Genome-Wide Identification, Comparative and Duplication Analysis of the F-box Gene Family in Chinese White Pear

Pear is a member of the Rosaceae family and is also the third-most important temperate fruit species. The genome of the domesticated Chinese white pear (Pyrus bretschneideri Rehd. cv. ‘Dangshansuli’) has been fully sequenced. F-box gene family plays crucial roles in regulating plant development, reproduction, cellular protein degradation and responses to biotic and abiotic stresses. However, comprehensive analysis of the F-box gene family in pear (Pyrus bretschneideri Rehd.) and other Rosaceae species has not been reported yet. Herein, we identified all the F-box genes in pear for the first time. And these genes were further divided into various subgroups based on specific domains and phylogenetic analysis. Intriguingly, we observed that the expansions of F-box gene family were resulted from different modes of gene duplication in pear update previous studies. Whole-genome duplication and dispersed duplication have a major contribution to F-box family expansion. Furthermore, the dynamic evolution for different modes of gene duplication was dissected, and the results showed that DNA-transposed or dispersed duplicates might have derived from more ancient duplication events. Interestingly, we observed that the expansions of F-box gene family were resulted from different modes of gene duplication in pear update previous studies. To further reveal the expression patterns of F-box family genes in pear, transcriptome sequencing data and digital expression profiles were investigated in several pear tissues including bud, pollen, fruit and calyx. Overall, these results will set rigid stage for elaborating the biological role of F-box genes in pear and other plants.