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Anthracnose caused by Colletotrichum gloeosporioides critically threatens the growth and commercial cultivation of Sarcandra glabra. However, the defence responses and underlying mechanisms remain unclear. Herein, we aimed to investigate the molecular reprogramming in S. glabra leaves infected with C. gloeosporioides. Leaf tissues at 0, 24 and 48 h post-inoculation (hpi) were analysed by combining RNA sequencing and Tandem Mass Tag-based liquid chromatography with tandem mass spectrometry. In total, 18 441 and 25 691 differentially expressed genes were identified at 24 and 48 hpi compared to 0 hpi (uninoculated control), respectively. In addition, 1240 and 1570 differentially abundant proteins were discovered at 24 and 48 hpi compared to 0 hpi, respectively. Correlation analysis revealed that transcription and translation levels were highly consistent regarding repeatability and expression. Analyses using databases KEGG and iPATH revealed tricitric acid cycle, glycolysis/gluconeogenesis and phenylpropanoid biosynthesis were induced, whereas photosynthesis and tryptophan were suppressed. Enzymatic activity assay results were consistent with the upregulation of defence-related enzymes including superoxide dismutases, catalases, peroxidases and chitinases. The transcriptome expression results were additionally validated by quantitative real-time polymerase chain reaction analyses. This study provides insights into the molecular reprogramming in S. glabra leaves during infection, which lay a foundation for investigating the mechanisms of host- Colletotrichum interactions and breeding disease-resistant plants. Anthracnose caused by Colletotrichum gloeosporioides critically threatens the growth and commercial cultivation of the medicinal plant Sarcandra glabra. We explored the molecular changes during the early stages of this infection through systems biology. This study provides insights into the molecular reprogramming in S. glabra leaves during infection, which lay a foundation for investigating the mechanisms of host -Colletotrichum interactions and breeding disease-resistant plants. [ABSTRACT FROM AUTHOR]

The safety of medicinal herbs is critical to human health, and the monitoring of pesticide residues in medicinal herbs is necessary. In the present study, a direct competitive enzyme-linked immunosorbent assay (dc-ELISA) was developed for the determination of imidacloprid in medicinal herbs. Using the optimal conditions, the 50% inhibiting concentration and detection range (20–80% inhibiting concentration) of the established dc-ELISA were 0.08 and 0.03–0.29 ng/mL, respectively. Except for clothianidin (4.64%) and acetamiprid (2.52%), the cross-reactivity with analyte analogs was negligible. In purple perilla, cordate houttuynia, water lily, bitter melon, and mung bean, the average imidacloprid recoveries were from 62.97 to 134.09%, with relative standard deviations between 0.21 and 14.58%. Furthermore, the immunoassay results correlated well with spiked samples analyzed by high-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS). The established immunoassay is rapid, sensitive, and specific and suitable to monitor imidacloprid residues in medicinal herbs. [ABSTRACT FROM AUTHOR]

Centella asiatica (L.) Urban is a well-known medicinal plant which has multiple pharmacological properties. Notably, the leaves of C. asiatica contain large amounts of triterpenoid saponins. However, there have only been a few studies systematically elucidating the metabolic dynamics and transcriptional differences regarding triterpenoid saponin biosynthesis during the leaf development stages of C. asiatica. Here, we performed a comprehensive analysis of the metabolome and transcriptome to reveal the dynamic patterns of triterpenoid saponin accumulation and identified the key candidate genes associated with their biosynthesis in C. asiatica leaves. In this study, we found that the key precursors in the synthesis of terpenoids, including DMAPP, IPP and β-amyrin, as well as 22 triterpenes and eight triterpenoid saponins were considered as differentially accumulated metabolites. The concentrations of DMAPP, IPP and β-amyrin showed significant increases during the entire stage of leaf development. The levels of 12 triterpenes decreased only during the later stages of leaf development, but five triterpenoid saponins rapidly accumulated at the early stages, and later decreased to a constant level. Furthermore, 48 genes involved in the MVA, MEP and 2, 3-oxidosqualene biosynthetic pathways were selected following gene annotation. Then, 17 CYP450s and 26 UGTs, which are respectively responsible for backbone modifications, were used for phylogenetic-tree construction and time-specific expression analysis. From these data, by integrating metabolomics and transcriptomics analyses, we identified CaHDR1 and CaIDI2 as the candidate genes associated with DMAPP and IPP synthesis, respectively, and CaβAS1 as the one regulating β-amyrin synthesis. Two genes from the CYP716 family were confirmed as CaCYP716A83 and CaCYP716C11 . We also selected two UGT73 families as candidate genes, associated with glycosylation of the terpenoid backbone at C-3 in C. asiatica . These findings will pave the way for further research on the molecular mechanisms associated with triterpenoid saponin biosynthesis in C. asiatica ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wan, Huang, Li, Yu, Tan, Wei, El-Sappah, Sooranna, Zhang, Pan, Zhang and Lei.)