Plant viral infections threaten global food security and cause major crop losses. This study investigates the antiviral effects of biosynthesized Chitosan nanoparticles (ChNPs) with Bacillus subtilis 1211 EMCCN against potato virus Y (PVY) and their influence on tomato growth and yield.
Scanning electron microscopy showed clusters of crystals on ChNPs, while transmission electron microscopy revealed that the nanoparticles were spherical, ranging from 12 to 198 nm. Energy-dispersive X-ray spectroscopy confirmed the presence of carbon, oxygen, sodium, and phosphorus, and Fourier-transform infrared analysis identified typical chitosan functional groups, including hydroxyl, carbonyl, and amine. Tomato leaves were treated with ChNPs, B. subtilis, or both to evaluate their effectiveness against PVY. The treated plants exhibited a marked reduction in both disease severity and PVY concentration compared to the untreated controls. By 28 days post-inoculation, infectivity decreased to 46.7% in plants treated with Bacillus subtilis, 33.3% with ChNPs, and reached the lowest level of 20% in the combined treatment. The combined priming strategy significantly enhanced plant growth attributes, with increases in shoot length (95.0%), root length (47.0%), leaf area (668.1%), plant height (30.7%), shoot and root fresh weight (370.0% and 162.9%), and shoot and root dry weight (562.7% and 127.7%). Biochemical and physiological analyses revealed substantial increases in total pigments (268.4%), flavonoids (112.2%), phenols (59.4%), α-tocopherol (92.1%), ascorbic acid (30.1%), anthocyanins (71.3%), peroxidase (51.9%), catalase (39.6%), polyphenol oxidase (73.6%), amino acids (119.9%), proline (93.3%), soluble sugars (128.0%), and proteins (614.0%) in shoots. Yield components, including carotenoids and anthocyanins, were also significantly enhanced. Importantly, oxidative stress indicators were markedly reduced, with malondialdehyde and hydrogen peroxide levels decreasing by 76.8% and 72.6%, respectively, in treated plants compared to infected plants.
These findings suggest that combination between ChNPs and B. subtilis offers an eco-friendly method to enhance tomato yield and effectively manage viral diseases by activating the plants' defense mechanisms.
Ghanaim, A.M., Mahmoud, G.A., Mohamed, H.I. et al. Bacillus subtilis and chitosan nanoparticles enhance potato virus Y (PVY) tolerance in tomato (Solanum lycopersicum L.) via modulation of antioxidants and secondary metabolites. BMC Plant Biol 25, 1613 (2025). https://doi.org/10.1186/s12870-025-07617-0
Source: BMC Plant Biology
