First Report of the Root-Knot Nematode Meloidogyne incognita on Bletilla striata Rchb.f. (Orchidaceae) in China.

Bletilla striata Rchb.f., is a perennial herbaceous bulbous plant known as the Chinese ground or hyacinth orchid classified in the Orchidaceae. It is native to southeast Asia and mainly distributed in China, Japan and northern Myanmar (He et al. 2017). It has the functions of astringent hemostasis and analgesia, and can also be used to treat traumatic bleeding, ulcers, swelling and chapped skin. Therefore, it occupies an important position in traditional Chinese medicine (Xu et al. 2019). In June 2023, three farmers in Mengzi (103.39°N, 23.21°E), Yunnan Province, China, observed that some Bletilla striata Rchb.f. plants grew poorly with small and chlorotic leaves (Figure 1 A). We suspected that these symptoms were caused by root-knot nematode infection, but the galls on the roots were small and inconspicuous (Figure 1 A). The presence of nematode females in both the galled regions and the normal roots (Figure 1 B), revealed by fuchsin staining (Byrd et al. 1983), indicated that the symptoms were probably caused by root-knot nematode infection. To estimate the incidence rates, we randomly selected 100 B. striata Rchb.f. plants from each of five fields representing a total area of 3000 m2. In these fields, the occurrence of stained root-knot nematodes were 19.3%, 17%, 18.3%, 15%, and 13%, respectively. The gall rating of the infected plants in the B striata Rchb.f. samples collected from the five fields was 2 (rating scale of 0 to 5). Females (n=20), second-stage juveniles (J2s, n=20) and egg masses (n=20) were extracted and collected from roots and soil for morphological and molecular identification. The females had a white, pyriform body and their perineal patterns exhibited a high and square dorsal arch, lacking distinct lateral line (Figure 1. C & D). Measurements of females (n = 20) were: body length (BL) = 708.64±89.6 µm (554.36 to 844.51 µm); maximum body width (BW) = 461.73±47.44 µm (365.25 to 561.49 µm); stylet length (ST) = 15.49±3.15 µm (10.55 to 19.78 µm); and distance from dorsal esophageal gland opening to the stylet knobs (DGO) = 3.33±0.27 µm (2.77 to 3.93 µm). Measurements of J2s (n=20) were BL = 417.7±47.67 µm (342.16 to 499.68 µm); BW = 15.74±2.66 µm (11.05 to 25.63 µm); ST = 12.49±1.12 µm (10.19 to 15.02 µm); DGO = 2.64±0.59 µm (40.17 to 68.74 µm); tail length = 51.93±8.55 µm (10.43 to 27.22 µm); hyaline tail terminus = 18.23±3.99 µm (1.48 to 3.98 µm). These morphological features match the description of Meloidogyne incognita (Eisenback et al. 1981). To further confirm the species, we selected three infected plants from each field for molecular identification, the ITS region amplified using the primers 18S/26S (5'-TTGATTACGTCCCTGCCCTTT-3',5'-TTTCACTCGCCGTTACTAAGG-3') (Vrain et al. 1992) . A 729 bp PCR product of ITS region (accession nos. OR463907) was obtained from all infected plants. The amplicons from 18S/26S primer pair were sequenced and the sequences showed 95.29% homology with sequences of M. incognita (accession nos. MT209948.1). Moreover, a 835 bp DNA fragment (accession nos. OR469000) was obtained using the specific primers Mi-F/Mi-R (5'-GTGAGGATTCAGCTCCCCAG-3',5'-ACGAGGAACATACTTCTCCGTCC-3') for M. incognita (Meng et al. 2004), the sequence showed 99.28% homology with sequences of M. incognita (accession nos. ON416569). The morphological features and molecular data confirmed the identification of the root-knot nematode on B. striata Rchb.f. as M. incognita. To confirm the pathogenicity, ten healthy B. striata Rchb.f. seedlings were each inoculated with 500 freshly hatched J2s isolated from field Bletilla striata Rchb.f.. Five healthy seedlings without J2 inoculation were used as controls. At 60 days after inoculation, most of the inoculated plants exhibited similar symptoms to those initially observed by farmers in the field. On average, 1532 J2s were recovered from each inoculated plant, yielding a reproductive factor of 2.1. The gall rating for these inoculated plants was 2. Fuchsin staining revealed the presence of root-knot nematode females within the roots, with an average of 17 females detected per inoculated plant. No symptoms were observed in the control plants. This is the first report of M. incognita infecting B. striata Rchb.f. in China. M. incognita can cause severe infection and damage to some crops, resulting in serious economic losses (Eisenback, 2022). The growers need to take measures to prevent the spread of this nematode.

Persimmon preservation using edible coating of chitosan enriched with ginger oil and visualization of internal structure changes using X-ray computed tomography.

