Bacterial wilt of potato (Solanum tuberosum L.) is a devastating disease among potato crops across the world caused by soil-borne bacterium Ralstonia solanacearum, which leads to substantial economic and agricultural losses. The current study aimed to evaluate the antibacterial activity of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) on R. solanacearum in in-vitro conditions. In vitro disc diffusion method revealed that out of five different concentrations of AgNPs and AuNPs, 5000 ppm causes the highest inhibition zone (mm) of 1.70 mm and 1.45 mm of R. solanacearum, respectively. Scanning Electron Microscope (SEM) analysis showed that these nanoparticles cause distortion of bacterial cell walls. Mode of action of AgNPs and AuNPs triggers the overproduction of superoxide radicals within bacteria leading to oxidative stress and structural damage that causes the disruption of cellular homeostasis, effectively killing the bacterium.
Raj, R., Vanlaltani, L., Mahanta, M., Singh, H., Das, P., Raj, R., Dutta, P., 2025. Comparative evaluation of silver and gold nanoparticles for the management of bacterial wilt of potato caused by Ralstonia solanacearum. Research Biotica 7(1), 05-10. DOI: 10.54083/ResBio/7.1.2025/05-10.
AgNPs, AuNPs, Nanoparticles (NPs), R. solanacearum, Scanning Electron Microscope (SEM)
Chaudhry, Z., Rashid, H., 2011. Isolation and characterization of Ralstonia solanacearum from infected tomato plants of Soan Skesar Valley of Punjab. Pakistan Journal of Botany 43(6), 2979-2985.
Das, A., Dutta, P., 2021. Antifungal activity of biogenically synthesized silver and gold nanoparticles against sheath blight of rice. Journal of Nanoscience and Nanotechnology 21(6), 3547-3555. DOI: https://doi.org/10.1166/jnn.2021.18996.
Dilbar, S., Sher, H., Ali, H., Ullah, R., Ali, A., Ullah, Z., 2023. Antibacterial efficacy of green synthesized silver nanoparticles using salvia nubicola extract against Ralstonia solanacearum, the causal agent of vascular wilt of tomato. ACS Omega 8(34), 31155-31167. DOI: https://doi.org/10.1021/acsomega.3c03164.
Feng, Q.L., Wu, J., Chen, G.Q., Cui, F.Z., Kim, T.N., Kim, J.O., 2000. A mechanistic study of the antibacterial effect of silver ions on Escherichia coli and Staphylococcus aureus. Journal of Biomedical Materials Research 52(4), 662-668. DOI: https://doi.org/10.1002/1097-4636(20001215)52:4%3C662::AID-JBM10%3E3.0.CO;2-3.
Gupta, A., Matsui, K., Lo, J.F., Silver, S., 1999. Molecular basis for resistance to silver cations in Salmonella. Nature Medicine 5(2), 183-188. DOI: https://doi.org/10.1038/5545.
Gurunathan, S., Kalishwaralal, K., Vaidyanathan, R., Deepak, V., Pandian, S.R.K., Muniyandi, J., Hariharan, N., Eom, S.H., 2009. Biosynthesis, purification and characterization of silver nanoparticles using Escherichia coli. Colloids and Surfaces B: Biointerfaces 74(1), 328-335. DOI: https://doi.org/10.1016/j.colsurfb.2009.07.048.
Hovhannisyan, A., Janik, M., Woszczak, L., Khachatryan, G., Krystyjan, M., Lenart-Boroń, A., Stankiewicz, K., Czernecka, N., Duraczyńska, D., Oszczęda, Z., Khachatryan, K., 2023. The preparation of silver and gold nanoparticles in hyaluronic acid and the influence of low-pressure plasma treatment on their physicochemical and microbiological properties. International Journal of Molecular Sciences 24(24), 17285. DOI: https://doi.org/10.3390/ijms242417285.
Javvaji, P.K., Dhali, A., Francis, J.R., Kolte, A.P., Mech, A., Roy, S.C., Mishra, A., Bhatta, R., 2020. An efficient Nitroblue Tetrazolium staining and bright-field microscopy-based method for detecting and quantifying intracellular reactive oxygen species in oocytes, cumulus cells and embryos. Frontiers in Cell and Developmental Biology 8, 764. DOI: https://doi.org/10.3389/fcell.2020.00764.
Kelman, A., 1954. The relationship of pathogenicity in Pseudomonas solanacearum to colony appearance on a tetrazolium medium. Phytopathology 115(8V), 693-695. DOI: https://doi.org/10.1094/Phyto-44-693.
Kharumnuid, P., Rao, I.S., Sudharani, V., 2020. Factors influencing adaptation to climate change: Evidence from potato growers of Meghalaya state in North East India. Journal of Entomology and Zoology Studies 8(3), 1336-1341.
