The DOF (DNA-binding with one finger) transcription factors are exclusive to plants and play crucial roles in plant growth, development, and environmental adaptation. Although extensive research has been conducted on the
Dof gene family in
Arabidopsis,
maize, and
Solanum, investigations concerning the role of this gene family in
Liriodendron remain unreported, leaving its biological function largely unknown. In this study, we performed a comprehensive genome-wide identification of the
Dof gene family based on the
Liriodendron genome, resulting in the discovery of a total of 17
LcDof gene members. Based on the results of phylogenetic analysis, the 17 LcDof proteins were classified into eight subfamilies. The motif analysis revealed the diverse nature of motifs within the D1 subfamily, which includes a distinct type of Dof transcription factor known as
CDF (Cycling Dof Factor). We further characterized the chromosomal distribution, gene structure, conserved protein motifs, and cis-elements in the promoter regions. Additionally, utilizing transcriptome data from
Liriodendron hybrids and conducting RT-qPCR experiments, we investigated the expression patterns of
LhDofs under various abiotic stresses such as drought, cold, and heat stress. Notably, we found that several
LhDofs, particularly
LhDof4 and
LhDof6, were significantly upregulated in response to abiotic stress. Furthermore, we cloned
LhDof4 and
LhDof6 genes and found that its encoding protein was mainly located in the nucleus by transient transformation in
Liriodendron hybrids protoplast. Subsequently, we used
LhDof6-overexpressing
Liriodendron hybrid seedlings. We found that overexpression of
LhDof6 enhanced the cold tolerance of the plants, increasing their survival rate at −20 °C. This result was further validated by changes in physiological indicators.
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