The incorporation of ginger oil (GO) influenced the physical, optical, and structural properties of the chitosan (CH) film including the decreases of moisture content (60.15 %), water solubility (35.37 %) and water vapor permeability (WVP) (32.79 %) and the increases of tensile strength (TS) (125 %), elongation at break (EAB) (2.74 %) and opacity (131.08 %). Antifungal capacity of the CH film was enhanced when GO was added to the film. The CH + GO film showed a less homogeneous surface that the presence of the oil droplets on the film surface. Moreover, the CH and CH + GO coatings reduced weight loss of persimmon by 14.87 %, and 21.13 %, respectively, compared to the control. Moisture content loss of the coated CH- and the coated CH + GO- persimmons was decreased by 1.94 % and 4.92 %, respectively, compared to that of the control persimmon. Furthermore, the CH and CH + GO coatings decreased in color changes, respiration rate, ethylene production, changes in pH and TSS, and remained firmness of persimmon during storage at 25 °C. In addition, X-ray CT images can be used to monitor internal changes and observe the tissue breakdown during storage period. The ΔGS value can be used as a predictor of persimmon internal qualities. Thus, the CH film containing GO can be applied as an active packaging material.

Improvement of cross-linked films based on chitosan/diepoxy-poly (ethylene glycol) incorporating trans-cinnamaldehyde essential oil: Preparation, properties, and application in banana storage.

In this study, development of bioactive coatings containing 1 % (w/v) chitosan (CS), 0.6 % (w/v) diepoxy-polyethylene glycol (PEG), and trans-cinnamaldehyde (CIN) was achieved. The physicochemical and biological properties of the coatings were investigated. The tensile strength, light transmission, water vapor permeability (WVP), and antibacterial properties were enhanced by the incorporation of CIN. The CIN-containing films appeared compact and rough, as observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the quality attributes of the bananas were evaluated at room temperature for 24 days, and the results showed that the CS/PEG/CIN coating delayed the respiration peak, weight loss, sugar content loss, and maintained firmness, color, total soluble solids (TSS), titratable acid (TA), and the appearance of the bananas. Principal component analysis (PCA) revealed that the bioactive coating significantly affected the respiration rate and weight loss of bananas.

Comparative Transcriptome Analysis Reveals the Molecular Mechanism of Bacillus velezensis GJ-7 Assisting Panax notoginseng against Meloidogyne hapla.

The rhizosphere bacteria Bacillus velezensis GJ-7, as a biological control agent (BCA), has significant biological control effects on Meloidogyne hapla, and has strong colonization ability in the root of Panax notoginseng. In this study, we conducted a comparative transcriptome analysis using P. notoginseng plant roots treated with B. velezensis GJ-7 or sterile water alone and in combination with M. hapla inoculation to explore the interactions involving the P. notoginseng plant, B. velezensis GJ-7, and M. hapla. Four treatments from P. notoginseng roots were sequenced, and twelve high-quality total clean bases were obtained, ranging from 3.57 to 4.74 Gb. The Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment showed that numerous DEGs are involved in the phenylpropane biosynthesis pathway and the MAPK signaling pathway in the roots of P. notoginseng with B. velezensis GJ-7 treatments. The analysis results of the two signaling pathways indicated that B. velezensis GJ-7 could enhance the expression of lignin- and camalexin-synthesis-related genes in plant roots to resist M. hapla. In addition, B. velezensis GJ-7 could enhance plant resistance to M. hapla by regulating the expression of resistance-related genes and transcription factors (TFs), including ETR, ERF, ChiB, WRKY22, and PR1. The expression of plant disease resistance genes in the roots of P. notoginseng with different treatments was validated by using real-time quantitative PCR (qRT-PCR), and the results were consistent with transcriptome sequencing. Taken together, this study indicated that B. velezensis GJ-7 can trigger a stronger defense response of P. notoginseng against M. hapla.

Characterization and bio-functional performance of chitosan/poly (vinyl alcohol)/trans-cinnamaldehyde ternary biopolymeric films.

Bioactive films of chitosan (CS)/polyvinyl alcohol (PVA)/trans-cinnamaldehyde (CIN) were prepared by co-blending, and the impact of varying concentrations (0.5, 1.0 and 1.5 %) of CIN on the physicochemical properties of the ternary films was investigated. The ATR/FT-IR analysis revealed that the bioactive film is modulated by Schiff base (C=N) and hydrogen-bond interactions of CS, PVA, and CIN. Inclusion of CIN into the film improved mechanical properties with tensile strength increased from 0.5 % (68.52 MPa) to 1.5 % (76.95 MPa). The presence of CIN within the CS/PVA film also remarkably affected oxygen permeability and improved light transmittance. Additionally, the water barrier and contact angle properties were improved with increasing CIN content. The morphology of the CIN-containing films appeared non-stratified and dense when observed by SEM and AFM. Moreover, spore germination and in vitro assays confirmed strong antifungal activity of the CIN-containing film against P. italicum (~90 %) and B. cinerea (~85 %). The ternary films also exhibited excellent antioxidant activity, as evidenced by DPPH radical scavenging activity (31.43 %) and ferric reducing power (OD700 nm = 0.172) at the highest CIN concentration tested. Thus, this bioactive CIN films are proposed as a versatile packaging material for the food industry.

