Identification and expression analysis of miRNA-mRNA regulatory modules related to lipid accumulation in Camellia...

Camellia drupifera is an economically important woody oil crop. During seed maturation, complex physiological changes occur, predominantly involving lipid accumulation. The modulation of specific miRNAs can regulate multiple unigenes involved in seed development and fatty acid biosynthesis, thereby altering seed oil content. In this study, we performed transcriptome and small RNA sequencing of C. drupifera seeds at three developmental stages. Our integrated analysis identified 22,292 differentially expressed unigenes (DEGs), 251 known miRNAs, and 343 novel miRNAs. Target prediction analysis revealed 407 DEGs potentially regulated by 112 miRNAs, demonstrating the complexity of the regulatory network. Furthermore, we identified 8 key miRNA-mRNA modules potentially involved in lipid metabolism. Functional enrichment analysis showed these target unigenes were primarily associated with fatty acid metabolism, unsaturated fatty acid biosynthesis, α-linolenic acid metabolism, and glycerolipid metabolism pathways. Our findings provide comprehensive insights into the miRNA-mediated regulatory network during C. drupifera seed maturation and establish a molecular foundation for genetic improvement of this oil crop.