Zm-Prx5 confers resistance against stalk rot caused by Fusarium graminearum infection in maize

Maize stalk rot caused by Fusarium graminearum infection is one of the most devastating diseases affecting crops worldwide, causing considerable losses in maize production and quality. Reactive oxygen species (ROS) play fundamental roles in plant immune responses; however, whether and how ROS participate in maize resistance to Fusarium graminearum-induced stalk rot have not been fully elucidated to date. In this study, employing a quantitative proteomics approach, we identified differentially accumulated proteins (DAPs) in maize following Fusarium graminearum infection and reported that one DAP, peroxiredoxin 5 (Zm-Prx5), as an antioxidant enzyme, functions in maize resistance to stalk rot caused by the pathogen. Zm-Prx5, localized in the cytosol, was observed to accumulate after Fusarium graminearum infection. The uniform Mu mutant of Zm-Prx5 exhibited increased susceptibility to Fusarium graminearum, while Zm-Prx5-overexpressing transgenic maize lines exhibited enhanced resistance to infection. Additionally, Fusarium graminearum infection substantially induced H2O2 accumulation in infected maize stems, while this induction was significantly upregulated in the Zm-Prx5 mutant but was downregulated in Zm-Prx5-overexpressing lines compared with their wild-type counterparts. Furthermore, transcriptome analysis demonstrated that numerous genes associated with ROS metabolism, stress response, biosynthesis of secondary metabolites and phytohormone signalling were differentially expressed in the Zm-Prx5 mutant. Taken together, the results of our study demonstrate that Zm-Prx5 confers maize resistance to F. graminearum infection through changes in H2O2 accumulation.