Integration of Transcriptome, miRNA-Omics, and Hormone Metabolism Analysis Reveals the Regulatory Network of Camellia drupifera Fruit Maturation

TL;DR

This study explores how hormones, genes, and miRNAs work together to regulate fruit maturation in Camellia drupifera, an important oil crop.

Contribution

The study identifies a novel 'hormone–miRNA–mRNA' regulatory network involved in fruit maturation and lipid accumulation in Camellia drupifera.

Findings

IAA and GA3 levels peak during early fruit development, promoting growth via genes like AUX1 and ARF.

ABA levels rise during maturation, activating genes like PYR/PYL and ABF while IAA and GA3 decline.

miRNAs such as miR393-z and novel-m0146-5p regulate hormone signaling and fruit maturation processes.

Abstract

Camellia drupifera is an important woody oil crop with high economic and medicinal value. Fruit maturation is a complex process regulated by hormones and gene networks, yet its molecular basis remains unclear. Here, we integrated hormone profiling (IAA, GA3, ABA), transcriptomics, and miRNA-omics across three key stages: nutrient synthesis (S1), lipid accumulation (S4), and maturation (S7). During early development (S1), IAA and GA3 levels peaked, accompanied by the upregulation of growth-related genes (AUX1, ARF, GID1), which promote fruit growth. By maturation (S7), ABA content increased markedly, activating PYR/PYL, PP2C, and ABF, while IAA and GA3 declined. Transcriptome analysis revealed 45 key differentially expressed genes correlated with hormone levels. In parallel, miRNAs such as miR393-z (targeting TIR1) and novel-m0146-5p (targeting ARF1) were identified as regulators of hormone signaling and fruit maturation. Collectively, our results highlight a coordinated “hormone–miRNA–mRNA” regulatory network underlying C. drupifera fruit development. These findings provide new insights into the molecular regulation of fruit maturation and lipid accumulation in woody oil crops, offering a foundation for genetic improvement and efficient utilization of this species.

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