Metabolome profiling to understand the defense response of sugar beet (Beta vulgaris) to Rhizoctonia solani AG 2-2 IIIB

• Defense response induced by Rhizoctonia solani AG 2-2 IIIB in sugar beet.
• 143 metabolites were differentially identified across all of the treatment conditions.
• Metabolites differed based on genotype and based on plant tissue type.
• Defensive metabolites were identified in susceptible and resistant interactions.

Rhizoctonia crown and root rot (RCRR), caused by Rhizoctonia solani Kühn AG 2-2 IIIB, is an important disease of sugar beet. While RCRR can be managed by agronomic practices, plant resistance remains the primary method for control. However, the molecular processes that mediate resistance to R. solani are largely unknown. The metabolic changes that occurred during susceptible and resistant R. solani interactions were compared and characterized using nontargeted metabolomic profiling. Metabolites from infected and healthy, root and leaf tissue, were taken at 0 and 7 dai and detected using reversed-phase UHPLC-MS and GC-MS. There was a clear distinction in the metabolome between tissue type and genotype, and in response to R. solani. 143 compounds were annotated and several metabolites associated with plant defense to fungi were identified in both germplasm.