Silicon Transporters and the Benefits of Silicon in Plants.

Although silicon (Si) is not considered as an essential element for plant growth, its uptake is beneficial in alleviating abiotic and biotic stresses. These positive effects are not always manifest since accumulation differs among plant species. This differential accumulation was poorly understood or explained until the discovery of specific genes involved in Si uptake. These genes were first described in rice with homologs reported in maize and barley. With the advent of high throughput sequencing and easier access to genomic data, it is now possible to determine with precision the potential of a plant to accumulate Si, and therefore benefit from its absorption, on the basis of its genetic predisposition. For example, wheat is another plant species known to accumulate fairly large concentrations of Si and to respond well to Si treatment. From this premise, we sought to identify and characterize the presence of Si-transport genes in wheat, and to determine their functionality and localization. Our results have allowed the identification and the cloning of a putative Si-transport gene presenting high homology (>80 %) with the Si-influx protein in rice known as Lsi1. Horsetail is another plant species possibly known as the greatest absorber of Si that offers great potential to unveil Si transporters. Through the sequencing of the horsetail root transcriptome, we have found a new family of Si transporters with unique properties. The discovery of these transporters provides a unique opportunity to understand the uptake of Si and possibly devise new strategies to control plant diseases.