Molecular characterization and evolutionary relationships of DOFs in four cherry species and functional analysis in sweet cherry.

The DOF (DNA binding with one finger) has multiple functions in plants. However, it has received little attention in the research field of cherries. In this study, the evolutionary relationship and molecular characterization of DOF in four cherry species were analyzed, revealing its expression pattern in sweet cherry. There are 23 members in Prunus avium cv. 'Tieton', 88 in Prunus cerasus, 53 in Cerasus × yedoensis, and 27 in Cerasus serrulata. Most of these genes are intron-less or non-intron, with a conserved C2-C2 domain. Due to heterozygosity and chromosomal ploidy, whole-genome duplication (WGD) events occur to varying degrees, and DOF genes are contracted during evolution. Furthermore, these genes are affected by purifying selection pressure. Under low-temperature treatment, the expression of PavDOF2 and PavDOF18 were significantly up-regulated, while that of PavDOF16 is significantly down-regulated. The expression of PavDOF9, PavDOF12, PavDOF14, PavDOF16, PavDOF17, PavDOF18, and PavDOF19 exhibits an increasing trend during flower development and varies during sweet cherry fruit development. PavDOF1, PavDOF8, PavDOF9, and PavDOF15 are localized in the nucleus but is not transcriptionally active. The findings systemically demonstrate the molecular characteristics of DOF in different cherry varieties, providing a basis for further research on the functions of these genes.