Comparative analysis of the transciptional profile of the sugarcane smut disease pathogen during the interaction with resistant and susceptible genotypes

Abstract

The sugarcane smut disease is caused by Sporisorium scitamineum, a dimorphic and biotrophic fungus, host-dependent to its sexual reproduction and teliospores formation. The Genomics Group has been extensively studying the sugarcane-smut interaction for the past few years, considering various aspects of the interaction, including pathogen attack mechanisms and plant defense responses. Pathogens can modulate plant physiology using molecules known as effectors. Previously we predicted about 70 candidate effectors among 305 proteins of the S. scitamineum secretome. Among these, orthologs functionally characterized in Ustilago maydis (Maize smut) were identified. Regarding plant response, we demonstrated that the first sugarcane defense response to the pathogen attack is the oxidative burst. Only resistant genotypes induced ROS during colonization and associated with fungal development stages (germination, appressorium formation, and colonization of plant tissues). The present project aims to better understand the mechanisms of fungal attack by analyzing the transcriptional profile (RNA-Seq) of the S. scitamineum pathogen, in two sugarcane varieties with different levels of resistance to smut in the early moments of interaction (48 hours after inoculation). Emphasis will be given to comparing the secretome profile and that of effectors candidates genes. (AU)