Maize (Zea mays L.) is one of the most important food crops. Salt stress can hinder crop growth and development, but the molecular mechanisms underlying maize’s response to salt tolerance remain unclear. In this study, we conducted comparative transcriptome, metabolome, and physiological analyses of a salt-tolerant maize inbred line (J1285) subjected to different NaCl concentrations during the seedling stage. The results demonstrated that, with increasing salt concentration, seedling growth parameters and antioxidant enzyme activities (SOD, POD, CAT) exhibited initially increases before subsequently decreasing, peaking at 50–150 mmol/L. Transcriptome data analysis revealed that the experimental groups subjected to 50, 100, 150, and 200 mmol/L treatments had 375, 1043, 2504, and 2328 differentially expressed genes (DEGs) compared to the control group, respectively. Additionally, through GO and KEGG analysis, we found that the DEGs were primarily enriched in the MAPK signaling pathway and plant hormone signal transduction, especially the abscisic acid (ABA) signaling pathway, both of which play instrumental roles in orchestrating the maize response to salt-induced stress. Transcription factors involved in the salt stress response, including WRKY, TIFY, bZIP, and bHLH, were identified. Metabolomic data analysis revealed that the experimental groups subjected to 50, 100, 150 and 200 mmol/L treatments had 44, 335, 278, and 550 differentially expressed metabolites (DEMs) compared to the control group, respectively. The DEMs were mainly enriched in metabolic pathways and the biosynthesis of secondary metabolites. Transcriptomics and metabolomics combined analysis were performed on J1285 seedling leaves, and it was found that the co-enrichment pathways included starch and sucrose metabolism, linoleic acid metabolism, α-linolenic acid metabolism, phenylpropanoid biosynthesis pathway, etc. Collectively, these results will aid in identifying resistance genes and elucidating the molecular mechanisms underlying salt tolerance for maize.

In this study, the gene ZmPR5, associated with resistance to ear rot, was identified through transcriptome data analysis of the maize inbred line J1259. The gene was subsequently cloned and its function was investigated. The ZmPR5 gene comprises an open reading frame of 525 base pairs, encoding a protein of 175 amino acids. ZmPR5 was overexpressed in Arabidopsis and the ZmPR5EMS mutant in maize, and they were subjected to q-PCR and measurements of antioxidant enzyme activities (POD, SOD, CAT, MDA), electrical conductivity, and chlorophyll content. The results indicate that the expression of ZmPR5 is up-regulated upon infection by Fusarium verticillioides, with significant differences observed in the activities of POD, SOD, CAT, MDA, electrical conductivity, and chlorophyll content. The study found that ZmPR5 is localized in the nucleus and interacts with Zm00001d020492 (WRKY53) and Zm00001d042140 (glucA). Trypan blue staining revealed that the stained area in the ZmPR5EMS mutant of maize was significantly larger than that in B73. The expression of ZmPR5 is closely associated with resistance to maize ear rot.