Karen-Beth Scholthof

Texas A & M University

Genetics and genomics of Brachypodium-virus interactions

Plant virus infections can be economically devastating to growers, causing annual crop yield losses of 15% or more. In comparison to the advances in understanding virus-host interactions in dicotyledonous plants, studies of virus-grass interactions have been hindered mainly due to the lack of a tractable monocot model system. The recent intensive and thoughtful development of Brachypodium distachyon (Brachypodium) as a model organism in the post-genome era of plant biology, has allowed us to investigate the complex molecular and genetic interactions that occur during virus infections of grasses. Using Panicum mosaic virus (PMV) and its satellites, we have identified mechanisms by which the Brachypodium host machinery subverts the replicative ability of virus infections in grasses. We have characterized genome-wide changes in Brachypodium transcriptome and defense signaling networks, splicing landscapes, as well as virulence determinants critical for PMV infection in grasses. In addition, comparative analyses of Brachypodium and Setaria viridis (a C4 grass) immune responses to eight monocot-infecting viruses made it possible to define conserved and unique defense mechanisms. Our studies underscore the utility of Brachypodium to advance fundamental studies of economically important viruses of grasses. I will discuss key outcomes, the research potential for the system in the coming years, and particular gaps in our understanding of virus-host resistance mechanisms.