Comparative proteomic analysis reveals insights into the dynamic responses of maize (Zea mays L.) to Setosphaeria turcica infection.

Maize (Zea mays L.) production is severely affected by northern corn leaf blight (NCLB), which is a destructive foliar disease caused by Setosphaeria turcica. In recent years, studies on the interaction between maize and S. turcica have been focused at the transcription level, with no research yet at the protein level. Here, we applied tandem mass tag labelling and liquid chromatography-tandem mass spectrometry to investigate the proteomes of maize leaves at 24 h and 72 h post-inoculation (hpi) with S. turcica. In total, 4740 proteins encoded by 4711 genes were quantified in this study. Clustering analyses provided an understanding of the dynamic reprogramming of leaves proteomes by revealing the functions of different proteins during S. turcica infection. Screening and classification of differentially expressed proteins (DEPs) revealed that numerous defense-related proteins, including defense marker proteins and proteins related to the phenylpropanoid lignin biosynthesis, benzoxazine biosynthesis and the jasmonic acid signalling pathway, participated in the defense responses of maize to S. turcica infection. Furthermore, the earlier induction of GST family proteins contributed to the resistance to S. turcica. In addition, the protein-protein interaction network of DEPs suggests that some defense-related proteins, for example, ZmGEB1, a hub node, play key roles in defense responses against S. turcica infection. Our study findings provide insight into the complex responses triggered by S. turcica at the protein level and lay the foundation for studying the interaction process between maize and S. turcica infection.