Genome-wide identification and expression analysis of the ZmPFK gene family under biotic and abiotic stresses in maize

Phosphofructokinase (PFK) is a key regulatory enzyme in the glycolytic pathway, functioning as the rate-limiting enzyme that controls the pace of intracellular glucose metabolism. In parallel, hexokinase not only serves as a sugar sensor initiating downstream sugar signaling, but also integrates various external cues, thereby activating other signaling pathways and contributing to the regulation of plant responses to environmental stimuli. A systematic investigation of the gene structure, evolutionary relationships, and expression patterns of PFK family members in maize is crucial for advancing our understanding of their biological functions. In this study, a genome-wide identification of PFK family members was conducted in the maize inbred line B73 using bioinformatics approaches. The physicochemical properties, phylogenetic relationships, gene structures, <italic>cis</italic>-acting regulatory elements, and expression profiles were comprehensively analyzed. Twenty <italic>PFK</italic> genes were identified in B73, categorized into ATP-dependent phosphofructokinases (PFKs) and pyrophosphate-dependent phosphotransferases (PFPs), and were found to be unevenly distributed across different chromosomes. Collinearity analysis revealed multiple homologous genes between maize and rice (<italic>Oryza sativa</italic>), but none with <italic>Arabidopsis thaliana</italic>. Promoter analysis indicated the presence of <italic>cis</italic>-regulatory elements associated with growth, development, and stress responses. Transcriptome data and qRT-PCR analysis demonstrated differential expression of <italic>ZmPFK</italic> genes across tissues and under various stress treatments. Several <italic>ZmPFK </italic>genes responded to abiotic stresses (salt, drought, heat, and cold) as well as biotic stresses caused by <italic>Cochliobolus heterostrophus</italic>, <italic>Exserohilum turcicum</italic>, and <italic>Fusarium graminearum</italic>, suggesting a potential role for the PFK family in stress adaptation. Moreover, the recombinant plasmid <italic>ZmPFK10</italic>-pET32a was introduced into <italic>Escherichia coli</italic> BL21, and the resulting strain exhibited enhanced growth under 700 mmol L^-1 NaCl and 45℃, compared to the control. Protein interaction network prediction and enrichment analysis further revealed that three core proteins interacting with ZmPFK are involved in glycolysis. These findings provide a theoretical foundation for future functional characterization of PFK family members in maize.