Probing the mechanisms of silicon-mediated pathogen resistance

Abstract

Silicon is the second most abundant mineral element in soil, it has important role in alleviating various environmental stresses and enhancing plant resistance against pathogen, but the exact mechanism by which Si mediates pathogen resistance remains unclear. One of the resistance mechanisms is related to silicon deposition in leaf that acts as a physical barrier to hinder pathogen penetration. But more evidence show that silicon can induce defense responses that are functionally similar to systemic acquired resistance, Si-treated plants can significantly increase antioxidant enzyme activities and the production of antifungal compounds such as phenolic metabolism product, phytoalexins and pathogenesis-related proteins etc. Molecular and biochemical detections show that Si can activate the expression of defense-related genes and may play important role in the transduction of plant stress signal such as salicylic acid, jasmonic acid and ethylene.

Silicon-mediated mitigation of wounding stress acts by up-regulating the rice antioxidant system

“…Si-transporter genes were found to be exponentially regulated within a short time span, ranging from a few minutes to several hours, leading to the accumulation of Si inside plant tissues (Ma and Yamaji 2008). These Si deposits protect rice cells and tissues from multiple abiotic and biotic stresses, including physical injury or herbivory (Cai et al 2009;Bockhaven et al 2012).…”

The role of silicon (Si) in increasing plant resistance against fungal diseases

“…Defense-related enzymes have an important role in regulating the production and accumulation of lignin, fl avonoids, and phytoalexins (Cai et al, 2009). Rodrigues et al (2005) reported the strong induction of pathogenesis-related protein transcripts following infection by Magnaporthe grisea, which corresponded to an increase in the concentration of lignin in rice plants.…”

“…When infected with necrotizing pathogens, many plants developed an enhanced resistance against further pathogen attack, which is referred to as systemic acquired resistance (SAR) (Conrath, 2006). The two mechanisms involved in increasing the activity of enzymes and antifungal compounds due to silicon application on plants could induce defense response similar to SAR (Cai et al, 2009). Moreover, there might be other biochemical and physiological mechanisms involved in the silicon-mediated resistance of plants to diseases.…”

“…However, the biochemical pathways by which the phenolic metabolism might mediate silicon-enhanced plant resistance to fungi remains unclear (Fauteux et al, 2005;Datnoff et al, 2007;Van Bockhaven et al, 2013). Silicon application induces the production of antifungal compounds after pathogen penetration of the epidermal cells (Cai et al, 2009).…”

The effect of foliar fertilization with marine calcite in sugar beet

“…Silicon plays a very important role in the reduction of the plants vulnerability to biotic and abiotic environmental stress (Fauteux et al 2005, Mitani and Ma 2005, Ma and Yamaji 2006, Liang et al 2006, Gunes et al 2007, Sacała 2009). This component increases the plants' resistance to pathogens and pests (Samuels et al 1993, Fawe et al 1998, Raven 2003, Henriet et al 2006, Cai et al 2009). One of the most important beneficial effects of silicon on plant growth is related to increased resistance under water stress conditions (Ma et al 2004, Sacała 2009).…”