Curcumin protects against the age-related hearing loss by attenuating apoptosis and senescence via activating Nrf2 signaling in cochlear hair cells.

Age-related hearing loss (ARHL) is a most widespread neurodegenerative disease affecting the elderly population, but effective pharmacological treatments remain limited. Curcumin is a bioactive compound of Curcuma longa with antioxidant properties. Herein, we looked into the effects of curcumin on the H2O2-induced oxidative stress in cochlear hair cells and hearing function in an ARHL animal model (C57BL/6J mice). We found that pretreatment of curcumin could attenuate H2O2-induced apoptosis and cell senescence in auditory hair cells and prevent mitochondrial function dysfunction. More specifically, Western blot and luciferase activity assay showed that curcumin activated the nuclear translocation of Nrf2, which in turn triggered the activation of its downstream target gene Heme Oxygenase1 (HO-1). The enhanced Nrf2 and HO-1 activity by curcumin was blocked by the AKT inhibitor LY294002, indicating the protective effect of curcumin was mainly achieved by activating Nrf2/HO-1 through the AKT pathway. Furthermore, the knockdown of Nrf2 with siRNA diminished the protective effects of Nrf2 against apoptosis and senescence, consolidating the pivotal role of Nrf2 in the protective effect of curcumin on auditory hair cells. More importantly, curcumin (10 mg/kg/d) could attenuate progressive hearing loss in C57BL/6J mice, as evident from the reduced threshold of auditory nerve brainstem response. Administration of curcumin also elevated the expression of Nrf2 and reduced the expression of cleaved-caspase-3, p21, and γ-H2AX in cochlear. This study is the first to demonstrate that curcumin can prevent oxidative stress-induced auditory hair cell degeneration through Nrf2 activation, highlighting its potential therapeutic value in preventing ARHL.

Volatile Organic Compounds of Bacillus velezensis GJ-7 against Meloidogyne hapla through Multiple Prevention and Control Modes.

The Bacillus velezensis GJ-7 strain isolated from the rhizosphere soil of Panax notoginseng showed high nematicidal activity and therefore has been considered a biological control agent that could act against the root-knot nematode Meloidogyne hapla. However, little was known about whether the GJ-7 strain could produce volatile organic compounds (VOCs) that were effective in biocontrol against M. hapla. In this study, we evaluated the nematicidal activity of VOCs produced by the fermentation of GJ-7 in three-compartment Petri dishes. The results revealed that the mortality rates of M. hapla J2s were 85% at 24 h and 97.1% at 48 h after treatment with the VOCs produced during GJ-7 fermentation. Subsequently, the VOCs produced by the GJ-7 strain were identified through solid-phase micro-extraction gas chromatography mass spectrometry (SPME-GC/MS). Six characteristic VOCs from the GJ-7 strain fermentation broth were identified, including 3-methyl-1-butanol, 3-methyl-2-pentanone, 5-methyl-2-hexanone, 2-heptanone, 2,5-dimethylpyrazine, and 6-methyl-2-heptanone. The in vitro experimental results from 24-well culture plates showed that the six volatiles had direct-contact nematicidal activity against M. hapla J2s and inhibition activity against egg hatching. In addition, 3-methyl-1-butanol and 2-heptanone showed significant fumigation effects on M. hapla J2s and eggs. Furthermore, all six of the VOCs repelled M. hapla J2 juveniles in 2% water agar Petri plates. The above data suggested that the VOCs of B. velezensis GJ-7 acted against M. hapla through multiple prevention and control modes (including direct-contact nematicidal activity, fumigant activity, and repellent activity), and therefore could be considered as potential biocontrol agents against root-knot nematodes.

Network pharmacology and experimental evidence reveal the protective mechanism of Yi-Qi Cong-Ming decoction on age-related hearing loss.

