19 research outputs found

    A Plant-Derived Alkanol Induces Teliospore Germination in Sporisorium scitamineum

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    Sugarcane smut caused by the basidiomycetes fungus Sporisorium scitamineum is a devastating disease for the sugarcane industry worldwide. As the initial step, the smut teliospores germinate on sugarcane buds, and subsequently, the mycelium infects the bud tissues. However, chemical signals that induce spore germination are still unknown. By comparison of the behavior of the teliospores on the buds of both resistant and susceptible varieties, we found that spore germination rates were significantly lower on the buds of resistant cultivars ZZ1, ZZ6, and ZZ9 than on the susceptible varieties GT42 and ROC22. It was found that the levels of hexacosanol and octacosanol were higher on the buds of smut-susceptible varieties than on the smut-resistant varieties. These observations were extended to the smut-resistant and smut-susceptible sub-genetic populations derived from the cross of ROC25 and YZ89-7. In artificial surface assays, we found that hexacosanol and octacosanol promoted smut teliospore germination. Transcriptome analysis of smut teliospores under the induction by octacosanol revealed that genes in the MAPK signaling pathway and fatty acid metabolism were significantly differentially expressed. Overall, our results provide evidence that alkanol plays important roles in smut teliospore germination and thus could be used as a potential marker for smut resistance in sugarcane breeding programs

    Andreev reflection and 0-

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    We investigate the Andreev reflection and 0-¤Ç transition in the graphene-based antiferromagnetic superconducting junctions on the SiC substrate, respectively. The differential conductance of Andreev reflection is reduced in the presence of a gap induced by the antiferromagnet or the substrate. Interestingly, although the gap induced by the antiferromagnet is the same to the one induced by the substrate, their differential conductances of the Andreev reflection are absolutely different, which can be used to detect antiferromagnetism in experiment. Although the interaction between the antiferromagnet and the substrate cannot show special differential conductance, their interaction can bring the 0-¤Ç transition. This breaks up the conventional wisdom that the antiferromagnetism-induced 0-¤Ç transition shows a rigorous atomic-scale dependence on the interlayer thickness. Furthermore, compared with the conventional atomic-scale dependent 0-¤Ç transition, our finding can be realized more easily in the experiment

    Induction of Diverse Bioactive Secondary Metabolites from the Mangrove Endophytic Fungus Trichoderma sp. (Strain 307) by Co-Cultivation with Acinetobacter johnsonii (Strain B2)

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    Two new sesquiterpenes, microsphaeropsisin B (1) and C (2), and two new de-O-methyllasiodiplodins, (3R, 7R)-7-hydroxy-de-O-methyllasiodiplodin (4) and (3R)-5-oxo-de-O-methyllasiodiplodin (5), together with one new natural product (6) and twelve known compounds (3, 7ÔÇô17), were isolated from the co-cultivation of mangrove endophytic fungus Trichoderma sp. 307 and aquatic pathogenic bacterium Acinetobacter johnsonii B2. Their structures, including absolute configurations, were elucidated by extensive analysis of spectroscopic data, electronic circular dichroism, Mo2(AcO)4-induced circular dichroism, and comparison with reported data. All of the isolated compounds were tested for their ╬▒-glucosidase inhibitory activity and cytotoxicity. New compounds 4 and 5 exhibited potent ╬▒-glucosidase inhibitory activity with IC50 values of 25.8 and 54.6 ┬ÁM, respectively, which were more potent than the positive control (acarbose, IC50 = 703.8 ┬ÁM). The good results of the tested bioactivity allowed us to explore ╬▒-glucosidase inhibitors in lasiodiplodins

    Ultrasensitive Photoelectrochemical Biosensing of Cell Surface NÔÇĹGlycan Expression Based on the Enhancement of Nanogold-Assembled Mesoporous Silica Amplified by Graphene Quantum Dots and Hybridization Chain Reaction

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    An ultrasensitive photoelectrochemical (PEC) biosensor for N-glycan expression based on the enhancement of nanogold-assembled mesoporous silica nanoparticles (GMSNs) was fabricated, which also combined with multibranched hybridization chain reaction (mHCR) and graphene quantum dots (GQDs). In this work, the localized surface plasmon resonance, mHCR and GQDs-induced signal amplification strategies were integrated exquisitely and applied sufficiently. In the fabrication, after porous ZnO spheres immobilized on the Au nanorod-modified paper working electrode were sensitized by CdTe QDs, the GMSNs were assembled on the CdTe QDs. Then the photocurrent efficiency was improved by the sensitization of the CdTe QDs and the localized surface plasmon resonance of GMSNs. Successively, the products of mHCR with multiple biotins for multiple horseradish peroxidase binding and multiple branched arms for capturing the target cells were attached on the as-prepared electrode. The chemiluminescent (CL) emission with the aid of horseradish peroxidase served as an inner light source to excite photoactive materials for simplifying the instrument. Furthermore, the aptamer could capture the cancer cells by its highly efficient cell recognition ability, which avoided the conventional routing cell counting procedures. Meanwhile, the GQDs served as the signal amplication strategy, which was exerted in the process of N-glycan evaluation because the competitive absorption of exciting light and consumption of H<sub>2</sub>O<sub>2</sub> served as the electron donor of the PEC system and the oxidant of the luminol-based CL system. This judiciously engineered biosensor offered a promising platform for the exploration of N-glycan-based physiological processes

    Effects of 60 days of 6° head-down bed rest on the composition and function of the human gut microbiota

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    Summary: Spaceflight is rigorous and dangerous environment which can negatively affect astronautsÔÇÖ health and the entire mission. The 60┬ádays of 6┬░ head-down bed rest (HDBR) experiment provided us with an opportunity to trace the change of gut microbiota under simulated microgravity. The gut microbiota of volunteers was analyzed and characterized by 16S rRNA gene sequencing and metagenomic sequencing. Our results showed that the composition and function of the volunteersÔÇÖ gut microbiota were markedly was affected by 60┬ádays of 6┬░ HDBR. We further confirmed the species and diversity fluctuations. Resistance and virulence genes in the gut microbiota were also affected by 60┬ádays of 6┬░ HDBR, but the species attributions remained stable. The human gut microbiota affected by 60┬ádays of 6┬░ HDBR which was partially consistent with the effect of spaceflight, this implied that HDBR was a simulation of how spaceflight affects the human gut microbiota