Raw data supporting the findings of my study

d nanocomposites (Si–SA NCS), can alleviate lead (Pb) toxicity in Italian basil (Ocimum basilicum L.) by improving growth, physiological status, mineral balance, antioxidant activity, and essential oil quality. It was further hypothesized that the combined Si–SA treatment would be more effective than individual applications under Pb stress.

The dataset was obtained from a controlled greenhouse pot experiment with a factorial design including two Pb levels (with and without Pb stress) and four treatments: control, silicon (Si), salicylic acid (SA), and Si–SA nanocomposites. Soil physicochemical properties were analyzed prior to planting. Morphological traits (plant height, root length, leaf number, and leaf area), biomass production (fresh and dry weights of roots, stems, leaves, and whole plant), and physiological indices (specific leaf area, specific leaf weight, relative water content, and membrane stability index) were measured using standard methods.

The dataset also includes measurements of photosynthetic pigments, mineral accumulation (Pb, Si, Ca, and K), antioxidant enzyme activities (GPOX, PPO, CAT, and APX), and bioactive compounds (phenolics, flavonoids, DPPH radical scavenging activity, essential oil content, and yield). Essential oil composition was determined by GC–MS analysis. Physicochemical characterization of the synthesized Si–SA nanocomposites was performed using zeta potential, DLS, FTIR, and TEM analyses.

Data were statistically analyzed using analysis of variance (ANOVA) followed by Duncan’s multiple range test, and multivariate analyses (PCA and correlation heatmap) were used to interpret relationships among traits. The dataset demonstrates that Pb stress negatively affects growth and physiological performance, while Si and SA treatments—especially Si–SA nanocomposites—significantly mitigate Pb-induced damage. The data can be used to interpret stress-alleviation mechanisms and for comparative or meta-analytical studies.