Introduction: Semiaphis heraclei is an important economic pest affecting Caprifoliaceae and Apiaceae plants, and chemical control is still the main effective control method in the field. Afidopyropen is a new type of pyridine cyclopropyl insecticide, which can effectively control piercing-sucking mouthparts pests and is suitable for pest resistance management. However, the detoxification mechanism of S. heraclei to afidopyropen is still poorly cleared.Methods: The insecticidal activity of afidopyropen against S. heraclei and the enzyme activity assay and synergism bioassay were evaluated. The detoxification enzyme genes were obtained by transcriptome and validated by quantitative real-time PCR (RT-qPCR). Furthermore, RNA interference was used to study the functions of detoxification enzyme genes.Results: The activities of cytochrome P450 monooxygenases (P450s) and carboxylesterases (CarEs) were significantly increased under afidopyropen treatment. The toxicity of afidopyropen against S. heraclei was significantly increased after application the inhibitors of piperonyl butoxide and triphenyl phosphate. Sixteen P450 genes and three CarE genes were identified in the transcriptome of S. heraclei. The RT-qPCR results showed that eleven P450 genes and two CarE genes were significantly upregulated under afidopyropen treatment, and the expression of CYP6DA2 and CarFE4 was upregulated by more than 2.5 times. The expression pattern of CYP6DA2 and CarFE4 was further analyzed in different developmental stages of S. heraclei and knockdown of CYP6DA2 and CarFE4 significantly increased the susceptibility of S. heraclei to afidopyropen.Conclusion: The results of this study uncover the key functions of CYP6DA2 and CarFE4 in the detoxification mechanism of S. heraclei to afidopyropen, and provide a theoretical basis for the scientific use of afidopyropen in the field.

This study aimed to analyze the effects of salt stress on the growth physiology and plant-cell ultrastructure of Isatis indigotica Fort. (I. indigotica) to evaluate its adaptability under salt stress. The effects of different concentrations of salt (NaCl; 0, 25, and 300 mmol·L⁻¹) on the agronomic traits, activities of related enzymes, ion balance, and mesophyll-cell ultrastructure of I. indigotica were studied in a controlled pot experiment. Results showed that compared with those of the control group, the aerial-part fresh weight, underground fresh weight, tiller number, root length, root diameter, plant height, and leaf area of salt-stressed I. indigotica increased at 25 mmol·L⁻¹ and then decreased at 300 mmol·L⁻¹. The changes in levels of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase showed a similar trend, with significant differences compared with control group. Salt stress altered the ion balance of I. indigotica, resulting in a significant increase in Na⁺ content and a significant decrease in K⁺ content. The contents of Ca²⁺ and Mg²⁺ changed to varying degrees. The analysis of the microstructure of the root showed that under salt treatment, the epidermal cells of the root significantly thickened and the diameter of the xylem decreased. The results of ultrastructural analysis of mesophylls showed that salt stress can cause cell-membrane contraction, cell-gap enlargement, disorder in the structures of chloroplasts and mitochondria, and an increase in the number of osmiophilic particles. These changes were aggravated by the increase in NaCl concentration. This study reveals the response of I. indigotica to salt stress and provides a basis for further study on the salt-tolerance mechanism of I. indigotica.

Background Shading is an important factor affecting the cultivation of American ginseng, as it influences crop quality and yield. Rhizosphere microorganisms are also crucial for normal plant growth and development. However, whether different shade types significantly change American ginseng rhizosphere microorganisms is unknown. Methods This study evaluated the rhizosphere soils of American ginseng under traditional, high flag and high arch shade sheds. High-throughput 16S rRNA gene sequencing determined the change of rhizosphere bacterial communities. Results The microbial diversity in rhizosphere soils of American ginseng significantly changed under different shading conditions. The bacteria diversity was more abundant in the high arch shade than flat and traditional shades. Different bacterial genera, including Bradyrhizobium, Rhizobium, Sphingomonas, Streptomyces and Nitrospira, showed significantly different abundances. Different shading conditions changed the microbial metabolic function in the American ginseng rhizosphere soils. The three types of shade sheds had specific enriched functional groups. The abundance of ATP-binding cassette (ABC) transporters consistently increased in the bacterial microbiota. These results help understand the influence of shading systems on the rhizosphere microecology of American ginseng, and contribute to the American ginseng cultivation.

The small brown planthopper (SBPH), Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae), is an increasing threat to Gramineae crops, posing significant risks to both the environment and food safety. β-asarone, as a promising green alternative to chemical insecticides, possesses wide application prospects in the crop protection field. To enhance the insecticidal activity of β-asarone, a series of derivatives were prepared through an active substructure splicing strategy, and their insecticidal activities against SBPH were evaluated. Among the 7 commercial compounds with chemical structures similar to β-asarone and 12 structural derivatives of β-asarone, compound 10, which incorporates the 2-chloropyridine functional group from flupyrimin, exhibited the most potent insecticidal activity against SBPH, with an 8.31-fold increase in insecticidal activity compared to β-asarone. Furthermore, transcriptome analysis showed that among the selected genes that may play important roles in insecticidal activity, an ABC transporter gene, MDR49, was most significantly down-regulated. MDR49 was highly expressed in the 4th-instar nymphs, with the highest expression level in the fat body, midgut, and abdomen. RNA interference (RNAi) against MDR49 significantly reduced susceptibility to compound 10 in SBPH, which revealed that MDR49 may be the candidate insecticidal target of compound 10. Additionally, the insecticidal spectrum revealed that compound 10 showed excellent efficacy against Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Tetranychus cinnabarinus (Boisduval) (Acarina: Tetranychidae). This study indicates that compound 10 could be further developed as a novel eco-friendly pesticide.

Introduction: Continuous cropping (CC) poses significant challenges to the yield and quality of Salvia miltiorrhiza, a medicinally important plant with annual market demand of around 20 million kg. Previous studies have explored chemical mitigation methods, but concerns persist regarding environmental pollution and safety issues.Methods: In this study, we evaluated three strains of the fungus Trichoderma (T. brevicompactum, T. viridescens, and T. velutinum) as ecofriendly alternatives for CC obstacle mitigation in S. miltiorrhiza cultivation.Results: The Trichoderma treatments significantly enhanced the relative abundance of beneficial soil bacteria (Actinobacteria 9.25%–16.88%; Chloroflexi 6.41%–16.73%; Gemmatimonadetes 1.21%–3.16%), while decreasing the abundance of pathogenic Fusarium by 12.67%–31.75%. Soil analysis revealed substantial improvements in total organic carbon (47.35%–65.88%), nitrate nitrogen (91.38%–318.89%), available potassium (4.29%–17.16%), and available phosphorus (1.85%–11.86%) following Trichoderma treatment. T. brevicompactum demonstrated superior performance among the three tested strains, increasing the individual plant fresh weight by 17.79% and the survival rate by 13.33%. This treatment also significantly elevated (p < 0.05) the content of key bioactive compounds in S. miltiorrhiza root: tanshinone IIA (51.16% increase), cryptotanshinone (56.76%), tanshinone I (50.00%), and salvianolic acid B (18.43%).Discussion: Trichoderma can effectively alleviate S. miltiorrhiza CC obstacles by improving the soil nutrient status and modulating the soil microbial community, thereby enhancing plant growth and stress resistance. This study provides a promising ecofriendly strategy for sustainable cultivation of S. miltiorrhiza and other medicinal plants facing similar challenges.