Exploring the molecular cross-talk of the biotrophic pathogen Sporisorium scitamineum and its host sugarcane: the use of Arabidopsis as a model system

Abstract

Among the relevant issues impacting sugarcane agricultural practices are fungal diseases that constitute a worldwide threat to the cultivation. Smut is one of these diseases maintained in crop fields since its identification and that re-emerges in the international scenario mostly due to climate changes and modern green harvesting practices. Sporisorium scitamineum is the causal agent of sugarcane smut. The disease is characterized by the development of a whip-like structure from the shoot apical meristem (SAM) of sugarcane, which is associated with fungal sporogenesis. Infected SAM produces the whip instead of flowers or any floral organs. The most effective way to control smut is the selection of resistant varieties. However, durable resistance is always at risk as the pathogen displays genomic variability and, thereby, potential to adapt to a changing environment and to overcome resistance. Hence, a deep understanding of the pathogen virulence and sugarcane biology is essential to control this disease. Smut has been the focus of our studies aiming at deciphering the molecular cross-talking between host and pathogen. Here, we propose to study the biological function of selected effector candidates of S. scitamineum that manipulate sugarcane metabolism to allow fungal infection, colonization and sporogenesis. I hypothesize that some of the fungal effectors interfere with the normal transition of SAM from vegetative stage to reproductive stage triggering whip emergence since shortly after inoculation. We intend to use the well-established model system for floral organ development of Arabidopsis thaliana to provide insights into the gene regulatory network underlying events that may precede whip development in sugarcane. (AU)