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1.
Stem Cell Res ; 77: 103398, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38552354

RESUMO

Genetic polymorphism of apolipoprotein E (APOE) confers differential susceptibility to Alzheimer's disease (AD), and APOE ɛ4 variants is the most powerful risk factor for this disease. Here, we report the generation of a human induced pluripotent stem cell (iPSC) line carrying the APOE ɛ4/ɛ4 genotype from peripheral blood mononuclear cells (PBMCs) isolated from a male with a family history of AD utilizing non-integrative Sendai virus vector. The iPSC maintains their original genotype, highly express endogenous pluripotency markers, displays a normal karyotype, and retains the ability to differentiate into cells representative of the three germ layers.

2.
Colloids Surf B Biointerfaces ; 237: 113867, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38522284

RESUMO

In this study, hydrogel beads [SPI/HP-Fe (II)] were prepared by cross-linking soybean isolate protein (SPI) and hawthorn pectin (HP) with ferrous ions as a backbone, and the effects of ultrasound and Fe2+ concentration on the mechanical properties and the degree of cross-linking of internal molecules were investigated. The results of textural properties and water-holding capacity showed that moderate ultrasonic power and Fe2+ concentration significantly improved the stability and water-holding capacity of the hydrogel beads and enhanced the intermolecular interactions in the system. Scanning electron microscopy (SEM) confirmed that the hydrogel beads with 60% ultrasonic power and 8% Fe2+ concentration had a denser network. X-ray photoelectron spectroscopy (XPS) and atomic absorption experiments demonstrated that ferrous ions were successfully loaded into the hydrogel beads with an encapsulation efficiency of 82.5%. In addition, in vitro, simulated digestion experiments were performed to understand how the encapsulated Fe2+ is released from the hydrogel beads, absorbed, and utilized in the gastrointestinal environment. The success of the experiments demonstrated that the hydrogel beads were able to withstand harsh environments, ensuring the bioactivity of Fe2+ and improving its bioavailability. In conclusion, a novel and efficient ferrous ion delivery system was developed using SPI and HP, demonstrating the potential application of SPI/HP-Fe (II) hydrogel beads as an iron supplement to overcome the inefficiency of intake of conventional iron supplements.


Assuntos
Crataegus , Hidrogéis , Hidrogéis/química , Pectinas/química , Proteínas de Soja/química , Soja , Ferro , Água , Íons
3.
J Alzheimers Dis Rep ; 8(1): 257-266, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38405340

RESUMO

Background: Previous observational research has indicated a correlation between ferritin levels and neuropsychiatric disorders, although the causal relationship remains uncertain. Objective: The objective of this study was to investigate the potential causal link between plasma ferritin levels and neuropsychiatric disorders. Methods: A two-sample Mendelian randomization (MR) study was conducted, wherein genetic instruments associated with ferritin were obtained from a previously published genome-wide association study (GWAS). Summary statistics pertaining to neuropsychiatric disorders were derived from five distinct GWAS datasets. The primary MR analysis employed the inverse variance weighted (IVW) method and was corroborated by additional methods including MR-Egger, weighted median, simple mode, and weighted mode. Sensitivity analyses were employed to identify potential pleiotropy and heterogeneity in the results. Results: The fixed effects IVW method revealed a statistically significant causal relationship between plasma ferritin level and the occurrence of Alzheimer's disease (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.00-1.12, p = 0.037), as well as Parkinson's disease (OR = 1.06, 95% CI: 1.00-1.13, p = 0.041). Various sensitivity analyses were conducted, which demonstrated no substantial heterogeneity or pleiotropy. Conversely, no compelling evidence was found to support a causal association between ferritin and amyotrophic lateral sclerosis, schizophrenia, or major depressive disorder. Conclusions: This MR study provides evidence at the genetic level for a causal relationship between plasma ferritin and an increased risk of Alzheimer's disease and Parkinson's disease. The exact genetic mechanisms underlying this connection necessitate further investigation.

