Genome-wide identification and expression analysis of NF-Y gene family in tobacco ( Nicotiana tabacum L.)

Nuclear factor Y (NF-Y) gene family is an important transcription factor composed of three subfamilies of NF-YA , NF-YB and NF-YC , which is involved in plant growth, development and stress response. In this study, 63 tobacco NF-Y genes ( NtNF-Ys ) were identified in Nicotiana tabacum L., including 17 NtNF-YAs , 30 NtNF-YBs and 16 NtNF-YCs . Phylogenetic analysis revealed ten pairs of orthologues from tomato and tobacco and 25 pairs of paralogues from tobacco. The gene structure of NtNF-YAs exhibited similarities, whereas the gene structure of NtNF-YBs and NtNF-YCs displayed significant differences. The NtNF-Ys of the same subfamily exhibited a consistent distribution of motifs and protein 3D structure. The protein interaction network revealed that NtNF-YC12 and NtNF-YC5 exhibited the highest connectivity. Many cis-acting elements related to light, stress and hormone response were found in the promoter of NtNF-Ys . Transcriptome analysis showed that more than half of the NtNF-Y genes were expressed in all tissues, and NtNF-YB9/B14/B15/B16/B17/B29 were specifically expressed in roots. A total of 15, 12, 5, and 6 NtNF-Y genes were found to respond to cold, drought, salt, and alkali stresses, respectively. The results of this study will lay a foundation for further study of NF-Y genes in tobacco and other Solanaceae plants.