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1.
EMBO J ; 42(9): e112634, 2023 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-36891678

RESUMEN

In response to infection, plants can induce the production of reactive oxygen species (ROS) to restrict pathogen invasion. In turn, adapted pathogens have evolved a counteracting mechanism of enzymatic ROS detoxification, but how it is activated remains elusive. Here, we show that in the tomato vascular wilt pathogen Fusarium oxysporum f. sp. lycopersici (Fol) this process is initiated by deacetylation of the FolSrpk1 kinase. Upon ROS exposure, Fol decreases FolSrpk1 acetylation on the K304 residue by altering the expression of the acetylation-controlling enzymes. Deacetylated FolSrpk1 disassociates from the cytoplasmic FolAha1 protein, thus enabling its nuclear translocation. Increased accumulation of FolSrpk1 in the nucleus allows for hyperphosphorylation of its phosphorylation target FolSr1 that subsequently enhances transcription of different types of antioxidant enzymes. Secretion of these enzymes removes plant-produced H2 O2 , and enables successful Fol invasion. Deacetylation of FolSrpk1 homologs has a similar function in Botrytis cinerea and likely other fungal pathogens. These findings reveal a conserved mechanism for initiation of ROS detoxification upon plant fungal infection.


Asunto(s)
Antioxidantes , Fusarium , Especies Reactivas de Oxígeno/metabolismo , Enfermedades de las Plantas/microbiología
2.
New Phytol ; 241(4): 1732-1746, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38037458

RESUMEN

Lysine acetylation is an evolutionarily conserved and widespread post-translational modification implicated in the regulation of multiple metabolic processes, but its function remains largely unknown in plant pathogenic fungi. A comprehensive analysis combined with proteomic, molecular and cellular approaches was presented to explore the roles of cytoplasmic acetylation in Fusarium oxsysporum f.sp. lycopersici (Fol). The divergent cytoplasmic deacetylase FolSir2 was biochemically characterized, which is contributing to fungal virulence. Based on this, a total of 1752 acetylated sites in 897 proteins were identified in Fol via LC-MS/MS analysis. Further analyses of the quantitative acetylome revealed that 115 proteins representing two major pathways, translational and ribosome biogenesis, were hyperacetylated in the ∆Folsir2 strain. We experimentally examined the regulatory roles of FolSir2 on K271 deacetylation of FolGsk3, a serine/tyrosine kinase implicated in a variety of cellular functions, which was found to be crucial for the activation of FolGsk3 and thus modulated Fol pathogenicity. Cytoplasmic deacetylation by FolSir2 homologues has a similar function in Botrytis cinerea and likely other fungal pathogens. These findings reveal a conserved mechanism of silent information regulator 2-mediated cytoplasmic deacetylation that is involved in plant-fungal pathogenicity, providing a candidate target for designing broad-spectrum fungicides to control plant diseases.


Asunto(s)
Fusarium , Proteómica , Cromatografía Liquida , Espectrometría de Masas en Tándem , Hongos , Procesamiento Proteico-Postraduccional , Enfermedades de las Plantas/microbiología
3.
Mol Cell Proteomics ; 21(5): 100231, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35398590

RESUMEN

Fusarium oxysporum is one of the most abundant and diverse fungal species found in soils and includes nonpathogenic, endophytic, and pathogenic strains affecting a broad range of plant and animal hosts. Conidiation is the major mode of reproduction in many filamentous fungi, but the regulation of this process is largely unknown. Lysine acetylation (Kac) is an evolutionarily conserved and widespread posttranslational modification implicated in regulation of multiple metabolic processes. A total of 62 upregulated and 49 downregulated Kac proteins were identified in sporulating mycelia versus nonsporulating mycelia of F. oxysporum. Diverse cellular proteins, including glycolytic enzymes, ribosomal proteins, and endoplasmic reticulum-resident molecular chaperones, were differentially acetylated in the sporulation process. Altered Kac levels of three endoplasmic reticulum-resident molecular chaperones, PDIK70, HSP70K604, and HSP40K32 were identified that with important roles in F. oxysporum conidiation. Specifically, K70 acetylation (K70ac) was found to be crucial for maintaining stability and activity of protein disulphide isomerase and the K604ac of HSP70 and K32ac of HSP40 suppressed the detoxification ability of these heat shock proteins, resulting in higher levels of protein aggregation. During conidial formation, an increased level of PDIK70ac and decreased levels of HSP70K604ac and HSP40K32ac contributed to the proper processing of unfolded proteins and eliminated protein aggregation, which is beneficial for dramatic cell biological remodeling during conidiation in F. oxysporum.


