The research, led by Xiaoyu Zhang, Kaiyun Fu, and colleagues at the Xinjiang Academy of Agricultural Sciences together with collaborators at the Chinese Academy of Sciences, focused on a class of regulatory molecules known as competing endogenous RNAs, or ceRNAs. The ceRNA hypothesis proposes that different RNA transcripts, including messenger RNAs that encode proteins as well as non-coding RNAs that do not, can communicate with one another by competing for the same microRNA molecules. MicroRNAs are short RNA fragments that bind to complementary sequences on target transcripts and suppress their activity. When a non-coding RNA sponges up a shared microRNA, it effectively shields other transcripts from repression, creating a regulatory network in which abundance of one RNA can indirectly control the expression of many others.

To map this network in a starving insect, the team performed whole-transcriptome sequencing on T. absoluta larvae under two conditions: larvae feeding on fresh tomato leaves and larvae subjected to starvation. By comparing the complete repertoire of expressed molecules between the two groups, they identified a striking number of differentially expressed transcripts. In total, the analysis revealed 46 differentially expressed microRNAs, 2,143 differentially expressed messenger RNAs, 391 differentially expressed long non-coding RNAs, and 1,635 differentially expressed circular RNAs. Circular RNAs, which are formed when RNA strands are joined head-to-tail into closed loops, are particularly stable molecules and have emerged as potent microRNA sponges in many organisms, making their large-scale differential expression especially noteworthy.

With these differential expression profiles in hand, the researchers constructed putative regulatory networks linking the different RNA classes. Using computational prediction of binding sites combined with expression correlation analyses, they built both lncRNA–miRNA–mRNA and circRNA–miRNA–mRNA interaction networks. These networks represent hypotheses about which non-coding RNAs might be titrating away which microRNAs, and consequently which protein-coding genes might be released from repression or placed under additional control during starvation. The scale of the networks suggests that ceRNA-mediated crosstalk is a substantial component of the leafminer’s stress response rather than a marginal curiosity.

Functional enrichment analysis of the genes embedded in these networks provided the first clues about what the regulation is actually accomplishing. The differentially expressed messenger RNAs, the predicted microRNA target genes, and the host genes that give rise to circular RNAs were predominantly associated with chitin metabolism, lipid catabolism, fatty acid biosynthesis, and detoxification pathways. Each of these categories makes biological sense for a starving insect. Chitin is the structural polymer of the insect cuticle and gut lining, and its remodeling may reflect the physiological strain of fasting. Lipid catabolism and fatty acid metabolism are the classic fallback energy pathways when dietary carbohydrates and proteins run out, allowing the animal to mobilize stored fat reserves. Detoxification pathways, meanwhile, may help the insect cope with the metabolic byproducts of starvation or maintain its chemical defenses.

Deeper pathway analysis using the Kyoto Encyclopedia of Genes and Genomes reinforced this metabolic picture. Significant enrichment was observed in AMPK signaling, a conserved cellular energy-sensing pathway that switches on when intracellular energy levels fall and orchestrates the shift from energy consumption to energy production. Insulin signaling was also enriched, reflecting its central role in coordinating growth, nutrient storage, and mobilization in response to nutritional state. The biosynthesis of unsaturated fatty acids appeared as another significantly enriched pathway, consistent with the idea that starving larvae adjust the composition of their membrane lipids and fuel reserves to survive the crisis. Together, these pathways sketch a coherent strategy: sense the energy deficit, reroute metabolism toward stored fats, and adjust cellular infrastructure accordingly.

Perhaps the most striking single finding is the identification of two microRNAs, miR-6497a and miR-6498-5p, as putative key regulatory hubs within the ceRNA network. These two microRNAs were predicted to interact with multiple differentially expressed long non-coding RNAs, circular RNAs, and messenger RNAs simultaneously, placing them at the center of a dense web of potential crosstalk. In the ceRNA framework, a hub microRNA whose binding is contested by many sponges can exert broad, condition-dependent control over entire functional modules. If experimental work confirms these interactions, miR-6497a and miR-6498-5p would represent master switches that help determine how the leafminer’s metabolism is reconfigured when food disappears.

The study’s significance extends well beyond basic biology. Tuta absoluta, native to South America, has spread rapidly across Europe, Africa, and Asia since its initial invasions and remains a persistent threat to tomato production worldwide. Its capacity to survive unfavorable conditions, including gaps in food availability between crops or during dispersal, contributes to its invasive success and complicates control efforts. Current management relies heavily on chemical insecticides, against which the species has already evolved resistance to multiple modes of action. This has intensified interest in RNA interference as an alternative: double-stranded RNA molecules can be designed to silence essential pest genes with high specificity, and several RNAi-based products are in development for agricultural use. The ceRNA networks described in this study offer a catalog of candidate targets, particularly the hub microRNAs and the non-coding RNAs that regulate them, whose disruption could impair the pest’s ability to withstand starvation and other stresses encountered in the field.

The work also adds to a growing appreciation that non-coding RNAs are not background noise but active participants in how organisms respond to their environments. Long non-coding RNAs and circular RNAs have been implicated in stress responses in many species, but their roles in agricultural insect pests remain poorly charted. By integrating all four major RNA classes in a single analysis, the researchers demonstrated a methodology that other pest biologists can replicate, connecting transcriptome-wide discovery with functional interpretation. The authors caution that the networks are putative, resting on computational prediction and expression correlation, and that experimental validation will be needed to confirm individual interactions and to test whether manipulating these RNAs genuinely compromises the insect’s stress tolerance.

Even so, the study marks an important step in the molecular dissection of one of agriculture’s most notorious adversaries. It shows that when the tomato leafminer goes hungry, it does not simply slow down; it activates a coordinated, multi-layered RNA regulatory program that touches energy sensing, fat metabolism, structural remodeling, and detoxification all at once. Understanding that program in detail, and learning to break it, could give crop scientists a much-needed new angle of attack against a pest that has repeatedly outmaneuvered conventional control methods. For now, the humble non-coding RNA molecules once dismissed as transcriptional clutter have emerged as promising new players in the ongoing arms race between farmers and the insects that threaten their harvests.

Subject of Research: ceRNA regulatory networks in Tuta absoluta adaptation to starvation stress

Article Title: Integrated whole‑transcriptome analysis reveals ceRNA regulatory networks underlying Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) adaptation to starvation stress

Article References: Zhang, X., Wen, Y., Jia, Z., Wang, X., Wu, J., Ding, X., Guo, W., & Fu, K. (2026). Integrated whole‑transcriptome analysis reveals ceRNA regulatory networks underlying Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) adaptation to starvation stress. BMC Genomics. https://doi.org/10.1186/s12864-026-13273-x

Image Credits: AI Generated

DOI: 10.1186/s12864-026-13273-x

Keywords: Tuta absoluta, tomato leafminer, ceRNA, non-coding RNAs, microRNAs, lncRNAs, circRNAs, starvation stress, transcriptomics, AMPK signaling, lipid metabolism, RNAi pest control