Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2020-2021).

The main objective of this proposal is to identify the molecular mechanisms of silicon (Si) absorption by plant species and to apply these findings towards improving plant resilience under harsh agricultural conditions. It rests on the well-established premise that Si accumulation protects plants against a variety of abiotic as well as biotic stresses. These benefits are more specifically observed in plants that express dedicated Si transport systems for Si uptake. One of these systems, the influx transporter 1 (Lsi1), a NIP-III from the aquaporin family, promotes Si influx across the exodermal and endodermal surfaces of root cells. The other system, the efflux transporter 2 (Lsi2), a putative anion transporter, promotes Si efflux across the same cells. Through recent structure-function studies in which the Si transport properties of Lsi1 and Lsi2 mutants were examined ,x000D
we have discovered that specific amino acid sequences and structural patterns confer differences among the various orthologs. By having identified the complete sequences of Lsi1 and Lsi2 and by using the heterologous expression system of Xenopus laevis to screen for such transporters, it will be possible to test hundreds of mutants or screen as many natural variants and to select the most promising ones for their ability to modulate Si accumulation in plants. Insights gained from such studies will be applied towards the production of climate-change i.e. drought and disease-resistant plants.