Objective In order to analyze the role of the transcription factor ZF-HD in the growth and development in Eucalyptus and to further understand its function, ZF-HD gene family in eucalyptus.

Method  In this study, bioinformatics was used to identify members of the E. grandis ZF-HD gene family, and their chromosomal location, physical and chemical properties, gene structure, protein conserved domains and expression patterns were analyzed.

Result A total of 10 ZF-HD gene members were identified in E. grandis, which encoded 78-343 amino acids. Meanwhile, almost all genes were basic proteins which mainly located in the nucleus. Moreover, motif1 is very conserved in the ZF-HD family, and their cis-acting promoter elements mainly included hormone response, growth and development, and stress response elements. Furthermore, the expression analysis of ZF-HD gene in various tissues, adventitious roots and buds inducing process was analyzed. The results showed that most of the family members were differentially expressed in various tissues, which mainly acted in the downward direction of stem apex, Meanwhile, the expression levels of ZF-HD family members altered significantly during adventitious root and bud induction. EgrZHD2 expressed in higher level at the stem apex and decreased significantly with gradually increased secondary growth. And the further subcellular localization analysis showed EgrZHD2 localized in cell nucleus, which was consistent with predicted results.

Conclusion The ZF-HD gene family members of Eucalyptus grandis play an important regulatory role in the development of adventitious roots and adventitious buds. EgrZHD2 acts as an important transcription factor in the biological processes of primary growth and adventitious root induction in Eucalyptus.