4.
Mol Plant Pathol ; 25(2): e13429, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38353606

RESUMO

Ustilaginoidea virens is the causal agent of rice false smut, which has recently become one of the most important rice diseases worldwide. Ustilaginoidins, a major type of mycotoxins produced in false smut balls, greatly deteriorates grain quality. Histone acetylation and deacetylation are involved in regulating secondary metabolism in fungi. However, little is yet known on the functions of histone deacetylases (HDACs) in virulence and mycotoxin biosynthesis in U. virens. Here, we characterized the functions of the HDAC UvHOS3 in U. virens. The ΔUvhos3 deletion mutant exhibited the phenotypes of retarded growth, increased mycelial branches and reduced conidiation and virulence. The ΔUvhos3 mutants were more sensitive to sorbitol, sodium dodecyl sulphate and oxidative stress/H2 O2 . ΔUvhos3 generated significantly more ustilaginoidins. RNA-Seq and metabolomics analyses also revealed that UvHOS3 is a key negative player in regulating secondary metabolism, especially mycotoxin biosynthesis. Notably, UvHOS3 mediates deacetylation of H3 and H4 at H3K9, H3K18, H3K27 and H4K8 residues. Chromatin immunoprecipitation assays indicated that UvHOS3 regulates mycotoxin biosynthesis, particularly for ustilaginoidin and sorbicillinoid production, by modulating the acetylation level of H3K18. Collectively, this study deepens the understanding of molecular mechanisms of the HDAC UvHOS3 in regulating virulence and mycotoxin biosynthesis in phytopathogenic fungi.


Assuntos
Histonas , Hypocreales , Micotoxinas , Virulência , Metabolismo Secundário
5.
Plant Cell ; 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38299379

RESUMO

The flower-infecting fungus Ustilaginoidea virens causes rice false smut, which is a severe emerging disease threatening rice (Oryza sativa) production worldwide. False smut not only reduces yield, but more importantly produces toxins on grains, posing a great threat to food safety. U. virens invades spikelets via the gap between the two bracts (lemma and palea) enclosing the floret and specifically infects the stamen and pistil. Molecular mechanisms for the U. virens-rice interaction are largely unknown. Here, we demonstrate that rice flowers predominantly employ chitin-triggered immunity against U. virens in the lemma and palea, rather than in the stamen and pistil. We identify a crucial U. virens virulence factor, named UvGH18.1, which carries glycoside hydrolase activity. Mechanistically, UvGH18.1 functions by binding to and hydrolyzing immune elicitor chitin and interacting with the chitin receptor CHITIN ELICITOR BINDING PROTEIN (OsCEBiP) and co-receptor CHITIN ELICITOR RECEPTOR KINASE1 (OsCERK1) to impair their chitin-induced dimerization, suppressing host immunity exerted at the lemma and palea for gaining access to the stamen and pistil. Conversely, pretreatment on spikelets with chitin induces a defense response in the lemma and palea, promoting resistance against U. virens. Collectively, our data uncover a mechanism for a U. virens virulence factor and the critical location of the host-pathogen interaction in flowers and provide a potential strategy to control rice false smut disease.

6.
Plant Dis ; 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38240714

RESUMO

Northern corn leaf blight (NCLB), caused by Exserohilum turcicum, is one of the most devastating foliar diseases of maize. Rapid and accurate diagnosis for this disease is urgently needed but still limited. Here, we establish a field-deployable diagnostic method to detect E. turcicum based on loop-mediated isothermal amplification (LAMP) assays. A software application called K-mer Elimination by Cross-reference (KEC) was utilized to search for the specific sequences belonging to E. turcicum by comparing the whole genome sequence between E. turcicum and other known maize pathogens. Five LAMP primer sets were designed based on specific and single-copy fragments of E. turcicum. Post-LAMP analyses indicated that only the primer set, Et9468_set1, was the most suitable, producing a ladder-like amplification pattern in the agarose gel electrophoresis and a strong fluorescence signal in the presence of SYBR Green I. The LAMP assay using Et9468_set1 primers demonstrated a high level of specificity in distinguishing E. turcicum from six other common fungal pathogens of maize, as well as 12 more fungal and oomycete strains including the epiphytic fungi from maize leaves and other crop pathogens. Moreover, it exhibited remarkable sensitivity by detecting 5 copies per reaction which was approximately 104 times more sensitive compared to conventional PCR. The LAMP assay successfully detected E. turcicum in field maize leaves without DNA extraction, demonstrating its suitability for rapid on-spot detection of NCLB. Our study provides a direct LAMP diagnostic method to detect E. turcicum, which enables on-site pathogen detection in the field and the development of preventive strategies for NCLB management.

