Aug 2026· Pest Management Science· 0 citations· 44 references
Medicine
TL;DR
Findings provide insights into the potential multifaceted insecticidal action of benzothiazole in T. castaneum at the transcriptomic level and support its further development as a target-specific grain fumigant.
Abstract
Background
Benzothiazole has been identified as a potential grain fumigant against Tribolium castaneum, though its insecticidal mechanism requires further investigation. In this study, sixth-instar larvae of T. castaneum were exposed to benzothiazole at LC30 and LC50 concentrations for 24 h.
Results
Neither concentration caused sustained inhibition of larval respiratory rate, ATP content, or mitochondrial membrane potential over the 24 h exposure period. RNA-seq analysis identified 392 differentially expressed genes common to both LC30 (50.96 μL L-1) and LC50 (108.86 μL L-1) treatments. Protein-protein interaction analysis of these shared genes revealed three core genes all encoding 4-coumarate-CoA ligase (4CL). In larvae, benzothiazole exposure upregulated genes in pathways related to protein digestion and absorption, juvenile hormone hydrolysis, detoxification and cuticle formation, but downregulated genes in carbohydrate metabolism. Among the key genes involved, UDP-glucuronosyltransferases (UGTs) participated in multiple enriched pathways and emerged as a common responsive gene family in both T. castaneum and the Dipteran insect Bradysia odoriphaga. RNAi-mediated silencing of UGT2B9, 4CL, or extensin demonstrated that only knockdown of UGT2B9 significantly increased larval susceptibility to benzothiazole.
High-temperature stress impairs plant growth and alters secondary metabolism. Polymethoxyflavones (PMFs) are citrus-specific flavonoids with important nutritional benefits; however, their transcriptional responses to heat stress remain poorly understood. Here, five-month-old ‘Ponkan’ citrus seedlings were exposed to 40 °C for 6, 11, and 21 days. HPLC analysis showed that the accumulation of four major PMFs (sinensetin, nobiletin, tangeretin, and 5-demethylnobiletin) was significantly reduced in leaves under heat stress. RNA-seq identified 3424 differentially expressed genes shared across all three time points, which were enriched in pathways associated with microtubule cytoskeleton organization, cell cycle regulation, and glyoxylate and dicarboxylate metabolism. Further analysis of the PMF biosynthetic pathway revealed that 14 of 18 key structural genes, including CHS, CHI, FNSII, and OMT family members, were downregulated by heat treatment. In addition, several bHLH, AP2/EREBP, and MYB transcription factors, known regulators of flavonoid biosynthesis, exhibited expression patterns closely associated with PMF accumulation. RT-qPCR analysis validated the transcriptome results. Collectively, these findings suggest that heat stress suppresses PMF accumulation through coordinated repression of PMF biosynthetic genes and their potential regulators. This study provides new insights into the molecular basis of heat-responsive PMF metabolism and offers potential targets for maintaining citrus nutritional quality under elevated temperatures.
Xiaojuan Liu, Zhenkun Liao, Honglu Hu et al.· Horticulturae· 0 citations
Background: Imidacloprid, a widely used neonicotinoid insecticide, is routinely applied to control pests in Astragalus membranaceus var. mongholicus, a crucial medicinal herb producing Astragali Radix. However, the early short-term transcriptional and metabolic responses of its seedlings under imidacloprid gradient stress remain poorly characterized. Methods: In this study, 80-day seedlings were subjected to three foliar spray treatments: blank control (CK), the recommended imidacloprid concentration (2000-fold dilution, 475 mg·L−1), and an excessively high concentration (500-fold dilution, 1900 mg·L−1). Leaf samples were harvested 24 h post-treatment for untargeted ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) metabolomics (6 biological replicates) and RNA-seq transcriptome sequencing (3 biological replicates). Results: The low- and high-dose treatments induced 1076 and 860 differential metabolites and 6818 and 7283 differentially expressed genes, respectively. Flavonoids, saponins, terpenoids, amino acid metabolites, and energy-related pathways were prominently affected. KEGG enrichment indicated activation of flavone/flavonol biosynthesis, phenylpropanoid metabolism, amino acid metabolism, MAPK signaling, cutin/suberin/wax biosynthesis, and ABC transporter pathways, whereas high-dose exposure was associated with stronger changes in genes related to DNA replication and cell wall remodeling. Integrated network analysis highlighted CHS, PAL, MYC2, KCS, and ABCG40 as candidate regulators linking stress signaling, secondary metabolism, and metabolite transport. Conclusions: Seedlings of A. membranaceus var. mongholicus exhibit dose-dependent acute responses to imidacloprid. Moderate pesticide exposure primarily activates defensive secondary metabolism, whereas excessive dosage triggers genome-wide transcriptional reprogramming. This work identifies key metabolic pathways and hub genes, offering candidate molecular markers for investigating pesticide stress adaptation in medicinal Astragalus and guiding standardized pesticide application in cultivation.
