Endophytes have been recognized as important sources for discovering novel bioactive natural products with diverse structures and biological activities. This review focuses on the endophytes of Tripterygium wilfordii Hook. f. (T. wilfordii), a famous traditional medicinal plant, and summarizes the producing microbes, chemical diversities, and bioactivities of the metabolites discovered from the T. wilfordii ‐associated endophytes over the past thirty years (1995‐2024). One hundred and one metabolites together with their bioactivities from twelve endophytes are systematically reviewed. A comprehensive comparison of the 101 metabolites with those isolated from T. wilfordii reveals that the T. wilfordii‐associated endophytes produce structurally distinct metabolites with diverse biological activities. To the best of our knowledge, this is the first holistic overview of the T. wilfordii‐associated endophytes and their secondary metabolites.
Hydrogel biosensors present numerous advantages in food safety analysis owing to their remarkable biocompatibility, cargo-loading capabilities and optical properties. However, the current drawbacks (slow target responsiveness and poor mechanical strength) restricted their further utilization at on-site detection of targets. To address these challenges, a DNA-functionalized cryogel with hierarchical pore structures is constructed to improve the reaction rate and the robustness of hydrogel biosensor. During cryogel preparation, ice crystals serve as templates, shaping interconnected hierarchical microporous structures to enhance mass transfer for faster responses. Meanwhile, in the non-freezing zone, concentrated monomers create a dense cross-linked network, strengthening cryogel matrix strength. Accordingly, a colorimetric biosensor based on DNA cryogel has been developed as a proof of concept for rapid detection of aflatoxin B1 (AFB1) in food samples, and an excellent analytical performance was obtained under the optimized conditions with a low detection limit (1 nM), broad detection range (5-100 nM), satisfactory accuracy and precision (recoveries, 81.2-112.6%; CV, 2.75-5.53%). Furthermore, by integrating with a smartphone sensing platform, a portable device was created for rapid on-site measurement of target within 45 minutes, which provided some insight for hydrogel biosensors design.
Arabidopsis AVRPPHB SUSCEPTIBLE1 (PBS1) serves as a "decoy" in activating RESISTANCE TO PSEUDOMONAS SYRINGAE5 (RPS5) upon cleavage by Pseudomonas phaseolicola B (AvrPphB), a Pseudomonas syringae effector. The SEMPH motif in PBS1 was thought to allow it to be distinguished by RPS5 from the closely related Arabidopsis kinases. However, the underlying mechanism is not fully understood. Here, we isolated and characterized a wheat PBS1 homolog, TaPBS1. Although this plasma membrane-localized kinase could be cleaved by AvrPphB and could associate with RPS5, it failed to trigger RPS5-mediated hypersensitive response (HR) in a transient assay. TaPBS1 harbors a STRPH motif. The association of RPS5 with TaPBS1 was weaker than with PBS1. Change of the STRPH motif to the SEMPH motif allowed TaPBS1 to trigger HR. However, the SEMPH motif is not required for association of PBS1 with RPS5. The difference between "SEMPH" and "STRPH" points to the importance of "EM" in PBS1. Furthermore we found that a negatively charged amino acid at the position of "E" in the SEMPH motif was required for recognition of PBS1 by RPS5. Additionally, both PBS1 and TaPBS1 undergo the flagellin-induced phosphorylation. Therefore, our work will help understand the mechanism of PBS1 functioning in plant innate immunity.
