Self-incompatibility (SI) is a complex mechanism that prevents plants from self-fertilizing to preserve and promote genetic variability. The angiosperm species have developed two different SI systems, the sporophytic (SSI) and the gametophytic (GSI) systems. SI is a significant impediment to steady fruit production in fruit tree species of the Rosaceae. In Rosaceae, GSI is genetically regulated via a single locus, named the ‘S-locus’, which includes a minimum of two polymorphic and relatively intercorrelated S genes: a pistil-expressed S-RNase gene and several pollen-expressed SFBB (S-locus F-Box Brothers) or SFB (S haplotype-specific F-box protein). This necessitates the interaction of S-RNases with the male determinants. Although genetic and molecular analyses of S genes have shown that mutations in both pistils and pollen-specific components induce self-compatibility in many species and cultivars, other genes or molecules outside the S-locus can co-participate in the male gamete rejection in GSI. However, we highlight and synthesize the most recent knowledge on different mechanisms of GSI in Rosaceae in this current review.

ALMT (aluminum-activated malate transporter) proteins play crucial roles in the transport of organic acids and have significant implications for plant stress responses and development. While extensively studied in some plants, the characteristics and functional divergence of the ALMT gene family have not yet been thoroughly explored in Prunus mume and some other Rosaceae species. In this study, we systematically analyzed the ALMT gene family across nine Rosaceae species to explore their evolutionary relationships, structural characteristics, and functional roles. A total of 138 ALMT genes were identified and categorized into four groups based on a phylogenetic analysis. The motif analysis confirmed the accuracy of the phylogenetic grouping. The collinearity analysis indicated that whole-genome duplication events were the primary drivers of ALMT gene expansion in these species. Furthermore, the cis-acting element analysis revealed diverse regulatory elements associated with environmental responses, including abscisic acid, light, and jasmonic acid. The gene expression correlation analysis showed that PmALMT1 is primarily associated with malic acid accumulation, whereas PmALMT8 is related to citric acid accumulation. Further transient expression in Nicotiana benthamiana validated the above conclusion. This comprehensive analysis provides valuable insights into the evolution, function, and regulation of the ALMT gene family in Rosaceae species.

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.