7.
Plant Cell ; 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37831412

RESUMO

Plant immunity is fine-tuned to balance growth and defense. However, little is yet known about molecular mechanisms underlying immune homeostasis in rice (Oryza sativa). In this study, we reveal that a rice calcium-dependent protein kinase (CDPK), OsCPK17, interacts with and stabilizes the receptor-like cytoplasmic kinase (RLCK) OsRLCK176, a close homolog of Arabidopsis thaliana BOTRYTIS-INDUCED KINASE 1 (AtBIK1). Oxidative burst and pathogenesis-related gene expression triggered by pathogen-associated molecular patterns are significantly attenuated in the oscpk17 mutant. The oscpk17 mutant and OsCPK17-silenced lines are more susceptible to bacterial diseases than the wild-type plants, indicating that OsCPK17 positively regulates rice immunity. Furthermore, the plant U-box (PUB) protein OsPUB12 ubiquitinates and degrades OsRLCK176. OsCPK17 phosphorylates OsRLCK176 at Ser83, which prevents the ubiquitination of OsRLCK176 by OsPUB12 and thereby enhances the stability and immune function of OsRLCK176. The phenotypes of the ospub12 mutant in defense responses and disease resistance show that OsPUB12 negatively regulates rice immunity. Therefore, OsCPK17 and OsPUB12 reciprocally maintain OsRLCK176 homeostasis and function as positive and negative immune regulators, respectively. This study uncovers positive crosstalk between CDPK- and RLCK-mediated immune signaling in plants and reveals that OsCPK17, OsPUB12, and OsRLCK176 maintain rice immune homeostasis.

8.
J Fungi (Basel) ; 9(8)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37623603

RESUMO

Rice false smut caused by Ustilaginoidea virens is one of the most devastating fungal diseases of rice (Oryza sativa) worldwide. Prochloraz and azoxystrobin belong to the groups of demethylation inhibitors and quinone outside inhibitors, respectively, and are commonly used for controlling this disease. In this study, we analyzed the sensitivities of 100 U. virens isolates from Yunnan, Sichuan, Chongqing, and Zhejiang in Southern China to prochloraz and azoxystrobin. The ranges of EC50 for prochloraz and azoxystrobin were 0.004-0.536 and 0.020-0.510 µg/mL, with means and standard errors of 0.062 ± 0.008 and 0.120 ± 0.007 µg/mL, respectively. However, the sensitivity frequency distributions of U. virens to prochloraz and azoxystrobin indicated the emergence of subpopulations with decreased sensitivity. Therefore, the mean EC50 values of 74% and 68% of the isolates at the main peak, 0.031 ± 0.001 and 0.078 ± 0.004 µg/mL, were used as the sensitivity baselines of U. virens to prochloraz and azoxystrobin, respectively. We found significant sensitivity differences to azoxystrobin among different geographical populations and no correlation between the sensitivities of U. virens to prochloraz and azoxystrobin. Among 887 U. virens isolates, the isolate 5-3-1 from Zhejiang showed moderate resistance to prochloraz, with a resistance factor of 22.45, while no nucleotide variation in the 1986-bp upstream or 1827-bp gene regions of CYP51 from 5-3-1 was detected. Overexpression of CYP51 is probably responsible for its resistance to prochloraz. Finally, artificial inoculation showed that 5-3-1 was highly pathogenic to rice, suggesting that the resistance of U. virens to prochloraz must be monitored and managed in Zhejiang.

