# 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.

## Key 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.