Khetmalas, M.B., 1984. Studies on wilt of groundnut (Arachis hypogaea L.) caused by Pseudomonas solanacearum. M.Sc. Agri. Thesis, Dept. of Plant Pathology, Konkan Krishi Vidyapeeth, Dapoli, India. p. 145.
Kim, J.S., Kuk, E., Yu, K.N., Kim, J.H., Park, S.J., Lee, H.J., Kim, S.H., Park, Y.K., Park, Y.H., Hwang, C.Y., Kim, Y.K., Lee, Y.S., Jeong, D.H., Cho, M.H., 2007. Antimicrobial effects of silver nanoparticles. Nanomedicine: Nanotechnology, Biology and Medicine 3(1), 95-101. DOI: https://doi.org/10.1016/j.nano.2006.12.001.
Klement, Z., 1990. Tobacco (HR) test for the quick demonstration of pathogenicity. In: Methods in Phytobacteriology. (Eds.) Klement, Z., Rudolph, K. and Sands, D.C. Akadémiai Kiadó, Budapest. pp. 101-102.
Kumar, M., Baishya, L.K., Ghosh, D.C., Gupta, V.K., 2011. Yield and quality of potato (Solanum tuberosum) tubers as influenced by nutrient sources under rainfed condition of Meghalaya. Indian Journal of Agronomy 56(3), 260-266. DOI: https://doi.org/10.59797/ija.v56i3.4688.
Li, W.R., Xie, X.B., Shi, Q.S., Zeng, H.Y., Ou-Yang, Y.S., Chen, Y.B., 2010. Antibacterial activity and mechanism of silver nanoparticles on Escherichia coli. Applied Microbial and Cell Physiology 85(4), 1115-1122. DOI: https://doi.org/10.1007/s00253-009-2159-5.
Lok, C.N., Ho, C.M., Chen, R., He, Q.Y., Yu, W.Y., Sun, H., Tam, P.K.H., Chiu, J.F., Che, C.M., 2006. Proteomic analysis of the mode of antibacterial action of silver nanoparticles. Journal of Proteome Research 5(4), 916-924.DOI: https://doi.org/10.1021/pr0504079.
Murthy, K.N., Soumya, K., Udayashankar, A.C., Srinivas, C., Jogaiah, S., 2021. Biocontrol potential of plant growth-promoting rhizobacteria (PGPR) against Ralstonia solanacearum: Current and future prospects. In: Biocontrol Agents and Secondary Metabolites: Applications and Immunization for Plant Growth and Protection. (Ed.) Jogaiah, S. Woodhead Publishing. pp. 153-180. DOI: https://doi.org/10.1016/B978-0-12-822919-4.00007-7.
Rahman, M.F., Islam, M.R., Rahman, T., Meah, M.B., 2010. Biochemical characterization of Ralstonia solanacerum causing bacterial wilt of brinjal in Bangladesh. Progressive Agriculture 21(1-2), 9-19. DOI: https://doi.org/10.3329/pa.v21i1-2.16744.
Santiago, T.R., Bonatto, C.C., Rossato, M., Lopes, C.A.P., Lopes, C.A., Mizubuti, E.S.G., Silva, L.P., 2019. Green synthesis of silver nanoparticles using tomato leaf extract and their entrapment in chitosan nanoparticles to control bacterial wilt. Journal of the Science of Food and Agriculture 99(9), 4248-4259. DOI: https://doi.org/10.1002/jsfa.9656.
Sharma, P., Jha, A.B., Dubey, R.S., Pessarakli, M., 2012. Reactive oxygen species, oxidative damage and antioxidative defense mechanism in plants under stressful conditions. Journal of Botany 2012(1), 217037. DOI: https://doi.org/10.1155/2012/217037.
Tahat, M.M., Sijam, K., 2010. Ralstonia solanacearum: The bacterial wilt causal agent. Asian Journal of Plant Sciences 9(7), 385-393. DOI: https://doi.org/10.3923/ajps.2010.385.393.
Talarska, P., Boruczkowski, M., Żurawski, J., 2021. Current knowledge of silver and gold nanoparticles in laboratory research - Application, toxicity, cellular uptake. Nanomaterials 11(9), 2454. DOI: https://doi.org/10.3390/nano11092454.
Tendencia, E.A., 2004. Disk diffusion method. In: Laboratory Manual of Standardized Methods for Antimicrobial Sensitivity Tests for Bacteria Isolated from Aquatic Animals and Environment. (Eds.) Ruangpan, L. and Tendencia, E.A. Aquaculture Extension Manual No. 37. Southeast Asian Fisheries Development Center, Aquaculture Department, Tigbauan, Iloilo, Philippines. pp. 13-29.