9.
J Agric Food Chem ; 71(35): 13124-13136, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37615365

RESUMO

Ustilaginoidea virens, the causal agent of rice false smut, produces a large amount of mycotoxins, including ustilaginoidins and sorbicillinoids. However, little is known about the regulatory mechanism of mycotoxin biosynthesis inU. virens. Here, we demonstrate that the NAD+-dependent histone deacetylase UvHST2 negatively regulates ustilaginoidin biosynthesis. UvHst2 knockout caused retarded hypha growth and reduced conidiation and pathogenicity inU. virens. Transcriptome analysis revealed that the transcription factor genes, transporter genes, and other tailoring genes in eight biosynthetic gene clusters (BGCs) including ustilaginoidin and sorbicillinoid BGCs were upregulated in ΔUvhst2. Interestingly, the UvHst2 deletion affects alternative splicing. Metabolomics revealed that UvHST2 negatively regulates the biosynthesis of various mycotoxins including ustilaginoidins, sorbicillin, ochratoxin B, zearalenone, and O-M-sterigmatocystin. Combined transcriptome and metabolome analyses uncover that UvHST2 positively regulates pathogenicity but negatively modulates the expression of BGCs involved in secondary metabolism. Collectively, UvHST2 functions as a global regulator of secondary metabolism inU. virens.


Assuntos
Hypocreales , Micotoxinas , Metabolismo Secundário , Histona Desacetilases
10.
J Integr Plant Biol ; 65(10): 2380-2394, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37534615

RESUMO

Mitogen-activated protein kinase (MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly controlled, but the underlying mechanism remains unclear. Here, we identified Arabidopsis CPL1 (C-terminal domain phosphatase-like 1) as a negative regulator of microbe-associated molecular pattern (MAMP)-triggered immunity via a forward-genetic screen. Disruption of CPL1 significantly enhanced plant resistance to Pseudomonas pathogens induced by the bacterial peptide flg22. Furthermore, flg22-induced MPK3/MPK4/MPK6 phosphorylation was dramatically elevated in cpl1 mutants but severely impaired in CPL1 overexpression lines, suggesting that CPL1 might interfere with flg22-induced MAPK activation. Indeed, CPL1 directly interacted with MPK3 and MPK6, as well as the upstream MKK4 and MKK5. A firefly luciferase-based complementation assay indicated that the interaction between MKK4/MKK5 and MPK3/MPK6 was significantly reduced in the presence of CPL1. These results suggest that CPL1 plays a novel regulatory role in suppressing MAMP-induced MAPK cascade activation and MAMP-triggered immunity to bacterial pathogens.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas Quinases Ativadas por Mitógeno/genética , Arabidopsis/metabolismo , RNA Polimerase II/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas de Arabidopsis/metabolismo , Monoéster Fosfórico Hidrolases/genética , Regulação da Expressão Gênica de Plantas , Imunidade Vegetal/genética , Fosfoproteínas Fosfatases/genética , Fatores de Transcrição/metabolismo , Proteínas de Ligação a RNA/metabolismo
11.
Mol Plant Pathol ; 24(11): 1414-1429, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37452482

RESUMO

Rice false smut, caused by the ascomycete fungus Ustilaginoidea virens, which infects rice florets before heading, severely threatens rice grain yield and quality worldwide. The U. virens genome encodes a number of glycoside hydrolase (GH) proteins. So far, the functions of these GHs in U. virens are largely unknown. In this study, we identified a GH42 protein secreted by U. virens, named UvGHF1, that exhibits ß-galactosidase activity. UvGHF1 not only functions as an essential virulence factor during U. virens infection, but also serves as a pathogen-associated molecular pattern (PAMP) in Nicotiana benthamiana and rice. The PAMP activity of UvGHF1 is independent of its ß-galactosidase activity. Moreover, UvGHF1 triggers cell death in N. benthamiana in a BAK1-dependent manner. Ectopic expression of UvGHF1 in rice induces pattern-triggered immunity and enhances rice resistance to fungal and bacterial diseases. RNA-seq analysis revealed that UvGHF1 expression in rice not only activates expression of many defence-related genes encoding leucine-rich repeat receptor-like kinases and WRKY and ERF transcription factors, but also induces diterpenoid biosynthesis and phenylpropanoid biosynthesis pathways. Therefore, UvGHF1 contributes to U. virens virulence, but is also recognized by the rice surveillance system to trigger plant immunity.


