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Zizania latifolia, which belongs to the tribe Oryzea, has been widely grown over thousands of years as an aquatic vegetable in China. In the autumn of 2019, the disease harmful to the leaf sheaths of Z. latifolia was found in Jinhua City and Lishui City, Zhejiang Province. The disease caused brown oval-shaped spots (3~5 cm long, 0.5~1 cm wide) on leaf sheaths (Figure 1A). The infected plants produced non-commercial Jiaobai. The surface of the Jiaobai was pale yellow instead of white, and the length of the Jiaobai was 25% shorter than the uninfected plants. To 2022, the disease has been found in most planting areas of Z. latifolia in Zhejiang, Jiangsu, Fujian, Jiangxi and Anhui provinces in China. About 20%~50% incidence of the disease in these main production areas has seriously threatened the yield and quality of Jiaobai. To identify the causal agent, diseased leaf sheaths were collected. Symptomatic leaf sheath tissue was sterilized with 75% alcohol for 30 sec, and then washed three times with sterile distilled water for 1 min. A total of 37 strains were isolated on potato dextrose agar (PDA). We selected 10 strains for further morphological identification. An abundant mass of aerial mycelia was formed in 8 days (Figure 1B). The mycelium is transparent, septate and smooth. Conidia is fusiform, straight or curved, 0~3 septa, hyaline, tapering and rounding at the apex (Figure 1C and 1D). Strain XYQ3 was obtained through multi-generation culture. To further identify the pathogen of this fungus, genomic DNA was extracted and internal transcribed spacer (ITS), large subunit rDNA (LSU), ß-tubulin (BTUB) and DNA-directed RNA polymerase II subunit (RPB2) of strain XYQ3 were amplified. These sequences were obtained and submitted to GenBank (accession numbers MT605000, OP585914, MZ619085, MZ619084, respectively). After alignment analysis of sequencing data, we found that the ITS sequence indicated 100% identity with M. seminicola (GenBank acc no. KP859007). The LSU sequence showed 100% identity with M. seminicola (GenBank acc no. KP858943). The BTUB sequence showed 99.47% identity with M. seminicola (GenBank acc no. KP859070). The RPB2 sequence has higher identity with M. seminicola, reaching 99.76% with 4 sequences (GenBank acc nos. KP859140, KP859116, KP859134 and KP859130). Strain XYQ3 and a total of 16 other Microdochium isolates were selected for phylogenetic analysis using the ITS, LSU, BTUB and RPB2 sequences (Figure 2). Phylogenetic tree analysis revealed that strain XYQ3 was clustered with the M. seminicola clade, including M. seminicola strains MFG 60131, MFG 60132, CBS 122706 and KAS 1527. Therefore, this fungus was identified as M. seminicola based on morphological observation, multiple sequences alignment analysis and phylogenetic analysis. Strain XYQ3 was used in pathogenicity tests. According to Koch's postulates, 10 fresh leaf sheaths and leaves of host plants were inoculated by spraying conidial suspension at the concentration of 1×106 conidia/mL. Sterile water was sprayed as negative control. Inoculated plants were cultured under 25â light for 10 h, darkness for 14 h, covered with plastic film to maintain high humidity above 65%, and observed daily for disease development. After 6 d, symptoms similar to those observed in the field (Figure 1E and 1F). The pathogen of this fungus was re-isolated from the symptomatic inoculated leaf sheath and re-identified as strain XYQ3. Many Microdochium species are important pathogens of Poaceae (Liang et al., 2019). M. seminicola is classified as a new species in the Xylariales family by the report of Hernández-Restrepo (Hernandez-Restrepo et al., 2016) and was only found in wheat, oats and barley so far (Gagkaeva et al., 2020; Gavrilova et al., 2020). To the best of our knowledge, this fungus is the first report in the disease of Z. latifolia. As this disease is prevalent in main planting areas of Z. latifolia and has seriously threatened the production of Jiaobai, it is very important to isolate and identify the pathogen for the subsequent drug screening and control.
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BACKGROUND: Ustilago esculenta, a typical dimorphic fungus could infect Zizania latifolia and induce host stem swollen to form an edible vegetable called Jiaobai in China. The strains differentiation especially in the mating ability and pathogenicity is closely related to different phenotypes of Jiaobai formed in the fields. Dimorphic switching, a tightly regulated processes, is essential for the pathogenetic development of dimorphic fungi. In responses to environment cues, dimorphic switching can be activated through two conserved cell signaling pathways-PKA and MAPK pathways. Previous study indicated that exogenous arginine could induce hyphal formation in several dimorphic fungi through hydrolysis by arginase, but inhibit the dimorphic transition of U. esculenta. We conducted this study to reveal the function of arginine on dimorphic transition of U. esculenta. RESULTS: In this study, we found that arginine, but not its anabolites, could slow down the dimorphic transition of U. esculenta proportionally to the concentration of arginine. Besides, UeArginase, predicated coding arginase in U. esculenta was cloned and characterized. UeArginase mutants could actually increase the content of endogenous arginine, and slow down the dimorphic transition on either nutritious rich or poor medium. Either adding exogenous arginine or UeArginase deletion lead to down regulated expressions of UePkaC, UePrf1, mfa1.2, mfa2.1, pra1 and pra2, along with an increased content of arginine during mating process. CONCLUSION: Results of this study indicated a direct role of arginine itself on the inhibition of dimorphic transition of U. esculenta, independent of its hydrolysis by UeArginase.
