Highlights and Prospects for Using Silicon in the Future

Abstract

As a result of silicon research from the 1980s until today, a number of facts can be stated about the role this element plays in plant disease suppression. These include the following: for any plant disease, a minimum silicon concentration is needed to suppress that disease; once that level has been obtained, plant disease suppression increases proportionally as the silicon concentration (insoluble or soluble) increases in plant tissues; the silicon supply to a plant must be continuous or the disease-suppressing effects will be reduced or non-existent; silicon can influence many components of host resistance; silicon may augment susceptible and partial resistance almost at the same level as complete genetic resistance; only when applying silicon to the roots will this element mediate plant defenses at both the physiological and molecular level; and silicon may suppress plant diseases as effectively as fungicides. In spite of the recent advances linking silicon to host resistance via the -“omics”, namely, genomics, proteomics and metabolomics, the exact mechanism(s) by which this element modulates plant physiology through an increase in host resistance requires further investigation. Silicon undoubtedly deserves more attention by scientists and agriculturalists, but its recognition is limited by current perspectives on whether agricultural soils are truly low in this element, whether the plant in question will accumulate silicon and whether silicon is to be viewed as a fertilizer, biostimulant or plant protectant. Nevertheless, as researchers and growers become more aware of silicon and its potential, it is likely that this often overlooked, quasi-essential element will be recognized as a viable means of enhancing plant health and performance.