CONTEXT: Yi-Qi Cong-Ming (YQCM) decoction has been widely used to prevent age-related hearing loss (ARHL), the most prevalent neurodegenerative disease in the elderly. OBJECTIVE: To explore the mechanism of YQCM decoction in the treatment of ARHL. MATERIALS AND METHODS: The chemical constituents of YQCM were screened from the Traditional Chinese Medicine Systems Pharmacology Database. Potential targets of YQCM against ARHL were predicted by DrugBank, GeneCards, and OMIM database. Protein-protein network and enrichment analysis were used for exploring possible molecular mechanisms. Molecular docking and an in vitro model of ARHL by exposing auditory cells with 100 µM H2O2 for 3 h were applied. Cell viability and mitochondrial membrane potential (ΔΨM) were detected by CCK-8 and high-content analysis. γH2AX and cleaved caspase-3 were detected by Western blot. RESULTS: The main compounds have good affinities with hub targets, especially AKT1, PTGS2, and CASP3. GO and KEGG analysis showed that the main biological process and key targets were related to negative regulation of the apoptotic process. H2O2 treatment could reduce the cell viability by 68% and impaired ΔΨM, while 90 µg/mL YQCM pre-treatment could restore the cell viability by 97.45% and increase ΔΨM (2-fold higher). YQCM pre-treatment also reduced γH2AX and cleaved caspase-3 protein levels. CONCLUSIONS: Our study suggested that YQCM prevents ARHL by modulating the apoptosis process in auditory hair cells. Moreover, this study proved that bioinformatics analysis combined with molecular docking and cell model is a promising method to explore other possible pharmacological interventions of ARHL.

Prediction of the Molecular Mechanisms Underlying Erlong Zuoci Treatment of Age-Related Hearing Loss via Network Pharmacology-Based Analyses Combined with Experimental Validation.

Background: The traditional Chinese medicine formula ErLong ZuoCi (ELZC) has been extensively used to treat age-related hearing loss (ARHL) in clinical practice in China for centuries. However, the underlying molecular mechanisms are still poorly understood. Objective: Combine network pharmacology with experimental validation to explore the potential molecular mechanisms underlying ELZC with a systematic viewpoint. Methods: The chemical components of ELZC were collected from the Traditional Chinese Medicine System Pharmacology database, and their possible target proteins were predicted using the SwissTargetPrediction database. The putative ARHL-related target proteins were identified from the database: GeneCards and OMIM. We constructed the drug-target network as well as drug-disease specific protein-protein interaction networks and performed clustering and topological property analyses. Functional annotation and signaling pathways were performed by gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Finally, in vitro experiments were also performed to validate ELZC's key target proteins and treatment effects on ARHL. Results: In total, 63 chemical compounds from ELZC and 365 putative ARHL-related targets were identified, and 1860 ARHL-related targets were collected from the OMIM and GeneCards. A total of 145 shared targets of ELZC and ARHL were acquired by Venn diagram analysis. Functional enrichment analysis suggested that ELZC might exert its pharmacological effects in multiple biological processes, such as cell proliferation, apoptosis, inflammatory response, and synaptic connections, and the potential targets might be associated with AKT, ERK, and STAT3, as well as other proteins. In vitro experiments revealed that ELZC pretreatment could decrease senescence-associated ß-galactosidase activity in hydrogen peroxide-induced auditory hair cells, eliminate DNA damage, and reduce cellular senescence protein p21 and p53. Finally, Western blot analysis confirmed that ELZC could upregulate the predicted target ERK phosphorylation. Conclusion: We provide an integrative network pharmacology approach, in combination with in vitro experiments to explore the underlying molecular mechanisms governing ELZC treatment of ARHL. The protective effects of ELZC against ARHL were predicted to be associated with cellular senescence, inflammatory response, and synaptic connections which might be linked to various pathways such as JNK/STAT3 and ERK cascade signaling pathways. As a prosperous possibility, our experimental data suggest phosphorylation ERK is essential for ELZC to prevent degeneration of cochlear.

Synthesis of nano-octahedral MgO via a solvothermal-solid-decomposition method for the removal of methyl orange from aqueous solutions.

Nano magnesium oxide has wide applications, and MgO with (111) facets has wider potential applications than MgO with (100) facets (e.g., in catalysis and adsorption). However, nano MgO with (111) polar faces has not been studied throughly, so the preparation of nano-octahedral MgO (N-O-MgO) with eight exposed (111) facets remains a great challenge. Herein, we successfully synthesised N-O-MgO via an effective solvothermal-solid-decomposition method and studied its adsorption performance. The obtained N-O-MgO showed excellent performance (229.36 mg g-1) for methyl orange (MO). The adsorption follows the pseudo-second-order kinetic equation and the Langmuir isotherm model. The dimensionless parameter R L (0.042) and Gibbs free energy ΔG (-6.538 kJ mol-1) revealed that the adsorption of MO on N-O-MgO was a spontaneous and feasible process. The adsorption of MO and methyl blue (MB) on N-O-MgO were studied to determine the adsorption sites. Based on these experiments and analysis, it was determined that the adsorption sites were magnesium ions and the adsorption mechanism was proposed to describe the adsorption process.