Study of sugarcane metabolism modulation by the plant pathogenic fungus Sporisorium scitamineum

Abstract

The sugarcane is currently listed as one of the main sources of biomass energy. The carbon partioning obtained during photosynthesis is essential for generating high concentrations of sucrose in the plant stem. This distribution can be affected by several factors inherent or not to the plant, such as age and the presence of pathogens, respectively. The pathogenic fungus Sporisorium scitamineum establishes a biotrophic relationship with sugarcane, causing the disease known as "smut", characterized by the formation of a structure like a whip. Data from transcripts sequencing (RNAseq) of the interaction of sugarcane and S. scitamineum showed that the presence of the fungus causes changes in expression of genes related to primary and secondary metabolism of the plant, including synthesis from sucrose, cellulose, starch , xylose, lignin and phytohormones. However, changes in mRNA levels do not always correlate directly to changes in the same degree in the respective proteins and metabolites and hence in the biochemical phenotype of the plant. Thus, the objective of this project is to investigate how the plant pathogenic fungus S. scitamineum modulates the sugarcane metabolism and influences the carbon portioning between intermediates of the major plant biochemical pathways during disease development. Therefore, profiles of metabolites and proteins will be obtained from a biochemically susceptible variety of sugarcane (RB925345) at different times of disease development. From the generated data genes involved in the pathways regulated by the fungus presence will be selected and their expression monitored during disease development using the qRT-PCR technique. The results are expected to give an overview of the metabolic changes caused by the presence of a biotrophic pathogen in sugarcane and provide new information on the mechanisms involved in plant-pathogen interaction.