Assuntos
Arginase/metabolismo , Arginina/metabolismo , Clonagem Molecular , Proteínas Fúngicas/metabolismo , Ustilago/enzimologia , Ustilago/crescimento & desenvolvimento , Arginase/genética , Proteínas Fúngicas/genética , Hifas/enzimologia , Hifas/genética , Hifas/crescimento & desenvolvimento , Hifas/metabolismo , Filogenia , Doenças das Plantas/microbiologia , Poaceae/microbiologia , Ustilago/genética , Ustilago/metabolismoRESUMO
Rice (Oryza sativa) has the potential to undergo rapid internodal elongation which determines plant height. Gibberellin is involved in internode elongation. Leucine-rich repeat receptor-like kinases (LRR-RLKs) are the largest subfamily of transmembrane receptor-like kinases in plants. LRR-RLKs play important functions in mediating a variety of cellular processes and regulating responses to environmental signals. LRK1, a PSK receptor homolog, is a member of the LRR-RLK family. In the present study, differences in ectopic expression of LRK1 were consistent with extent of rice internode elongation. Analyses of gene expression demonstrated that LRK1 restricts gibberellin biosynthesis during the internode elongation process by down-regulation of the gibberellin biosynthetic gene coding for ent-kaurene oxidase.
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Sistema Enzimático do Citocromo P-450/genética , Oryza/crescimento & desenvolvimento , Oryza/genética , Proteínas de Plantas/genética , Proteínas Quinases/genética , Sistema Enzimático do Citocromo P-450/análise , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica de Plantas , Giberelinas/biossíntese , Giberelinas/genética , Giberelinas/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Oryza/metabolismo , Fenótipo , Proteínas de Plantas/biossíntese , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Quinases/biossíntese , Proteínas Quinases/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Transdução de SinaisRESUMO
Objective: To promote the development and therapeutic application of new medications, it is crucial to conduct a thorough investigation into the mechanism by which the traditional Chinese herb pair of Haizao-Kunbu (HK) treats Graves' disease (GD). Materials and methods: Chemical ingredients of HK, putative target genes, and GD-associated genes were retrieved from online public databases. Using Cytoscape 3.9.1, a compound-gene target network was established to explore the association between prosperous ingredients and targets. STRING, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes pathway analyses visualized core targets and disease pathways. Additionally, we conducted a refined analysis of the binding interactions between active ingredients and their respective targets. To visualize these findings, we employed precise molecular docking techniques. Furthermore, we carried out molecular dynamics simulations to gain insights into the formation of more tightly bound complexes. Results: We found that there were nine key active ingredients in HK, which mainly acted on 21 targets. These targets primarily regulated several biological processes such as cell population proliferation, protein phosphorylation, and regulation of kinase activity, and acted on PI3K-AKT and MAPK pathways to treat GD. Analysis of the molecular interaction simulation under computer technology revealed that the key targets exhibited strong binding activity to active ingredients, and Fucosterol-AKT1 and Isofucosterol-AKT1 complexes were highly stable in humans. Conclusion: This study demonstrates that HK exerts therapeutic effects on GD in a multi-component, multi-target, and multi-pathway manner by regulating cell proliferation, differentiation, inflammation, and immunomodulatory-related targets. This study provides a theoretical foundation for further investigation into GD.
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Doença de Graves , Simulação de Dinâmica Molecular , Humanos , Simulação de Acoplamento Molecular , Farmacologia em Rede , Fosfatidilinositol 3-Quinases , Doença de Graves/tratamento farmacológico , Doença de Graves/genéticaRESUMO
Steam reforming for hydrogen production is one of the important research directions for clean energy. NiTiO3 catalysts with a hierarchical porous structure are prepared and applied to methanol steam reforming for hydrogen production. The results show that the optimum catalyst (10% Ni-Ti-Ox) not only has a hierarchical porous structure, but it also involves the coexistence of NiTiO3, anatase TiO2 and rutile TiO2. The formation of NiTiO3 is beneficial to the adsorption and activation of methanol molecules on the surface of the Ni-Ti-Ox catalyst, and the main intermediate species of the methanol molecular reaction are hydroxyl groups, methoxy species and formic acid species. Furthermore, the methanol steam reforming reaction is mainly dominated by methanol decomposition at low temperature (350-500 °C), while it is mainly dominated by methanol and water molecular reactions at high temperature (500-600 °C).
