Genome-Wide Identification and Analysis of the Nuclear Factor Y Gene Family in the Woodland Strawberry Fragaria vesca

Abstract

Nuclear factor Ys (NF-Ys) are heterotrimeric transcription factors that specifically bind to CCAAT boxes present in numerous eukaryotic promoters. In plants, NF-Y proteins consist of the following three subunits: NF-YA, NF-YB, and NF-YC, each encoded by a gene family. Accumulating evidence underscores the crucial roles of NF-Y proteins in various plant development processes and stress responses, such as embryogenesis, flowering time control, drought tolerance, and heat tolerance. Despite this, a comprehensive genome-wide overview of the NF-Y gene family in strawberries is lacking. To bridge this gap, this study was conducted to identify and characterize the NF-Ys in Fragaria vesca. The investigation revealed the presence of six NF-YA, twelve NF-YB, and five NF-YC members in F. vesca. Furthermore, a comprehensive analysis of the FveNF-Ys was performed, including their phylogenetic relationships, gene structures, chromosomal locations, and conserved domains. MiRNA target site prediction found that there were 30 miRNA target sites in 12 (52.2%) FveNF-Y genes. Additionally, the expression profiles of different tissues and developmental stages demonstrated tissue-specific expression patterns among certain members of each NF-Y subfamily. This observation suggests that specific NF-Y subfamily members may play unique roles in different tissues or stages of development. Furthermore, the transient expression assay demonstrated that three selected FveNF-Ys were localized in the nucleus. Our study represents a pioneering effort in the systemic analyses of FveNF-Y genes and will be useful in understanding the functional characterization of NF-Y genes in Fragaria species.