Mechanistic roles of DNA polymerase δ subunit 1 in resistance to DNA geminiviruses.

01/09/2023 to 31/08/2026

Geminiviruses are DNA viruses that infect many important crop species including cassava, cotton, okra, soybean, maize, tomato and other Solanaceae1. To complete their life cycles, geminiviruses use host DNA polymerases to replicate their own genomes. DNA polymerase δ, of which DNA polymerase δ subunit 1 (POLD1) is the catalytic subunit, is essential for geminiviral replication2. We recently identified specific amino acid changes within the cassava POLD1 protein that confer dominant resistance to cassava geminiviral pathogens3. Our exploration of publicly available genomic data suggests that similar resistance alleles may exist in tomato, cotton, and soybean (unpublished). How the specific amino acid changes within POLD1 confer resistance remains unclear. The research proposed here will reveal the molecular mechanisms that underlie POLD1-mediated resistance and test the hypothesis that this resistance mechanism can be functional in diverse plant species. Our team will also engage in activities to increase public awareness and appreciation for science and will provide training to students with an emphasis on increasing STEM opportunities for underrepresented minorities.