Background: Compared with annual herbaceous plants, woody perennials require a longer period of juvenile phase to flowering, and many traits can be only expressed in adulthood, which seriously makes the breeding efficiency of new varieties slower. For the study of poplar early flowering, the main focus is on the study Arabidopsis homologue gene CO/FT. Based on studies of Arabidopsis, rice and other plant species, some important research progress has been made on the regulation of flowering time by NF-Y subunits. However, little is known about the function of NF-Y regulating flowering in poplar.
Results: In the present study, we have identified PtNF-YB family members in poplar and focus on the function of the PtNF-YB1 regulate flowering timing using transgenic Arabidopsis and tomato. To understand this mechanisms, the expression levels of three known flowering genes (CO, FT and SOC1) were examined with RT-PCR in transgenic Arabidopsis. We used the Y2H and BiFC to assay the interactions between PtNF-YB1 and PtCO (PtCO1 and PtCO2) proteins. Finally, the potential molecular mechanism model in which PtNF-YB1 play a role in regulating flowering in poplar was discussed.
Conclusions: In this study, we have characterized the poplar NF-YB gene family and confirmed the function of the PtNF-YB1 regulate flowering timing. At the same time, we found that the function of PtNF-YB1 to improve early flowering can overcome species barriers. Therefore, PtNF-YB1 can be used as a potential candidate gene to improve early flowering by genetic transformation in poplar and other crops.
Keywords: Flowering time; Genome-wide analysis; Poplar; PtNF-YB1; Transgenic plant.