Assuntos
Oryza , Fatores de Virulência , Fatores de Virulência/genética , Glicosídeo Hidrolases/genética , Doenças das Plantas/microbiologia , Oryza/microbiologia , Imunidade Vegetal , beta-Galactosidase
12.
Stem Cell Res ; 71: 103149, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37356183

RESUMO

The ß-amyloid precursor protein (APP) is a crucial pathogenic gene linked to Alzheimer's disease (AD). A human induced pluripotent stem cell (iPSC) line was generated from peripheral blood mononuclear cells (PBMCs) isolated from a female with APP gene mutation utilizing non-integrative Sendai virus. The iPSC line exhibits high expression of pluripotency markers, retains the APP mutation, displays a normal karyotype, and has the ability to differentiate into normal teratoma tissue. This iPSC line represents a valuable cell model for investigating the pathological mechanisms and therapeutic strategies of AD.


Assuntos
Doença de Alzheimer , Células-Tronco Pluripotentes Induzidas , Humanos , Feminino , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Leucócitos Mononucleares/metabolismo , Doença de Alzheimer/patologia , Mutação/genética , Diferenciação Celular
13.
Phytopathology ; 113(7): 1244-1253, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36706002

RESUMO

The root rot disease caused by Fusarium oxysporum f. sp. ginseng is one of the most destructive diseases of ginseng, an economically important herb. However, little is known about the pathogen's toxin biosynthesis or the molecular mechanisms regulating infection of ginseng. In this study we identified and functionally characterized the FoRSR1 gene that encodes a Ras-related (RSR) small GTPase homologous to yeast Rsr1 in F. oxysporum f. sp. ginseng. Disruption of FoRSR1 resulted in a significant reduction in mycelial dry weight in liquid cultures, although vegetative growth rate was not affected on culture plates. Notably, the Forsr1 mutant exhibited blunted and swollen hyphae with multi-nucleated compartments. It produced fewer and morphologically abnormal conidia and was defective in chlamydospore formation. In infection assays with ginseng roots, the Forsr1 mutant was significantly less virulent and caused only limited necrosis at the wounding sites. Deletion of FoRSR1 also affected pigmentation, autophagy, and production of fusaric acid. Furthermore, the expression of many candidate genes involved in secondary metabolism was significantly downregulated in the mutant, suggesting that FoRSR1 is also important for secondary metabolism. Overall, our results indicated that FoRSR1 plays important roles in conidiation, vacuolar morphology, secondary metabolism, and pathogenesis in F. oxysporum f. sp. ginseng.


Assuntos
Fusarium , Panax , Virulência/genética , Ácido Fusárico/metabolismo , Doenças das Plantas , Saccharomyces cerevisiae
14.
Environ Monit Assess ; 195(2): 340, 2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36708486

RESUMO

Soil erosion and nutrient loss are important environmental and ecological problems in the Dianchi watershed in southwestern China. Woodlands-the primary land type in the Dianchi watershed-play an important ecological role in controlling soil and water loss. In this study, we compared soil erosion and loss of total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) in woodlands of different ages, i.e., young forest, medium forest, and near-mature forest, at the Dongda River catchment in south-western Dianchi watershed. Furthermore, changes in stoichiometries in soil were analyzed. The average degree of erosion of each forest age stage was below moderate. Based on the non-arable soil erosion modulus models of 137Cs and 210Pbex, the soil erosion rates decreased gradually with the increasing forest age. The forest age affected soil nutrient distribution and loss. The losses of TOC and TP gradually decreased, while the losses of TN first increased and then decreased with the growth of forest age. TOC, TN, and TP were enriched in the topsoil. Forest age affected soil stoichiometry and soil nutrient supply level. In general, the forest can effectively reduce soil erosion and nutrient loss in the red soil area with the forest age increasing.


