Elucidating Cold-Stress-Induced Metabolic and Transcriptional Reprogramming in Tuta absoluta Larvae Through...

Exposure to stressful low temperatures during development can cause chilling injury, leading to impaired physiological performance. In insects, chilling injury is often associated with metabolic imbalance, oxidative stress and disruption of energy homeostasis, which can collectively compromise survival and growth. Because Tuta absoluta (Meyrick, 1917) is a tomato pest adapted to warm environments, we hypothesized that low-temperature exposure would induce chilling injury by disrupting metabolism and cellular function. We investigated the responses of T. absoluta larvae to three thermal regimes (25, 15 and 5 °C) over a 7-day period, using integrated physiological, metabolomic and transcriptomic analysis. Low-temperature stress reduced survival and feeding performance, accompanied by suppressed digestive enzyme activities (α-amylase, lipase and trypsin) and depletion of glycogen reserves, indicating impaired energy acquisition. In contrast, increased trehalose and proline accumulation suggested a shift toward protective metabolism. Importantly, low temperature induced a pronounced decoupling of energy metabolism and redox homeostasis, characterized by reduced antioxidant capacity (peroxidase; POD and superoxide dismutase; SOD) and elevated levels of reactive oxygen species (ROS). Metabolomic and transcriptomic analysis of stressed larvae revealed alterations in amino acid and carbohydrate metabolism, showing differential regulation of the genes involved in energy production, oxidative stress responses and growth. Integrative analysis demonstrated that metabolic reprogramming and transcriptional regulation are tightly linked under low-temperature conditions, revealing a resource allocation trade-off between growth and stress defense. Together, these findings identify metabolic and redox imbalances as mechanisms underlying cold-induced physiological decline, providing new insight into how low temperature constrains insect performance.