Transcriptomic analysis of Fusarium graminearum disease response in near-isogenic hexaploid wheat lines differeing for the presence of a resistance QTL on chromosome 2DL

To mine the molecular response associated with the wheat 2DL FHB resistance QTL and to identify candidate genes implicated in such esistance, a comprehensive transcriptomic analysis of the early response to F. graminearum infection in spikelet and rachis was performermed with the RNA-Seq and miRNA-Seq techniques. The analyses were conducted on two near isogenic lines differing for the presence of the 2DL QTL. The response to fungal infection in terms of mRNAs accumulation trend was similar in both NILs, even if at higher intensity in the susceptible NIL, and involved inhibition of primary metabolism and activation of secondary metabolism, amino acid metabolism, cell all reinforcement and remodelling, scavenging of ROS, hormone metabolism and signalling, detoxification and induction of several genes encoding transcription factors and proteins implicated in pathogens resistance response. To search for candidate genes with expression profiles associated with the 2DL QTL resistance led to the discovery of two different strategies associated with sugar signalling in the two NILs. Two genes associated with FHB suscaptibility were discovered. Altered expression was also observed for fungal non-coding RNAs which putative targets were represented by the WIR1A gene, involved in resistance response, and a gene encoding for a jacalin-related lectin protein, which partecipate in biotic and abiotic stress response. The data support the presence of a cross-talk between the plant and the fungus.