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Smut fungi display a uniform life cycle including two phases: a saprophytic phase in vitro and a parasitic phase in host plants. Several apathogenic smut fungi are found, lacking suitable hosts in their habitat. Interestingly, MT-type Ustilago esculenta was found to maintain a parasitic life, lacking the saprophytic phase. Its long period of asexual proliferation in plant tissue results in severe defects in certain functions. In this study, the growth dynamics of U. esculenta in plant tissues were carefully observed. The mycelia of T- and MT-type U. esculenta exhibit rapid growth after karyogamy and aggregate between cells. While T-type U. esculenta successfully forms teliospores after aggregation, the aggregated mycelia of MT-type U. esculenta gradually disappeared after a short period of massive proliferation. It may be resulted by the lack of nutrition such as glucose and sucrose. After overwintering, infected Zizania latifolia plants no longer contained diploid mycelia resulting from karyogamy. This indicated that diploid mycelia failed to survive in plant tissues. It seems that diploid mycelium only serves to generate teliospores. Notably, MT-type U. esculenta keeps the normal function of karyogamy, though it is not necessary for its asexual life in plant tissue. Further investigations are required to uncover the underlying mechanism, which would improve our understanding of the life cycle of smut fungi and help the breeding of Z. latifolia.
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The Zizania latifolia is usually infected by the obligate parasitic fungus Ustilago esculenta to form an edible fleshy stem which is an aquatic vegetable called Jiaobai in China. The infection by the teliospore (T) strain of U. esculenta induces Z. latifolia forming gray fleshy stems, while the mycelia-teliospore (MT) strain of U. esculenta induces white fleshy stems which are more suitable for edibility than gray fleshy stems. The mechanism of this phenomenon is still largely unknown. One of the possible causes is the diversity of endophytic microbial communities between these two fleshy stems. Therefore, we utilized fungal ITS1 and bacterial 16S rDNA amplicon sequencing to investigate the diversity of endophytic microbial communities in the two different fleshy stems of Z. latifolia. The results revealed that the α diversity and richness of endophytic fungi in white Z. latifolia were significantly greater than in gray Z. latifolia. The dominant fungal genus in both fleshy stems was U. esculenta, which accounted for over 90% of the endophytic fungi. The community composition of endophytic fungi in gray and white Z. latifolia was different except for U. esculenta, and a negative correlation was observed between U. esculenta and other endophytic fungi. In addition, the dominant bacterial genus in gray Z. latifolia was Alcaligenaceae which is also negatively correlated with other bacterium communities. Additionally, the co-occurrence network of white Z. latifolia was found to have a stronger scale, connectivity, and complexity compared to that of gray Z. latifolia. And the detected beneficial bacteria and pathogens in the stems of Z. latifolia potentially compete for resources. Furthermore, the function of endophytic bacteria is more abundant than endophytic fungi in Z. latifolia. This research investigated the correlation between the development of Z. latifolia fleshy stems and endophytic microbial communities. Our findings indicate that the composition of endophytic microbial communities is closely related to the type of Z. latifolia fleshy stems. This research also suggests the potential utilization of specific microbial communities to enhance the growth and development of Z. latifolia, thereby contributing to the breeding of Z. latifolia.
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Linear-conjugated polymers (LCPs) are excellent semiconductor photocatalysts. However, its inherent amorphous structures and simple electron transport channels restrict efficient photoexcited charge separation and transfer. Herein, "2D conjugated engineering" is employed to design high-crystalline polymer photocatalysts with multichannel charge transport by introducing alkoxyphenyl sidechains. The electronic state structure and electron transport pathways of the LCPs are investigated using experimental and theoretical calculations. Consequently, the 2D BâN-containing polymers (2DPBN) exhibit excellent photoelectric characteristics, which enable the efficient separation of electron-hole and rapidly transfer photogenerated carriers to the catalyst surface for efficient catalytic reactions. Significantly, the further hydrogen evolution of 2DPBN-4F heterostructures can be achieved by increasing the fluorine content of the backbones. This study highlights that the rational design of LCP photocatalysts is an effective strategy to spur further interest in photofunctional polymer material applications.