Asunto(s)
Agregado de Proteínas , Proteómica , Acetilación , Animales , Fusarium , Chaperonas Moleculares , Procesamiento Proteico-Postraduccional , Proteómica/métodos
4.
Mol Cell ; 58(3): 431-9, 2015 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-25891074

RESUMEN

Repetitive extragenic palindromic (REP) sequences are highly structured elements found downstream of ∼500 genes in Escherichia coli that result in extensive stem-loop structures in their mRNAs. However, their physiological role has remained elusive. Here, we show that REP sequences can downregulate translation, but only if they are within 15 nt of a termination codon; a spacing of 16 nt has no effect, suggesting that the REP element acts to stall ribosome movement. Ribosome stalling leads to cleavage of the mRNA and induction of the trans-translation process. Using nrdAB as a model, we find that its regulation can be partially reversed by overexpression of RNA helicases and can be fully overcome upon UV stress, emphasizing the importance of this regulatory process. Since 50% of REP-associated genes have these elements within the critical 15 nt, these findings identify a regulatory mechanism with the potential to affect translation from a large number of genes.


Asunto(s)
Proteínas de Escherichia coli/genética , Biosíntesis de Proteínas , ARN Mensajero/genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Northern Blotting , Escherichia coli/genética , Escherichia coli/metabolismo , Modelos Genéticos , Estabilidad del ARN , ARN Mensajero/metabolismo , Ribonucleósido Difosfato Reductasa/genética , Ribonucleótido Reductasas/genética
5.
Phytopathology ; 112(6): 1264-1272, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34982575

RESUMEN

Botrytis cinerea causes gray mold resulting in enormous financial loss. Fungicide resistance of B. cinerea has become a serious issue in food safety and agricultural environmental protection. Sodium valproate (SV) has been used in clinical trials; thus, it is an excellent candidate for fungicide development, considering its safety. However, the antifungal activity remains unclear. SV was effective against B. cinerea by enhancing acetylation of histone H3, including H3K9ac, H3K14ac, and H3K56ac. A transcriptomics analysis revealed that the expression of 1,557 genes changed significantly in response to SV. A pathway enrichment analysis identified 16 significant GO terms, in which molecular functions were mainly involved. In addition, the expression levels of 13 genes involved in B. cinerea virulence and five genes involved in tomato immune response were altered by the SV treatment. These results indicate that SV inhibits B. cinerea by enhancing acetylation of histone H3 and modifying gene transcription. Thus, SV is an effective, safe, potential antifungal agent for control of both pre- and postharvest losses caused by B. cinerea.


Asunto(s)
Fungicidas Industriales , Solanum lycopersicum , Acetilación , Antifúngicos/metabolismo , Botrytis/genética , Frutas/microbiología , Fungicidas Industriales/metabolismo , Fungicidas Industriales/farmacología , Histonas/genética , Histonas/metabolismo , Inmunidad , Solanum lycopersicum/genética , Solanum lycopersicum/microbiología , Enfermedades de las Plantas/microbiología , Transcripción Genética , Ácido Valproico/metabolismo , Ácido Valproico/farmacología
6.
Phytopathology ; 111(7): 1152-1157, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33289404

RESUMEN

Tetrandrine (TET) is a potent calcium channel blocker used to treat hypertension and inflammation. Currently, TET is predominantly used to treat a variety of human diseases, and there is little information regarding the use of TET against plant pathogens. In this study, we explored the antifungal activity of TET on a plant pathogen, Botrytis cinerea. We show that administration of low concentrations of TET effectively inhibited hyphal growth of fungus grown on potato dextrose agarose and decreased the virulence of B. cinerea in tomato plants. Real-time PCR revealed that the expression of drug efflux pump-related genes (alcohol dehydrogenase 1, multidrug/pheromone exporter, pleiotropic drug resistance protein 1, and synaptic vesicle transporter) were downregulated in the presence of TET. Finally, we show that TET acts synergistically with iprodione, resulting in increased inhibition of B. cinerea both in vitro and in vivo. These results indicate that TET might act as an effective antifungal agent in reducing gray mold disease.


