Identification and Functional Analysis of Transcription Factor NF-Y Family during Flower Bud Dormancy in Prunus mume

NF-Y transcription factor consists of three subsets, A, B, and C, which play various roles during biological processes in plants, particularly in growth and development, stress response, and microorganism interactions. The current study was exhaustively conducted on the NF-Y gene family in Prunus mume (Japanese apricot). We identified 27 PmNF-Y genes that were distributed on eight chromosomes of the Japanese apricot genome, and which were divided into three subgroups according to their phylogenetic relationship. Protein replication analysis showed that the Ka/Ks ratio of one pair of tandem repeats and two pairs of segmental repeats was less than 1. Cis-acting elements upstream of PmNF-Y genes were divided into four distinct categories: light response, growth metabolism, stress, and hormones, among which the numbers of hormone and light-responsive cis-acting elements were higher. RNA-seq analysis revealed that most of the genes were expressed with slight variation in various tissues. Interestingly, some genes were expressed differently during dormancy. During dormancy with exogenous hormones and low temperature, the qRT-PCR results showed that these differentially expressed genes had specific expression responses under GA4, ABA, MeJA, and low-temperature treatments. Therefore, these findings could provide a novel theoretical foundation for future research into the function and molecular regulation mechanism of the NF-Y gene family in the Prunus species.