Silicon has been shown to enhance the resistance of plants to fungal and bacterial pathogens, however the underlying mechanisms have not been studied in detail in most plants.
Whan et al. compare cellular and biochemical modifications in root tissue of two cotton cultivars grown in media amended with soluble potassium silicate, and inoculated with a vascular wilt pathogen, Fusarium oxysporum f. sp. vasinfectum. Cellular defences, including deposition of electron dense material and accumulation of phenolic compounds, were more rapidly induced and more intense after Si treatment in a cultivar with greater inherent resistance to the pathogen.
Jennifer A. Whan, Elizabeth K. Dann, Elizabeth A. B. Aitken, 2016, 'Effects of silicon treatment and inoculation withFusarium oxysporumf. sp.vasinfectumon cellular defences in root tissues of two cotton cultivars', Annals of Botany, vol. 118, no. 2, pp. 219-226 http://dx.doi.org/10.1093/aob/mcw095