Genome-wide identification and characterization of xyloglucan endotransglucosylase/hydrolase gene family in maize (Zea mays L.) and the function of ZmXTH30 in response to drought stress

The xyloglucan endotransglucosylase/hydrolase (XET/XEH, also known as XTH) family is a crucial multigene family in plants, playing a key role in cell wall reconstruction and stress tolerance. While the ZmXTH genes in maize (Zea mays L.) have not been thoroughly studied, this research aimed to identify and characterize them on a genome-wide scale. A total of 31 ZmXTH genes were identified, with phylogenetic analyses indicating their closest relation to rice (Oryza sativa L.) OsXTH family members. Evolutionary analysis revealed genetic variation in ZmXTH genes during the shift from dicotyledons to monocotyledons, with evidence of purifying selection throughout their evolution. Notably, ZmXTH14, ZmXTH26, and ZmXTH30 showed significant upregulation under abiotic stress, suggesting their importance in stress responses. Furthermore, transgenic expression of ZmXTH30 in Arabidopsis (Arabidopsis thaliana) improved seedling growth under drought stress by reducing reactive oxygen species and enhancing antioxidant enzyme activity, underscoring the role of ZmXTH30 in plant drought tolerance. These findings provide valuable insights for further exploring the functions and applications of ZmXTH genes in maize.