Genome-wide identification and analysis of the ZCN gene family in maize (Zea mays L.)

Background The development and growth of floral organs serve as a hallmark of the transition from vegetative to reproductive growth in plants. Phosphatidylethanolamine-binding proteins (PEBPs) play a critical regulatory role in this transition, additionally influencing the morphological structure of inflorescences. In maize ( Zea mays L.), PEBP proteins are encoded by the ZCN (Zea mays CENTRORADIALIS) gene family. However, the functional characteristics of this gene family remain poorly characterized. Results This study systematically identified and cloned a total of 25 ZCN gene family members. Phylogenetic analysis divided the ZCN gene family into four subclades: FT-like , TFL1-like , MFT-like , and PEBP-like . Comprehensive multi-dimensional analyses of gene structures, promoter cis-acting elements, tissue-specific and abiotic stress expression patterns of ZCN family members revealed their functional diversity, indicating that ZCN genes play crucial roles in maize growth and development. Subcellular localization results in maize protoplasts showed that ZCN7, ZCN8, ZCN17, ZCN18, ZCN21, ZCN24, and ZCN26 were exclusively localized in the nucleus. Additionally, nuclear localization signal sequences of ZCN17 , ZCN20 , and ZCN25 were identified as GRRYIR/GRRYR. Targeted editing of all ZCN members led to the generation of maize mutant lines with significantly increased tassel branch numbers and remarkably delayed flowering times under field conditions. Among these, ZCN3 , ZCN17 , ZCN20 , and ZCN25 were identified as key ZCN genes exhibiting significant regulatory effects on tassel branch number. Conclusions This study systematically identified 25 ZCN family members in the maize genome and comprehensively analyzed their gene structure, physicochemical properties, evolutionary relationships, expression patterns, and responses to abiotic stresses. Our results not only clarified the structural evolution and regulatory features of the ZCN gene family but also highlighted the functional roles of key genes. These findings have significantly advanced our understanding of the ZCN gene family in maize and provided genetic resources for maize molecular breeding.