Dabao Yin, Xue Li, Li Zhou et al.· Genes· 0 citations
This study clarifies the molecular basis and transcriptional regulation of phenolic acid glycosylation in P. chienii, providing a framework for exploiting its medicinal resources and guiding conservation-oriented breeding.
Xiaori Zhan, Zijing Zhou, Yuting Peng et al.· Plant and Cell Physiology· 1 citation
Simple Summary Liriomyza trifolii is recognized as a destructive invasive pest affecting vegetable and ornamental crops worldwide, including China, where prolonged chemical insecticide use has led to reduced efficacy. In this study, the potential of bitter gourd (Momordica charantia) leaf extract as a botanical alternative was investigated. Host suitability tests demonstrated that L. trifolii exhibited significant oviposition and feeding adaptability for kidney bean over bitter gourd, with complete life cycle failure observed on the latter. Application of ethanol extracts resulted in dose-dependent adulticidal activity. At the LC50 concentration, feeding punctures and oviposition were notably reduced, and egg hatching and larval survival were significantly decreased, whereas pupation and emergence were not markedly affected. Integrative transcriptomic and metabolomic analyses were subsequently performed to elucidate underlying mechanisms, revealing 254 differentially expressed genes and 272 differential metabolites. Joint pathway analysis identified “Biosynthesis of amino acids” as the sole common pathway, with notable associations involving S-adenosyl-L-homocysteine, N-succinyl-LL-2,6-diaminoheptanedioate, and glutamine synthetase. These findings suggest that the reprogramming of amino acid and nitrogen metabolism may participate in the treatment response and could serve as a candidate response pathway. As such, this pathway may provide a theoretical basis for future development of plant-derived insecticides against L. trifolii.
Corynespora leaf spot, caused by Corynespora cassiicola, is an emerging disease in crops that significantly impacts both yield and quality. Currently, the use of fungicides to control Corynespora leaf spot has led to the development of varying degrees of resistance in the pathogen. Therefore, it is crucial to screen for highly effective fungicides with novel modes of action. This study evaluated the antifungal activity of 1-hydroxyphenazine (1OH-PHZ) against multiple phytopathogenic fungi, with a half-maximal effective concentration (EC50) of 19.23 μg/ml against C. cassiicola hyphae. In vivo assay demonstrated antifungal activity of 67.22 and 45.03% on detached tomato leaves and fruits, respectively, at a dose of 500.0 μg/ml. Microscopic and ultrastructural observations revealed hyphal collapse, surface wrinkling, and indistinct organelle boundaries following treatment. Integrated transcriptomic and metabolomic analyses showed differentially expressed genes and differentially abundant metabolites, primarily affecting amino acid metabolism and biosynthesis pathways. Molecular docking, dynamic simulations, and microscale thermophoresis assays demonstrated that 1OH-PHZ binds to PLP-dependent transferase (PLPDT), exhibiting a binding free energy of -7.2 kcal/mol and a dissociation constant (Kd) value of 1.16 μM. Collectively, these findings suggest that 1OH-PHZ potentially binds to PLPDT, thereby disrupting amino acid metabolism and biosynthesis, which subsequently affects the synthesis and morphological development of the fungal cell wall and cell membrane. Through the combination and screening of highly active fungicidal substances, this study offers mechanistic insights that support the potential development of 1OH-PHZ as a novel agricultural fungicide for managing C. cassiicola infections.
Dongxue Li, Haowen Ni, Yuqi Bin et al.· Phytopathology· 0 citations