RESUMO
The transcription factor NF-YB (nuclear factor-YB) family is a subfamily of the nuclear factor Y (NF-Y), which plays an important role in regulating plant growth, development and participates in various stress responses. Although the NF-Y family has been studied in many species, it is still obscure in Eucalyptus grandis. In this study, 23 EgNF-YB genes in eucalyptus were identified and unevenly distributed on 11 chromosomes. Phylogenetic analysis showed the EgNF-YB genes were divided into two clades, LEC-1 type and non-LEC1 type. The evolution of distinct clades was relatively conservative, the gene structures were analogous, and the differences of genetic structures among clades were small. The expression profiles showed that the distinct EgNF-YB genes were highly expressed in diverse tissues, and EgNF-YB4/6/13/19/23 functioned in response to salinity, heat and cold stresses. Our study characterized the phylogenetic relationship, gene structures and expression patterns of EgNF-YB gene family and investigated their potential roles in abiotic stress responses, which provides solid foundations for further functional analysis of NF-YB genes in eucalyptus.