Assuntos
Monitoramento Ambiental , Erosão do Solo , Florestas , China , Solo , Nitrogênio/análise , Fósforo/análise
15.
J Environ Manage ; 328: 116944, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36525734

RESUMO

Pollution from polycyclic aromatic hydrocarbons (PAHs) spreads and changes worldwide. The pollution evolution in the regional water environment evolves in response to multiple factors, requiring considerable attention. PAH heterogeneity in the sediment core from Chaihe Reservoir was investigated to indicate dynamic changes in PAH pollution levels and sources and propose recommendations for controlling PAHs. Dynamic PAH patterns showed that the overall decline in PAH pollution was in association with local anthropogenic activities, temperature, and precipitation over the period 1863-2018. Nevertheless, coal, oil, and natural gas consumptions still played significant roles in transferring PAHs to the reservoir. Meanwhile, there were dominant local origins, including grass, wood, and coal combustion. The results highlight that the joint action of natural and anthropogenic interventions mitigated PAH pollution in the reservoir. Promoting improved fuels, new energy vehicles, and cleaner energy may further lower PAH pollution.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Sedimentos Geológicos , Monitoramento Ambiental/métodos , Carvão Mineral/análise , China
16.
Phytopathology ; 113(3): 549-558, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36346376

RESUMO

Rice false smut, caused by Ustilaginoidea virens, has become one of the most devastating grain diseases of rice worldwide. Understanding the genetic diversity of U. virens is essential for efficient disease control and breeding for disease resistance. However, little is known about the genetic variation of U. virens from different rice cultivars. We investigated the genetic diversity and pathogenic variation of U. virens isolates from 10 rice cultivars in Zhejiang, China. A total of 260 polymorphic loci and 27 haplotypes were identified based on the 2,137-bp combined DNA fragments of all individuals; hap_4 was the most common haplotype, represented by 41 isolates. Phylogeny indicated that all isolates were divided into four genetic groups. Group I was the largest, with 98 isolates, distributed mainly in eight cultivar populations, whereas 90% of the isolates collected from a Changxiang cultivar were clustered in Group IV. Furthermore, the pairwise FST values exhibited significant genetic differentiation in 27 of the pairwise comparisons between populations, accounting for 23.21% of the total genetic variation. The genetic composition of the isolates of the CX population was distinguishable from that of the other nine populations, and genetic recombination was found in a few isolates. Finally, 27 haplotype representative isolates showed high variation in pathogenicity, and the isolates from the genetic subpopulation I were likely to be more virulent than those from genetic subpopulations II and III. Collectively, these findings suggest that differences in rice cultivars play an important role in the genetic variation of U. virens.


Assuntos
Hypocreales , Oryza , Ustilaginales , Oryza/genética , Doenças das Plantas , Melhoramento Vegetal , Hypocreales/genética , Variação Genética
17.
Mol Plant Microbe Interact ; 35(12): 1120-1123, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36510363

RESUMO

Rice false smut (RFS), caused by Ustilaginoidea virens, has become a major disease in recent years, and mycotoxins produced by U. virens often threaten food safety. To study fungal pathogenesis and identify potential targets for developing new fungicides, gap-free nuclear and complete mitochondrial genomes of U. virens JS60-2 were sequenced and assembled. Using the second and third generation sequencing data, we assembled a 38.02-Mb genome that consists of seven contigs with the contig N50 being 6.32-Mb. In total, 8,486 protein-coding genes were annotated in the genome, including 21 secondary metabolism gene clusters. We also assembled the complete mitochondrial genome, which is 102,498 bp, with 28% GC content. The JS60-2 genomes assembled in this study will facilitate research on U. virens and contribute to RFS control. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Genoma Mitocondrial , Hypocreales , Oryza , Oryza/microbiologia , Doenças das Plantas/microbiologia , Hypocreales/genética
18.
Int J Mol Sci ; 23(18)2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36142440

RESUMO

Rice false smut caused by the biotrophic fungal pathogen Ustilaginoidea virens has become one of the most important diseases in rice. The large effector repertory in U. virens plays a crucial role in virulence. However, current knowledge of molecular mechanisms how U. virens effectors target rice immune signaling to promote infection is very limited. In this study, we identified and characterized an essential virulence effector, SCRE4 (Secreted Cysteine-Rich Effector 4), in U. virens. SCRE4 was confirmed as a secreted nuclear effector through yeast secretion, translocation assays and protein subcellular localization, as well as up-regulation during infection. The SCRE4 gene deletion attenuated the virulence of U. virens to rice. Consistently, ectopic expression of SCRE4 in rice inhibited chitin-triggered immunity and enhanced susceptibility to false smut, substantiating that SCRE4 is an essential virulence factor. Furthermore, SCRE4 transcriptionally suppressed the expression of OsARF17, an auxin response factor in rice, which positively regulates rice immune responses and resistance against U. virens. Additionally, the immunosuppressive capacity of SCRE4 depended on its nuclear localization. Therefore, we uncovered a virulence strategy in U. virens that transcriptionally suppresses the expression of the immune positive modulator OsARF17 through nucleus-localized effector SCRE4 to facilitate infection.


