Comparative Effects of Nano-Silicon Application Methods on Salt Stress Tolerance in Lettuce (Lactuca sativa L.)

Abstract

The aim of this study was to evaluate the effectiveness of different doses and application methods of nano-silicon (Nano-Si) in enhancing salt tolerance in lettuce (Lactuca sativa L.) and to determine the most effective treatment under saline conditions. The curly lettuce cultivar Caipira (Şakira) (Batavia type) was used as the plant material. Salt stress was imposed by applying 100 mM NaCl 20 d after transplantation. Nano-Si was applied weekly at doses of 0, 0.5, 1.0, 2.0, and 3.0 mM using two different methods, foliar spraying and root drenching. At harvest, plants were evaluated for shoot fresh and dry weights, plant height, plant circumference, crown width, root collar diameter, leaf area, total yield, relative water content (RWC), shoot Na⁺, Cl⁻, K⁺, and Ca²⁺ concentrations, malondialdehyde (MDA), total chlorophyll, and carotenoid contents. Salt stress significantly reduced growth parameters, total yield, RWC, K⁺ and Ca²⁺ concentrations, and photosynthetic pigment content, whereas it increased Na⁺ and Cl⁻ accumulation and MDA levels. In contrast, Nano-Si applications markedly improved plant performance under salt stress. Compared with salt stress alone, Nano-Si treatments increased fresh and dry weights by 37-286%, plant height and root collar diameter by 5-46%, plant circumference and crown width by 6-91%, leaf area by 100-271%, total yield by 74-219%, RWC by 16-56%, K⁺ content by 24-57%, Ca²⁺ content by 56-164%, and photosynthetic pigments by 15-126%. Furthermore, Nano-Si applications reduced Na⁺ uptake by 13-47% and Cl⁻ uptake by 1-40%, while decreasing MDA accumulation by 5-55%. Overall, Nano-Si effectively mitigated the detrimental effects of salt stress and enhanced the salt tolerance of lettuce. Among the treatments, foliar applications of 0.5 and 1.0 mM Nano-Si were the most effective and can be recommended as a promising strategy for improving lettuce performance under saline conditions.

Keywords

• Foliar application
• ion homeostasis
• lipid peroxidation
• relative water content
• root drench
• sodium chloride

References

1. Alam, P., Arshad, M., Al-Kheraif, A.A., Azzam, M.A., Al Balawi, T., 2022. Silicon nanoparticle-induced regulation of carbohydrate metabolism, photosynthesis, and ros homeostasis in Solanum lycopersicum subjected to salinity stress. American Chemical Society Omega, 7(36): 31834-31844.
2. Alsaeedi, A., El-Ramady, H., Alshaal, T., El-Garawany, M., Elhawat, N., Al-Otaibi, A., 2019. Silica nanoparticles boost growth and productivity of cucumber under water deficit and salinity stresses by balancing nutrients uptake. Plant Physiology and Biochemistry, 139: 1-10.
3. Arif, Y., Singh, P., Siddiqui, H., Bajguz, A., Hayat, S., 2020. Salinity induced physiological and biochemical changes in plants: An omic approach towards salt stress tolerance. Plant Physiology and Biochemistry, 156: 64-77.
4. Atta, K., Mondal, S., Gorai, S., Singh, A.P., Kumari, A., Ghosh, T., Roy, S., Sarker, U., Brestic, M., Skalicky, M., Hossain, A., Brestic, M., 2023. Impacts of salinity stress on crop plants: Improving salt tolerance through genetic and molecular dissection. Frontiers in Plant Science, 14: 1241736.
5. Avestan, S., Ghasemnezhad, M., Esfahani, M., Byrt, C.S., 2019. Application of nano-silicon dioxide improves salt stress tolerance in strawberry plants. Agronomy, 9(5): 246.
6. Barassi, C.A., Ayrault, G., Creus, C.M., Sueldo, R.J., Sobrero, M.T., 2006. Seed inoculation with Azospirillum mitigates NaCl effects on lettuce. Scientia Horticulturae, 109(1): 8-14.
7. Bayram, M., Dere, S., Arpacı, B.B., Daşgan, Y., 2021. Multiple stress factors and plant responses in vegetables. In: Ş.Ş. Ellialtıoğlu, H.Y. Daşgan and Ş. Kuşvuran (Eds.), Stress Tolerance and Breeding Strategies in Vegetables, Gece Kitaplığı, Ankara, Türkiye, pp: 277-311. (In Turkish).
8. Cakmakci, O., Sensoy, S., 2025. Nano-silica modulates salt stress response in lettuce by enhancing growth, antioxidant activity, and mineral uptake. Plant, Soil and Environment, 71(8): 553-564.