Asunto(s)
Antifúngicos , Botrytis , Antifúngicos/farmacología , Bencilisoquinolinas , Enfermedades de las Plantas , Virulencia
7.
Plant Dis ; 105(5): 1356-1364, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33258433

RESUMEN

Photinia (Photinia × fraseri Dress) is a well-known green plant that has high ornamental value and is widely distributed around the world. An outbreak of typical bud blight disease was observed between May and August in photinia in 2017 in Qingdao, China. The causal agent for this blight was subsequently isolated from symptomatic samples and identified as Nothophoma quercina based on morphological characterization and molecular analyses (ITS, LSU, RPB2, and TUB2). Results of pathogenicity tests on isolated fungi also supported the conclusion that N. quercina is the pathogen responsible for this condition. To our knowledge, this is the first report of bud blight on P. fraseri caused by N. quercina in China.


Asunto(s)
Ascomicetos , Photinia , Ascomicetos/genética , China
8.
Mol Plant Microbe Interact ; 33(10): 1242-1251, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32689887

RESUMEN

Histone acetyltransferase plays a critical role in transcriptional regulation by increasing accessibility of target genes to transcriptional activators. Botrytis cinerea is an important necrotrophic fungal pathogen with worldwide distribution and a very wide host range, but little is known of how the fungus regulates the transition from saprophytic growth to infectious growth. Here, the function of BcSas2, a histone acetyltransferase of B. cinerea, was investigated. Deletion of the BcSAS2 gene resulted in significantly reduced acetylation levels of histone H4, particularly of H4K16ac. The deletion mutant ΔBcSas2.1 was not only less pathogenic but also more sensitive to oxidative stress than the wild-type strain. RNA-Seq analysis revealed that a total of 13 B. cinerea genes associated with pathogenicity were down-regulated in the ΔBcSas2.1 mutant. Independent knockouts of two of these genes, BcXYGA (xyloglucanase) and BcCAT (catalase), led to dramatically decreased virulence and hypersensitivity to oxidative stress, respectively. Chromatin immunoprecipitation followed by quantitative PCR confirmed that BcSas2 bound directly to the promoter regions of both these pathogenicity-related genes. These observations indicated that BcSas2 regulated the transcription of pathogenicity-related genes by controlling the acetylation level of H4K16, thereby affecting the virulence and oxidative sensitivity of B. cinerea.


Asunto(s)
Botrytis/fisiología , Histonas , Estrés Oxidativo , Acetilación , Botrytis/genética , Botrytis/patogenicidad , Catalasa/genética , Genes Fúngicos , Glicósido Hidrolasas/genética , Histonas/genética , Enfermedades de las Plantas/microbiología , Virulencia
9.
Mol Cell ; 44(1): 160-6, 2011 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-21981926

RESUMEN

RNase R, an Escherichia coli exoribonuclease important for degradation of structured RNAs, increases 3- to 10-fold under certain stress conditions, due to an increased half-life for this usually unstable protein. Components of the trans-translation machinery, tmRNA, and its associated protein, SmpB, are essential for RNase R instability. However, it is not understood why exponential phase RNase R is unstable or how it becomes stabilized in stationary phase. Here, we show that these phenomena are regulated by acetylation catalyzed by YfiQ protein. One residue, Lys544, is acetylated in exponential phase RNase R, but not in the stationary phase protein, resulting in tighter binding of tmRNA-SmpB to the C-terminal region of exponential phase RNase R and subsequent proteolytic degradation. Removal of the positive charge at Lys544 or a negative charge in the C-terminal region likely disrupts their interaction, facilitating tmRNA-SmpB binding. These findings indicate that acetylation can regulate the stability of a bacterial protein.


