Resumen
The highly conserved actin depolymerizing factor (ADF) plays an important role in plant growth, development and responses to biotic and abiotic stresses. A total of 72 ADF genes in Arabidopsis, wheat, rice and sorghum can be divided into four groups. The multicollinearity analysis revealed that the maize ADF gene family exhibited more collinearity events with closely related gramineous plants. Fifteen ADF genes in maize were screened from the latest database, and bioinformatics analysis showed that these ADF genes were distributed across seven chromosomes in maize. The gene structure of the ADF gene family in maize exhibits significant conservation and cluster consistency. The promoter region contains rich regulatory elements that are involved in various regulations related to growth, development and adverse stresses. The drought-tolerant ZmADF5 gene in maize was further studied, and it was found that the allelic variations in ZmADF5 were mainly concentrated in its promoter region. A superior haplotype, with drought tolerance, was identified by candidate-gene association analysis of 115 inbred lines. By comparing the phenotypes of anthesis silking interval, grain yield and ear height, it was found that Hap2 performed better than Hap1 under drought stress. This study provides a theoretical reference for understanding the function of the ADF gene family and proposes further investigation into the role of ZmADF5 in abiotic-stress tolerance.