9. Dasgan, H.Y., Koc, S., 2009. Evaluation of salt tolerance in common bean genotypes by ion regulation and searching for screening parameters. Journal of Food, Agriculture Environment, 7(2): 363-372.
10. Derosa, M.C., Monreal, C., Schnitzer, M., Walsh, R., Sultan, Y., 2010. Nanotechnology in fertilizers. Nature Nanotechnology, 5(2): 91-91.
11. El-Ramady, H., Verma, K.K., Rajput, V.D., Minkina, T., Elbehery, F., Elbasiony, H., Amer, M., 2022. Sources of silicon and nano-silicon in soils and plants. In: H. Etesami, A. Al Saeedi, H. El-Ramady, M. Fujita, M. Pessarakli and M.A. Hossain (Eds.), Silicon and Nano-silicon in Environmental Stress Management and Crop Quality Improvement, Academic Press, United Kingdom, pp. 1-10.
12. Farhangi-Abriz, S., Torabian, S., 2018. Nano-silicon alters antioxidant activities of soybean seedlings under salt toxicity. Protoplasma, 255(3): 953-962.
13. Garrido, Y., Tudela, J.A., Marín, A., Mestre, T., Martínez, V., Gil, M.I., 2014. Physiological, phytochemical and structural changes of multi‐leaf lettuce caused by salt stress. Journal of the Science of Food and Agriculture, 94(8): 1592-1599.
14. Gong, Z., 2021. Plant abiotic stress: New insights into the factors that activate and modulate plant responses. Journal of Integrative Plant Biology, 63(3): 429.
15. Gözen, V., Kuşvuran, S., 2021. Low-temperature stress. In: Ş.Ş. Ellialtıoğlu, H.Y. Daşgan and Ş. Kuşvuran (Eds.), Stress Tolerance and Breeding Strategies in Vegetables, Gece Kitaplığı, Ankara, Türkiye, pp. 157-203. (In Turkish).
16. Haghighi, M., Pessarakli, M., 2013. Influence of silicon and nano-silicon on salinity tolerance of cherry tomatoes (Solanum lycopersicum L.) at early growth stage. Scientia Horticulturae, 161: 111-117.
17. Hung, H.C., Joshipura, K.J., Jiang, R., Hu, F.B., Hunter, D., Smith-Warner, S.A., Willett, W.C., 2004. Fruit and vegetable intake and risk of major chronic disease. Journal of the National Cancer Institute, 96(21): 1577-1584.
18. Ismail, L.M., Soliman, M.I., Abd El-Aziz, M.H., Abdel-Aziz, H.M., 2022. Impact of silica ions and nano silica on growth and productivity of pea plants under salinity stress. Plants, 11(4): 494.
19. Kalteh, M., Alipour, Z.T., Ashraf, S., Marashi Aliabadi, M., Falah Nosratabadi, A., 2014. Effect of silica nanoparticles on basil (Ocimum basilicum L.) under salinity stress. Journal of Chemical Health Risks, 4(3): 49-55.
20. Kusvuran, S., Dikmen Yılmaz, U., 2023. Ameliorative role of salicylic acid in the growth, nutrient content, and antioxidative responses of salt-stressed lettuce. Acta Scientiarum Polonorum Hortorum Cultus, 22(1): 75-85.
21. Kusvuran, S., Kıran, S., Altuntas, O., 2021. Influence of salt stress on different pepper genotypes: Ion homeostasis, antioxidant defense, and secondary metabolites. Global Journal of Botanical Science, 9: 14-20.
22. Lutts, S, Kinet, J.M., Bouharmont, J., 1996. NaCl-induced senesence in leaves of rice (Oryza sativa L.) cultivars differing in salinity resistance. Annals of Botany, 78(3): 389-398.
23. Merwad, A.R.M., Desoky, E.S.M., Rady, M.M., 2018. Response of water deficit-stressed Vigna unguiculata performances to silicon, proline or methionine foliar application. Scientia Horticulturae, 228: 132-144.
24. Mir, R.A., Bhat, B.A., Yousuf, H., Islam, S.T., Raza, A., Rizvi, M.A., Kumar, A., Zargar, S.M., 2022. Multidimensional role of silicon to activate resilient plant growth and to mitigate abiotic stress. Frontiers in Plant Science, 13: 1-26.
