RESUMO
BACKGROUND: ACO (1-aminocyclopropane-1-carboxylic acid) serves as a pivotal enzyme within the plant ethylene synthesis pathway, exerting influence over critical facets of plant biology such as flowering, fruit ripening, and seed development. OBJECTIVE: This study aims to identify ACO genes from representative Rosaceae genomes, reconstruct their phylogenetic relationships by integrating synteny information, and investigate their expression patterns and networks during fruit development. METHODS: we utilize a specialized Hidden Markov Model (HMM), crafted on the sequence attributes of ACO gene-encoded proteins, to systematically identify and analyze ACO gene family members across 12 representative species within the Rosaceae botanical family. Through transcriptome analysis, we delineate the expression patterns of ACO genes in six distinct Rosaceae fruits. RESULTS: Our investigation reveals the presence of 62 ACO genes distributed among the surveyed Rosaceae species, characterized by hydrophilic proteins predominantly expressed within the cytoplasm. Phylogenetic analysis categorizes these ACO genes into three discernible classes, namely Class I, Class II, and Class III. Further scrutiny via collinearity assessment indicates a lack of collinearity relationships among these classes, highlighting variations in conserved motifs and promoter types within each class. Transcriptome analysis unveils significant disparities in both expression levels and trends of ACO genes in fruits exhibiting respiratory bursts compared to those that do not. Employing Weighted Gene Co-Expression Network Analysis (WGCNA), we discern that the co-expression correlation of ACO genes within loquat fruit notably differs from that observed in apples. Our findings, derived from Gene Ontology (GO) enrichment results, signify the involvement of ACO genes and their co-expressed counterparts in biological processes linked to terpenoid metabolism and carbohydrate synthesis in loquat. Moreover, our exploration of gene regulatory networks (GRN) highlights the potential pivotal role of the GNAT transcription factor (Ejapchr1G00010380) in governing the overexpression of the ACO gene (Ejapchr10G00001110) within loquat fruits. CONCLUSION: The constructed HMM of ACO proteins offers a precise and systematic method for identifying plant ACO proteins, facilitating phylogenetic reconstruction. ACO genes from representative Rosaceae fruits exhibit diverse expression and regulative patterns, warranting further function characterizations.
RESUMO
Transposable elements (TEs) exert significant influence on plant genomic structure and gene expression. Here, we explored TE-related aspects across 14 Rosaceae genomes, investigating genomic distribution, transposition activity, expression patterns, and nearby differentially expressed genes (DEGs). Analyses unveiled distinct long terminal repeat retrotransposon (LTR-RT) evolutionary patterns, reflecting varied genome size changes among nine species over the past million years. In the past 2.5 million years, Rubus idaeus showed a transposition rate twice as fast as Fragaria vesca, while Pyrus bretschneideri displayed significantly faster transposition compared with Crataegus pinnatifida. Genes adjacent to recent TE insertions were linked to adversity resistance, while those near previous insertions were functionally enriched in morphogenesis, enzyme activity, and metabolic processes. Expression analysis revealed diverse responses of LTR-RTs to internal or external conditions. Furthermore, we identified 3695 pairs of syntenic DEGs proximal to TEs in Malus domestica cv. 'Gala' and M. domestica (GDDH13), suggesting TE insertions may contribute to varietal trait differences in these apple varieties. Our study across representative Rosaceae species underscores the pivotal role of TEs in plant genome evolution within this diverse family. It elucidates how these elements regulate syntenic DEGs on a genome-wide scale, offering insights into Rosaceae-specific genomic evolution.