Professor Nanjing Agricultural University Nanjing, Jiangsu, China (People's Republic)
Body of Abstract: Gibberella root rot (GRR) caused by Fusarium graminearum is one of the devastating soil-borne diseases of maize. However, the mechanisms underlying GRR resistance remain largely unexplored. Furthermore, despite that rhizosphere microbiota has been known to play important roles in plant-pathogen interactions, it is unclear whether rhizosphere microbiota impacts GRR resistance. A joint metabolomics and microbiome analysis was deployed to characterize the essential metabolites and beneficial bacterial microbes associated with GRR resistance using two inbred lines with contrast GRR phenotypes. Various flavonoid compounds were enriched and their biosynthesis gene expression levels were higher in resistant line compared to susceptible line. Sakuranetin, one of the intermediate flavonoid metabolites, showed inhibitory effect on F. graminearum growth in vitro. Rhizosphere microbiome analysis showed that while two lines displayed distinct pattern of bacterial community structure, higher network node connections, stronger positive correlation connections and shorter average paths were found in resistant line compared to susceptible line. Moreover, Flavobacterium is greatly enriched in resistant line than susceptible line and the most abundant OTU of Flavobacterium is Flavobacterium anhuiense. The direct connection between flavonoid compounds and rhizosphere microbiota associated with GRR resistance is being investigated using genetic materials for flavonoid biosynthesis.