25. Ndiso, J.B., Chemining’wa, G.N., Olubayo, F.M., Saha, H.M., 2016. Effect of drought stress on canopy temperature, growth and yield performance of cowpea varieties. International Journal of Plant & Soil Science, 9(3): 1-12.
26. Nielsen, S.S., 2017. Sodium determination using ion-selective electrodes, Mohr titration, and test strips. In: S.S Nielsen (Ed.), Food Analysis Laboratory Manual (Third Edition), Springer, USA, pp. 161-170.
27. Özyazıcı, G., 2021. Effect of silicon appliacations on germination properties of fenugreek (Trigonella foenum-graecum L.) plant. 2nd International Baku Conference on Scientific Research, 28-30 April, Baku, Azerbaijan, pp. 485-494. (In Turkish).
28. Özyazıcı, G., 2022. Effect of silicon applications on germination properties of fennel (Foeniculum vulgare Mill.) genotypes. II. International Conference on Global Practice of Multidisciplinary Scientific Studies, 24-26 March, Ankara, Turkey, pp. 1628-1639. (In Turkish).
29. Parihar, P., Singh, S., Singh, R., Singh, V.P., Prasad, S.M., 2015. Effect of salinity stress on plants and its tolerance strategies: A review. Environmental Science and Pollution Research, 22(6): 4056-4075.
30. Rastogi, A., Tripathi, D.K., Yadav, S., Chauhan, D.K., Živčák, M., Ghorbanpour, M., Brestic, M., 2019. Application of silicon nanoparticles in agriculture. 3 Biotech, 9(3): 1-11.
31. Sanchez, F.J., Andres, E.F., TenorIo, J.L., Ayerbe, L., 2004. Growth of epicotyls, turgor maintenance and osmotic adjustment in pea plants (Pisum sativum L.) subjectedto water stres. Field Crops Research, 86(1): 81-90.
32. Sardar, H., Khalid, Z., Ahsan, M., Naz, S., Nawaz, A., Ahmad, R., Abou Fayssal, S., 2023. Enhancement of salinity stress tolerance in lettuce (Lactuca sativa L.) via foliar application of nitric oxide. Plants, 12(5): 1115.
33. Saxena, R., Tomar, R.S., Kumar, M., 2016. Exploring nanobiotechnology to mitigate abiotic stress in crop plants. Journal of Pharmaceutical Sciences and Research, 8(9): 974.
34. Siddiqi, K.S., Husen, A., Zahra, N., Moheman, A., 2025. Harnessing silicon nanoparticles and various forms of silicon for enhanced plant growth performance under salinity stress: Application and mechanism. Discover Nano, 20(89): 1-24.
35. Siddiqui, M.H., Al-Whaibi, M.H., Firoz, M., Al-Khaishany, M.Y., 2015. Role of salinity tolerance of sweet pepper plants. International Journal of ChemTech Research, 8(10): 11-17.
36. Simko, I., Zhao, R., Peng, H., 2025. Differential impact of SiO₂ foliar application on lettuce response to temperature, salinity, and drought stress. Plants, 14(12): 1-19.
37. Tilman, D., Clark, M., 2014. Global diets link environmental sustainability and human health. Nature, 515: 518-522.
38. Türkan, İ., Bor, M., Özdemir, F., Koca, H., 2005. Differantial responses of lipid peroxidation and antioxidants in the leaves of droutght-tolerant P. acutifolius gray and drought sensetive P. vulgaris L. subjected to polyethylene glycol mediates water stres. Plant Science, 168(1): 223-231.
39. Van Zelm, E., Zhang, Y., Testerink, C., 2020. Salt tolerance mechanisms of plants. Annual Rewiev Plant Biology, 71: 403-433.
40. Xu, C., Mou, B., 2015. Evaluation of lettuce genotypes for salinity tolerance. HortScience, 50(10): 1441-1446.
41. Zhao, S., Zhang, Q., Liu, M., Zhou, H., Ma, C., Wang, P., 2021. Regulation of plant responses to salt stress. International Journal of Molecular Sciences, 22(9): 4609.