The YABBY transcription factor family plays a critical role in the development of lateral organs and the establishment of polarity in plants. However, its evolutionary dynamics and regulatory functions in response to abiotic stress in maize (Zea mays) remain unclear. In this study, we conducted a genome-wide analysis of the maize YABBY gene family, employing phylogenetic analysis, transcriptomics, co-expression networks, and molecular experiments. A total of 12 ZmYABBY genes were identified from 26 maize inbred lines and classified into five conserved subfamilies. Evolutionary analysis indicated that the family is structurally stable, predominantly shaped by purifying selection, with limited lineage-specific variation among hybrid populations, highlighting its high evolutionary conservation. In contrast, transcriptomic analysis revealed functional diversification: ZmYABBY genes were preferentially expressed in floral organs and exhibited distinct response patterns under drought and heat stress. Notably, co-expression network analysis identified ZmYABBY8 as a hub gene that was significantly induced under drought stress, as validated by RT-qPCR. Furthermore, its promoter region was found to be enriched with conserved stress-responsive cis-elements, including ABRE and DRE. Subcellular localization further confirmed that ZmYABBY8 is localized to the nucleus. In summary, the maize YABBY gene family is evolutionarily conserved yet functionally diversified, with ZmYABBY8 acting as a potential hub linking development and stress responses, making it a promising candidate for improving stress tolerance in maize.
Keywords: ZmYABBY8; drought stress; expression analysis; genome-wide identification; heat stress; maize.