Asunto(s)
Proteínas Bacterianas/metabolismo , Exorribonucleasas/metabolismo , Regulación Bacteriana de la Expresión Génica , Acetilación , Acetiltransferasas/metabolismo , Catálisis , Escherichia coli/enzimología , Proteínas de Escherichia coli/metabolismo , Lisina/química , Mutación , Unión Proteica , Estructura Terciaria de Proteína , Proteolisis , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , Proteínas de Unión al ARN/metabolismo
10.
BMC Genomics ; 19(1): 209, 2018 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-29558883

RESUMEN

BACKGROUND: Protein lysine malonylation, a newly discovered post-translational modification (PTM), plays an important role in diverse metabolic processes in both eukaryotes and prokaryotes. Common wheat is a major global cereal crop. However, the functions of lysine malonylation are relatively unknown in this crop. Here, a global analysis of lysine malonylation was performed in wheat. RESULTS: In total, 342 lysine malonylated sites were identified in 233 proteins. Bioinformatics analysis showed that the frequency of arginine (R) in position + 1 was highest, and a modification motif, KmaR, was identified. The malonylated proteins were located in multiple subcellular compartments, especially in the cytosol (45%) and chloroplast (30%). The identified proteins were found to be involved in diverse pathways, such as carbon metabolism, the Calvin cycle, and the biosynthesis of amino acids, suggesting an important role for lysine malonylation in these processes. Protein interaction network analysis revealed eight highly interconnected clusters of malonylated proteins, and 137 malonylated proteins were mapped to the protein network database. Moreover, five proteins were simultaneously modified by lysine malonylation, acetylation and succinylation, suggesting that these three PTMs may coordinately regulate the function of many proteins in common wheat. CONCLUSIONS: Our results suggest that lysine malonylation is involved in a variety of biological processes, especially carbon fixation in photosynthetic organisms. These data represent the first report of the lysine malonylome in common wheat and provide an important dataset for further exploring the physiological role of lysine malonylation in wheat and likely all plants.


Asunto(s)
Lisina/metabolismo , Malonatos/metabolismo , Proteínas de Plantas/metabolismo , Procesamiento Proteico-Postraduccional , Proteoma/análisis , Triticum/metabolismo , Biología Computacional , Proteómica/métodos
11.
Artículo en Inglés | MEDLINE | ID: mdl-29055818

RESUMEN

Yarrowia lipolytica is considered as a promising microbial cell factory for bio-oil production due to its ability to accumulate a large amount of lipid. However, the regulation of lipid metabolism in this oleaginous yeast is elusive. In this study, the MHY1 gene was disrupted, and 43.1% (w/w) intracellular oil based on cell dry weight was obtained from the disruptant M-MHY1, while only 30.2% (w/w) lipid based on cell dry weight was obtained from the reference strain. RNA-seq was then performed to analyze transcriptional changes during lipid biosynthesis after MHY1 gene inactivation. The expression of 1597 genes, accounting for 24.7% of annotated Y. lipolytica genes, changed significantly in the disruptant M-MHY1 during lipid biosynthesis. Differential gene expression analysis indicated that Mhy1p performs multiple functions and participates in a wide variety of biological processes, including lipid, amino acid and nitrogen metabolism. Notably, data analysis revealed increased carbon flux through lipid biosynthesis following MHY1 gene inactivation, accompanied by decreased carbon flux through amino acid biosynthesis. Moreover, Mhy1p regulates the cell cycle, and the cell cycle rate was enhanced in the disruptant M-MHY1. These results suggest that Mhy1p plays critical regulatory roles in diverse aspects of various biological processes, especially in lipid biosynthesis, amino acid and nitrogen metabolism and cell cycle. Our dataset appears to elucidate the crucial role of Mhy1p in lipid biosynthesis and serves as a resource for exploring physiological dimorphic growth in Y. lipolytica.


Asunto(s)
Proteínas de Unión al ADN/fisiología , Proteínas Fúngicas/fisiología , Metabolismo de los Lípidos/genética , Yarrowia/genética , Yarrowia/metabolismo , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Lípidos/biosíntesis , Lipogénesis/genética , Redes y Vías Metabólicas/genética , Organismos Modificados Genéticamente , Aceites de Plantas , Polifenoles/biosíntesis , Transcriptoma
12.
Nucleic Acids Res ; 44(5): 1979-88, 2016 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-26847092

RESUMEN

RNase II, a 3' to 5' processive exoribonuclease, is the major hydrolytic enzyme in Escherichia coli accounting for ∼90% of the total activity. Despite its importance, little is actually known about regulation of this enzyme. We show here that one residue, Lys501, is acetylated in RNase II. This modification, reversibly controlled by the acetyltransferase Pka, and the deacetylase CobB, affects binding of the substrate and thus decreases the catalytic activity of RNase II. As a consequence, the steady-state level of target RNAs of RNase II may be altered in the cells. We also find that under conditions of slowed growth, the acetylation level of RNase II is elevated and the activity of RNase II decreases, emphasizing the importance of this regulatory process. These findings indicate that acetylation can regulate the activity of a bacterial ribonuclease.


