Integrated analysis of transcriptomics and defense-related phytohormones to discover hub genes conferring maize Gibberella ear rot caused by Fusarium graminearum

Background Gibberella ear rot (GER) is one of the most devastating diseases in maize growing areas, which directly reduces grain yield and quality. To explore the molecular mechanisms underlying the host defense responses against pathogen infection, we analyzed the transcriptomics and defense-related phytohormones of ‘Nov-82’ (resistant inbred line) and ‘H10’ (susceptible inbred line) inoculated with Fusarium graminearum across six time points. Results By transcriptome analysis, 4,417 and 4,313 differentially expressed genes (DEGs) were identified in the Nov-82 and H10, respectively, and 647 genes were common DEGs among the two lines. These DEGs were remarkably enriched in the pathways related to the defense response pathways. In addition, defense-related phytohormones analysis showed that the jasmonates (JAs) and salicylates (SAs) were greatly induced after the pathogen infection, in which case the levels of JAs were more accumulation in H10 compared with Nov-82, whereas an opposite pattern for the SA between the both lines. Weighted gene co-expression network analysis (WGCNA) revealed five vital modules based on closely correlated between the DEGs and phytohormones. A total of 12 hub genes were obtained associated with plant defense processes through the integrated analysis of the DEGs and phytohormones, indicating that these genes might play a key role in GER disease. Conclusions Overall, this study reveals the transcriptional and phytohormonal responses under the pathogen infection, providing the theoretical basis for maize GER defense mechanisms, in addition to the identified hub genes that can be further investigated for enhancing GER resistance in maize.