Silicon (Si) has been studied and observed in a wide variety of plant species. Under the new definition of plant essential elements, Si is included, due to deficiency causing various abnormalities in plant growth and performance (Ma and Takahashi 2002; Epstein and Bloom 2003). The beneficial effects of Si are usually expressed more clearly in Si-accumulating plants under various abiotic and biotic stress conditions.
Silicon is effective in controlling various pests and diseases caused by both fungi and bacteria in different plant species (Bowen et al. 1992; Menzies et al. 1992; Datnoff et al. 2002). Silicon also alleviates effects on various abiotic stresses including salt stress, metal toxicity, drought stress, radiation damage, nutrient imbalance, high temperature, freezing (Takahashi 1966; Ma et al. 2001). These beneficial effects are mainly attributed to the high accumulation of silica on the tissue surface although other mechanisms have also been proposed.
To obtain plants resistant to multiple stresses, genetic modification of the root ability to take up Si has been proposed in addition to soil and foliar applications.
For more information regarding the role of Silicon please see the article Role of Silicon in Enhancing the Resistance of Plants to Biotic and Abiotic Stresses.