Identification and Abiotic Stress Expression Profiling of Malic Enzyme-Associated Genes in Maize (Zea mays L.)

Malic enzyme (ME), a key enzyme involved in various metabolic pathways, catalyzes the oxidative decarboxylation of malate to generate pyruvate, CO₂, and NADPH. This enzyme plays essential roles in plant growth, development, and stress responses. In this study, 13 maize ME genes were identified by performing homologous sequence alignment using the sequences of the Arabidopsis ME gene family as references. Chromosomal localization analysis demonstrated that ME genes were not detected on chromosomes 9 and 10, whereas the remaining eight chromosomes exhibited an uneven distribution of these genes. Phylogenetic analysis indicated a high degree of conservation between maize ME genes and their orthologs in teosinte (Zea luxurians L.) throughout the evolutionary history of Poaceae crops. Furthermore, cis-acting element analysis of promoters demonstrated that members of the maize ME gene family harbor regulatory elements associated with stress responses, phytohormones signaling, and light responsiveness, which suggests their potential role in abiotic stress adaptation. Expression profiling under stress conditions revealed differential expression levels of maize ME genes, with ZmME13 emerging as a promising candidate gene for enhancing stress resistance. These results lay a solid foundation for further investigation into the biological functions of the maize ME gene family.