Genome-Wide Identification and Expression Analysis of the NF-Y Transcription Factor Family in Prunus armeniaca

The nuclear factor Y (NF-Y) gene family plays important roles in regulating many of the biological processes of plants, including oil accumulation. The apricot (Prunus armeniaca) is one of the most commercially traded plants, and apricot kernel oil has a high nutritional value owing to its richness in fatty acids and bioactive compounds. However, the systematic characterization of the PaNF-Y family in the apricot and the underlying regulatory mechanisms involved in oil biosynthesis remain unclear. In this study, a total of 28 PaNF-Y members from the apricot genome were identified and divided into three subfamilies (6 PaNF-YAs, 15 PaNF-YBs, and 7 PaNF-YCs) based on phylogenetic analysis results. The types and distributions of the gene structures and conserved motifs were similar in the clustered PaNF-Ys of the same subfamily. Gene duplication analysis results revealed that segmental duplication events were important for the expansion of the PaNF-Y family. Importantly, transcriptome data analysis results showed that most genes of the PaNF-YA subfamily and PaNF-YB4 of the PaNF-YB subfamily were specifically expressed in the apricot kernel. Furthermore, highly positive correlations were observed between apricot oil content and the transcript levels of PaNF-YA2, PaNF-YA6, and PaNF-YB4. In conclusion, our results provide insights into the molecular mechanisms of the key PaNF-Y genes regulating apricot oil biosynthesis.