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Zizania latifolia (Z. latifolia) is a popular aquatic vegetable with various nutrients in south China, but little is known about its cultivars and growing seasons in terms of the nutritional components. This work aims to characterize the nutrients of five Z. latifolia cultivars in different growing seasons. The results showed that Z. latifolia samples differed in terms of chemical parameters, which were significantly affected by variety, growing season, and their interaction. Zhejiao No. 8, harvested in the autumn, stood out with the highest levels of vitamin C. Tangxiajiao and Zhejiao No. 1 contained the highest values of total soluble solids, reducing sugar, soluble proteins, and amino acids. Significant differences were observed between the autumn Z. latifolia and spring samples; the former were of higher quality than the latter based on hierarchical clustering analysis and principal component analysis. Moreover, total amino acids (TAA) and glutamic acid (GLU) were selected as the key indicators for Z. latifolia comprehensive quality by multiple linear regression analysis. This study provides essential information on Z. latifolia quality characteristics corresponding to cultivars and growing seasons, which lays the foundation for promoting the quality improvement of Z. latifolia scientifically.
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Physical aging is a long-lasting research hot spot in the glass community, yet its long-term effects remain unclear because of the limited experimental time. In this study, we discover the extraordinary aging effects in five typical lunar glassy particles with diameters ranging from about 20 to 53 micrometers selected from Chang'e-5 lunar regolith. It is found that geological time scales' aging can lead to unusually huge modulus enhancements larger than 73.5% while much weaker effects on hardness (i.e., varies decoupling evolutions of Young's modulus and hardness during aging) in these lunar glassy samples. Such extraordinary aging effects are primarily attributed to the natural selected complex glassy compositions and structures, consistent with high entropy and minor element doping criteria, prevailing under the special lunar conditions and the extensive aging time for the lunar glasses. This study offers valuable insights for developing high-performance and stable glassy materials for radiation protection and advanced space explorations.
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Lunar glasses with different origins act as snapshots of their formation processes, providing a rich archive of the Moon's formation and evolution. Here, we reveal diverse glasses from Chang'E-5 (CE-5) lunar regolith, and clarify their physical origins of liquid quenching, vapor deposition and irradiation damage respectively. The series of quenched glasses, including rotation-featured particles, vesicular agglutinates and adhered melts, record multiple-scale impact events. Abundant micro-impact products, like micron- to nano-scale glass droplets or craters, highlight that the regolith is heavily reworked by frequent micrometeorite bombardment. Distinct from Apollo samples, the indigenous ultra-elongated glass fibers drawn from viscous melts and the widespread ultra-thin deposited amorphous rims without nanophase iron particles both indicate a relatively gentle impact environment at the CE-5 landing site. The clarification of multitype CE-5 glasses also provides a catalogue of diverse lunar glasses, meaning that more of the Moon's mysteries, recorded in glasses, could be deciphered in future.
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Forty-five years after the Apollo and Luna missions returned lunar samples, China's Chang'E-5 (CE-5) mission collected new samples from the mid-latitude region in the northeastern Oceanus Procellarum of the Moon. Our study shows that 95% of CE-5 lunar soil sizes are found to be within the range of 1.40-9.35 µm, while 95% of the soils by mass are within the size range of 4.84-432.27 µm. The bulk density, true density and specific surface area of CE-5 soils are 1.2387 g/cm3, 3.1952 g/cm3 and 0.56 m2/g, respectively. Fragments from the CE-5 regolith are classified into igneous clasts (mostly basalt), agglutinate and glass. A few breccias were also found. The minerals and compositions of CE-5 soils are consistent with mare basalts and can be classified as low-Ti/low-Al/low-K type with lower rare-earth-element contents than materials rich in potassium, rare earth element and phosphorus. CE-5 soils have high FeO and low Mg index, which could represent a new class of basalt.
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In rice (Oryza sativa L.), the number of panicles, spikelets per panicle and grain weight are important components of grain yield. These characteristics are controlled by quantitative trait loci (QTLs) and are derived from variation inherent in crops. As a result of the complex genetic basis of these traits, only a few genes involved in their control have been cloned and characterized. We have previously map-cloned a gene cluster including eight leucine-rich repeat receptor-like kinase (LRK) genes in Dongxiang wild rice (Oryza rufipogon Griff.), which increased the grain yield by 16%. In the present study, we characterized the LRK1 gene, which was contained in the donor parent (Dongxiang wild rice) genome and absent from the recurrent parent genome (Guichao2, Oryza sativa L. ssp. indica). Our data showed that rice LRK1 is a plasma membrane protein expressed constitutively in leaves, young panicles, roots and culms. The over-expression of rice LRK1 results in increased panicles, spikelets per panicle, weight per grain and enhanced cellular proliferation, leading to a 27.09% increase in total grain yield per plant. The increased number of panicles and spikelets per panicle are associated with increased branch number. Our data suggest that rice LRK1 regulates rice branch number by enhancing cellular proliferation. The functional characterization of rice LRK1 facilitates an understanding of the mechanisms involved in cereal crop yield, and may have utility in improving grain yield in cereal crops.