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, cis-acting regulatory elements, and expression profiles were comprehensively analyzed. Twenty PFK 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 (Oryza sativa), but none with Arabidopsis thaliana. Promoter analysis indicated the presence of cis-regulatory elements associated with growth, development, and stress responses. Transcriptome data and qRT-PCR analysis demonstrated differential expression of ZmPFK genes across tissues and under various stress treatments. Several ZmPFK genes responded to abiotic stresses (salt, drought, heat, and cold) as well as biotic stresses caused by Cochliobolus heterostrophus, Exserohilum turcicum, and Fusarium graminearum, suggesting a potential role for the PFK family in stress adaptation. Moreover, the recombinant plasmid ZmPFK10-pET32a was introduced into Escherichia coli 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.