A RP-HPLC method was established for the simultaneous determination of puerarin, daidzin and daidzein in roots, stems and leaves of Pueraria lobata (Wild) Ohwi. The procedure was based on extraction of test portions with 70% ethanol solution in an ultrasonic field for 20 min at 50 ℃ followed by direct HPLC analysis of the extracts. The chromatographic conditions were as follows: using a Hypersil ODS-2 column (4.6 mm × 250 mm, 5 μm) and a mobile phase composed of methanol and H2O, gradient elution [0-4 min 25:75 (methanol/water volume ratio), 4-7 min 25:75 → 32:78, 7-9min 32:68, 9-11 min 32:68 → 50:50, 11-24 min 50:50, 24-30 min 50:50 → 25:75], column temperature 35 ℃, detection wavelength 250 nm, and flow rate of the mobile phase 0.8 ml/min. A good linear relationship between peak area and concentration was found to puerarin, daidzin and daidzein in the ranges of 11.87-73.91 (r = 0.9998), 1.00-6.48 (r = 0.9997) and 0.28-1.53 μg/ml (r = 0.9994), respectively. The LODs were 0.43, 0.24 and 0.18μg/ml, respectively. Mean recoveries were 99.78%, 102.61% and 105.57% with the RSDs of 1.6%, 2.8% and 3.4% (n = 5), respectively. The precision, stability and reproducibility of the method all were good. The contents of puerain, daidzin, and daidzein in roots of Pueraria lobata (wild) Ohwi determined by this method were 3.98%, 0.36% and 0.039% respectively, higher than 3.28%, 0.26% and 0.028% of those analyzed according to the method stipulated in the Chinese Pharmacopoeia 2005 respectively, suggesting high efficiency of ultrasonic-assisted extraction of the three analytes. The contents of puerain, daidzin, and daidzein in stems of Pueraria lobata (wild) Ohwi were 0.004%, 0.0032% and 0.0007% respectively, while those in leaves were 0.0016%, 0.005% and 0.0012%, respectively. This method is accurate, fast and simple and therefore can be used for the simultaneous determination of puerain, daidzin, and daidzein in roots, stems and leaves of Pueraria lobata (wild) Ohwi. Our results demonstrate that the contents of puerain, daidzin, and daidzein in stems and leaves of Pueraria lobata (wild) Ohwi growned in Maoshan area of Jiangsu province are obviously lower than those in the roots.
Legume root nodules convert atmospheric nitrogen gas into ammonium through symbiosis with a prokaryotic microsymbiont broadly called rhizobia. Auxin signaling is required for determinant nodule development; however, the molecular mechanism of auxin-mediated nodule formation remains largely unknown. Here, we show in soybean (Glycine max) that the microRNA miR167 acts as a positive regulator of lateral root organs, namely nodules and lateral roots. miR167c expression was up-regulated in the vasculature, pericycle, and cortex of soybean roots following inoculation with Bradyrhizobium japonicum strain USDA110 (the microsymbiont). It was found to positively regulate nodule numbers directly by repressing the target genes GmARF8a and GmARF8b (homologous genes of Arabidopsis [Arabidopsis thaliana] AtARF8 that encode auxin response factors). Moreover, the expression of miR167 and its targets was up- and down-regulated by auxin, respectively. The miR167-GmARF8 module also positively regulated nodulation efficiency under low microsymbiont density, a condition often associated with environmental stress. The regulatory role of miR167 on nodule initiation was dependent on the Nod factor receptor GmNFR1α, and it acts upstream of the nodulation-associated genes NODULE INCEPTION, NODULATION SIGNALING PATHWAY1, EARLY NODULIN40-1, NF-YA1 (previously known as HAEM ACTIVATOR PROTEIN2-1), and NF-YA2. miR167 also promoted lateral root numbers. Collectively, our findings establish a key role for the miR167-GmARF8 module in auxin-mediated nodule and lateral root formation in soybean.
A novel three-phase hollow fiber liquid phase microextraction was developed for the determination of malachite green (MG) in environmental waters, which selected [BMIM][$PF_6$] mixed with 1% trioctylphosphine oxide (TOPO) as supported phase. Several parameters (accepter phase pH, sample pH, supported phase membrane, volume of accepter phase, salinity, extraction time) that could affect extraction performance were investigated. Under the optimal extraction conditions, the established approach showed excellent characters as: high enrichment factor (212), wide linear range ($0.20-100{\mu}gL^{-1}$), low detection limit ($0.01{\mu}gL^{-1}$), good reproducibility (RSD, 8.9%, n=5) and satisfactory recovery (84.0-106.2%). The method was applied to detect MG at Yangtze River and pond waters in Zhenjiang, Jiangsu province, and 4 sites among 15 sampling sites were found MG with the concentration of $1.73-11.06{\mu}gL^{-1}$, which confirmed that the proposed environmentally friendly method was simple and effective for monitoring MG in aquatic system.
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