graphitic carbon nitride as a nanostimulant for enhancing plant stress tolerance and secondary metabolite production.

## Key findings

- g-C3N4 increased leaf area by 34% under water stress at 100 mg L–1.
- Flavonoid content rose by 49.98% and 42.87% at 100 and 200 mg L–1 under water stress.
- g-C3N4 modulated physiological responses to enhance stress tolerance in basil microgreens.

## Abstract

Graphitic carbon
nitride (g-C3N4) exhibits
strong adsorption and photocatalytic activity through reactive oxygen
species generation, which also mediate plant stress responses. This
study evaluated the effects of g-C3N4 on growth
and secondary metabolites in basil (Ocimum basilicum L.) microgreens under water deficit. The nanomaterial was synthesized
by calcination and characterized by X-ray diffraction (XRD), Fourier-transform
infrared (FTIR), transmission electron microscopy (TEM), scanning
electron microscopy-energy dispersive spectroscopy (SEM-EDS), and
dynamic light scattering-electrophoretic light scattering (DLS-ELS).
Plants were grown under two hydration regimes (50 and 100% water replacement)
and five g-C3N4 concentrations (0–250
mg L–1). Foliar applications were performed at 7
and 14 days after sowing, and plants were harvested at day 21. Under
50% water replacement, g-C3N4 enhanced growth,
increasing leaf area by 34% at 100 mg L–1, stem
length by 23 and 19% at 50 and 100 mg L–1, respectively,
and root length by 17% at 250 mg L–1 compared to
the untreated control. Terpenoid profiles remained unchanged, while
flavonoid content increased by 49.98% and 42.87% at 100 and 200 mg
L–1, respectively, under water stress. Overall,
g-C3N4 acted as a modulator of physiological
responses, enhancing stress tolerance in basil microgreens.