Elm (Ulmus) species are important components of forest resources with significant ecological and economic value. As tall hardwood trees that are drought-resistant, poor-soil-tolerant, and highly adaptable, Ulmus species are an excellent choice for ecologically protected forests and urban landscaping. Additionally, the bioactive substances identified in the fruits, leaves, bark, and roots of Ulmus have potential applications in the food and medical fields and as raw materials in industrial and cosmetic applications. However, the survival of Ulmus species in the natural environment has been threatened by recurrent outbreaks of Dutch elm disease, which have led to the death of large numbers of Ulmus trees. In addition, severe damage to the natural habitats of some Ulmus species is driving their populations to extinction. Omics technology has become an important tool for the collection, protection, and biological characteristic analysis of Ulmus species and their resources due to its recent advances. This article summarizes the current research and application status of omics technology in Ulmus. The remaining problems are noted, and future research directions are proposed. Our review is aimed at providing a reference for resource conservation of Ulmus and for scientific research into this genus.

BACKGROUND: Spodoptera litura is one of the most harmful lepidoptera pests in China, and is difficult to control due to its strong resistance to the current frequently used insecticide species. The requirement to develop pesticides with novel toxicology mechanisms to control S. litura is urgent. The quassinoid of bruceine D display outstanding systemic properties and strong insecticidal activity against S. litura, which possess notable application potential for integrative management of S. litura, but the mechanism of toxicity remains unclear. RESULTS: In this study, we found that bruceine D exerts potent growth inhibitory activity against S. litura, disrupting the ecdysone and juvenile hormone titers, and causing long-term adverse effects. Association analysis between transcriptomics and metabolomics suggested that bruceine D affected the digestion and absorption capacity of S. litura larvae by inducing a strong oxidative stress response and cell apoptosis in the intestine. Further analysis demonstrated that bruceine D can inhibit the activities of digestive and antioxidant enzymes and induce malondialdehyde (MDA) and reactive oxygen species (ROS) overaccumulation in the midgut. Moreover, the protein level of Bax, cleavage caspase 3, and cytochrome c expressed in cytoplasm (cyto) were up-regulated by bruceine D, while Bcl-2 and cytochrome c expressed in mitochondria (mito) were down-regulated. In addition, there was a noticeable increase in caspase-3 protease activity. Histopathological observations revealed that bruceine D damages the structure of midgut epithelial cells and activates lysosomes, which subsequently disrupts the midgut tissue. CONCLUSION: Overall, our findings suggested that bruceine D induced excessive ROS accumulation in midgut epithelial cells. The resulting cell apoptosis disrupted midgut tissue, leading ultimately to reduced nutrient digestion and absorption in the midgut and the inhibition of larval growth. (c) 2024 Society of Chemical Industry.