Assuntos
Hypocreales , Oryza , Quitina/metabolismo , Cisteína/metabolismo , Hypocreales/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/genética , Oryza/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Fatores de Virulência/metabolismo
19.
New Phytol ; 236(4): 1422-1440, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36068953

RESUMO

Rice false smut caused by Ustilaginoidea virens is becoming one of the most recalcitrant rice diseases worldwide. However, the molecular mechanisms underlying rice immunity against U. virens remain unknown. Using genetic, biochemical and disease resistance assays, we demonstrated that the xb24 knockout lines generated in non-Xa21 rice background exhibit an enhanced susceptibility to the fungal pathogens U. virens and Magnaporthe oryzae. Consistently, flg22- and chitin-induced oxidative burst and expression of pathogenesis-related genes in the xb24 knockout lines were greatly attenuated. As a central mediator of energy signaling, SnRK1A interacts with and phosphorylates XB24 at Thr83 residue to promote ATPase activity. SnRK1A is activated by pathogen-associated molecular patterns and positively regulates plant immune responses and disease resistance. Furthermore, the virulence effector SCRE1 in U. virens targets host ATPase XB24. The interaction inhibits ATPase activity of XB24 by blocking ATP binding to XB24. Meanwhile, SCRE1 outcompetes SnRK1A for XB24 binding, and thereby suppresses SnRK1A-mediated phosphorylation and ATPase activity of XB24. Our results indicate that the conserved SnRK1A-XB24 module in multiple crop plants positively contributes to plant immunity and uncover an unidentified molecular strategy to promote infection in U. virens and a novel host target in fungal pathogenesis.


Assuntos
Oryza , Oryza/metabolismo , Adenosina Trifosfatases/metabolismo , Fosforilação , Doenças das Plantas/microbiologia , Resistência à Doença , Moléculas com Motivos Associados a Patógenos/metabolismo , Quitina/metabolismo , Trifosfato de Adenosina/metabolismo
20.
Environ Sci Pollut Res Int ; 29(51): 76739-76751, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35670938

RESUMO

Lake sediment records the evolution process of the interaction between human and nature. It is important to master the lacustrine sedimentation rate for the ecological environment assessment of catchment. A 60-cm sediment core was collected in the Da River Reservoir during 2019 to analyze radionuclides (210Pb and 137Cs) massic activities, grain size, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and metals (Mn, Cu, Al, and Pb) mass fractions to reconstruct the response of sedimentation rate to environmental evolution. The environmental changes in the small catchment were classified into the following three stages through cluster analysis (CA) for geochemical parameters in the sediment core: phase I (1881-1985), phase II (1987-1999), and phase III (2000-2018). The average depth sedimentation rates (ADSRs) of the three stages were 0.33, 0.90, and 1.50 cm/year, respectively. The sedimentation rates increased from the bottom to the surface layer, indicating that the exogenous inputs into the reservoir have been occurring. The sediment deposition in phase III was strongly disturbed by the environmental changes (such as warmer climate and intensified land use). Therefore, sedimentation rates showed a rapid increase. Both Pearson correlation analysis and redundancy analysis (RDA) showed that sedimentation rates were positively correlated with climatic factors, particle size, nutrients and metals mass fractions, elemental ratios, and socioeconomic parameters. Sedimentation rates show high sensitivity to anthropogenic activities and climatic change, which can be used to reconstruct the environmental evolution process at a small catchment scale.


Assuntos
Sedimentos Geológicos , Rios , Humanos , Sedimentos Geológicos/análise , Monitoramento Ambiental , Chumbo/análise , Lagos/análise , Fósforo/análise , Nitrogênio/análise , Carbono/análise , China
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