Genome-wide analysis of the poplar NF-Y gene family and its expression in floral bud development of Populus tomentosa

Key message The NF-Y gene family was identified and characterized in Populus trichocarpa by genome-wide analysis. Expression of PtoNF-Y was analyzed during floral bud development in Populus tomentosa. Nuclear factor Y (NF-Y) is a transcription factor widely found in eukaryotes. It is composed of three subunits: NF-YA, NF-YB, and NF-YC. NF-Y has been identified as a key regulator of multiple pathways that control responses to developmental, biotic, and abiotic factors. Although the NF-Y gene has been reported in many plants, it has not been comprehensively analyzed in poplar. In this study, a total of 46 NF-Y gene family members in the P. trichocarpa genome were accessed using NF-Y amino acid sequences from Arabidopsis thaliana as a probe. In addition, bioinformatic characterization of NF-Y gene family members in P. trichocarpa, including gene structure, chromosome location, and phylogenetic relationships, was conducted. The results of chromosome distribution showed that the 46 PtNF-Y genes were distributed among 16 chromosomes of P. trichocarpa at varying frequencies. Gene-structure analysis showed that seven members have no introns. Phylogenetic analysis indicated that the NF-Y protein may have similar functions in Arabidopsis and P. trichocarpa. We used transcriptome data from different tissues to analyze the expression of the NF-Y genes in Populus tomentosa, and verified the results by qRT-PCR. The results indicated that some PtoNF-Y genes play significant roles in the floral bud development of P. tomentosa.