Cassava (Manihot esculenta) is an important food security crop. Although cassava is prized as a highly productive crop even when grown without irrigation or fertilizer, it suffers from several microbial pathogens. In this talk, I will cover three of the most important diseases of cassava: Cassava mosaic disease (CMD) caused by species of DNA geminiviruses, Cassava Brown Streak Disease (CBSD) caused by an RNA viral pathogen, and Cassava Bacterial Blight (CBB), caused by Xanthomonas.

In the first story, I will describe cloning of the CMD2 resistance gene, a novel type of resistance that we predict will be broadly effective against geminiviruses. In the second story, I will cover our work on susceptibility (S) genes. S genes are encoded in the host genome and are required by the pathogen to complete its lifecycle. I will describe our work on exploring the biology of these unique pathosystems.

Further, I will share recent data using various genome and epigenome editing tools to prevent the pathogens from accessing their cognate S genes and how, generally, these approaches can be used to promote host resistance.