Biogenic zinc titanate nanoparticles in plant tissue culture: micropropagation of Clitoria ternatea and molecular docking against pathogens

Abstract

Growing population, erratic weather, and resistant pathogens have created an urgent need for innovative strategies to enhance agricultural sustainability. To this effect, we have synthesized ZnTiO₃ nanoparticles in a green co-precipitation route using Vitex negundo L. leaf extract and assessed their efficiency in promoting the seedling growth of forage plant Clitoria ternatea. The synthesized nanoparticles were extensively characterized using UV-visible spectroscopy, FTIR, PL, XRD, SEM, EDAX and TEM. Plant tissue culture experiments with varying nanoparticle concentrations (1–5 mg mL⁻¹) revealed that 3 mg mL⁻¹ ZnTiO₃ nanoparticles significantly promoted root and shoot elongation, while higher concentrations inhibited growth. Single-particle ICP-MS analysis also confirmed the enhanced growth at 3 mg mL⁻¹. These results were further validated statistically using ANOVA, which revealed that exposure time and concentration were the primary determinants for shoot length. The nanoparticles also exhibited pronounced antifungal activity against the plant pathogens, Fusarium solani and Curvularia lunata, corroborated by molecular docking results indicating high binding energy (−8.6 kcal mol⁻¹) between fungal proteins and vitexin-capped ZnTiO₃ nanoparticles. The antifungal activity was further tested in a practical setting wherein these nanoparticles were introduced into a contaminated medium and they still retained their efficacy. Efficient seedling growth at this concentration matched with hardening-off results, where gradual acclimatization improved post-transplant growth. Thus, ZnTiO₃ nanoparticles proved to be a novel, nutrient-rich and microbial contamination resistant supplement which promotes the sustainable in vitro seedling growth of the C. ternatea plant.