Asunto(s)
Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Exorribonucleasas/metabolismo , Regulación Bacteriana de la Expresión Génica , Lisina/metabolismo , Procesamiento Proteico-Postraduccional , Acetilación , Acetiltransferasas/genética , Acetiltransferasas/metabolismo , Dominio Catalítico , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Exorribonucleasas/genética , Unión Proteica , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , Sirtuinas/genética , Sirtuinas/metabolismo
13.
Bioprocess Biosyst Eng ; 41(11): 1707-1716, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30069713

RESUMEN

Microbial oils can be used for biodiesel production and fumaric acid (FA) is widely used in the food and chemical industries. In this study, the production of lipids and FA by Aureobasidium pullulans var. aubasidani DH177 was investigated. A high initial carbon/nitrogen ratio in the medium promoted the accumulation of lipids and FA. When the medium contained 12.0% glucose and 0.2% NH4NO3, the yeast strain DH177 accumulated 64.7% (w/w) oil in its cells, 22.4 g/l cell biomass and 32.3 g/l FA in a 5-L batch fermentation. The maximum yields of oil and FA were 0.12 g/g and 0.27 g/g of consumed sugar, respectively. The compositions of the produced fatty acids were C14:0 (0.6%), C16:0 (24.9%), C16:1 (4.4%), C18:0 (2.1%), C18:1 (57.6%), and C18:2 (10.2%). Biodiesel obtained from the extracted oil burned well. This study provides the pioneering utilization of the yeast strain DH177 for the integrated production of oil and FA.


Asunto(s)
Ascomicetos/metabolismo , Fumaratos/metabolismo , Aceites/metabolismo , Secuencia de Aminoácidos , Ascomicetos/genética , Ascomicetos/aislamiento & purificación , Biocombustibles , Biomasa , Reactores Biológicos/microbiología , Fermentación , Fumarato Hidratasa/genética , Fumarato Hidratasa/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Genes Fúngicos , Microbiología Industrial , Cinética , Lípidos/biosíntesis , Filogenia , Homología de Secuencia de Aminoácido
14.
BMC Genomics ; 18(1): 309, 2017 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-28427325

RESUMEN

BACKGROUND: Protein lysine succinylation is an important post-translational modification and plays a critical regulatory role in almost every aspects of cell metabolism in both eukaryotes and prokaryotes. Common wheat is one of the major global cereal crops. However, to date, little is known about the functions of lysine succinylation in this plant. Here, we performed a global analysis of lysine succinylation in wheat and examined its overlap with lysine acetylation. RESULTS: In total, 330 lysine succinylated modification sites were identified in 173 proteins. Bioinformatics analysis showed that the modified proteins are distributed in multiple subcellular compartments and are involved in a wide variety of biological processes such as photosynthesis and the Calvin-Benson cycle, suggesting an important role for lysine succinylation in these processes. Five putative succinylation motifs were identified. A protein interaction network analysis revealed that diverse interactions are modulated by protein succinylation. Moreover, 21 succinyl-lysine sites were found to be acetylated at the same position, and 33 proteins were modified by both acetylation and succinylation, suggesting an extensive overlap between succinylation and acetylation in common wheat. Comparative analysis indicated that lysine succinylation is conserved between common wheat and Brachypodium distachyon. CONCLUSIONS: These results suggest that lysine succinylation is involved in diverse biological processes, especially in photosynthesis and carbon fixation. This systematic analysis represents the first global analysis of lysine succinylation in common wheat and provides an important resource for exploring the physiological role of lysine succinylation in this cereal crop and likely in all plants.


Asunto(s)
Lisina/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Procesamiento Proteico-Postraduccional , Proteómica , Ácido Succínico/metabolismo , Triticum/metabolismo , Acetilación , Ciclo del Carbono , Anotación de Secuencia Molecular , Fotosíntesis , Proteínas de Plantas/genética , Estructura Secundaria de Proteína , Transporte de Proteínas , Triticum/citología , Triticum/genética
15.
Plant Dis ; 101(4): 562-567, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30677360

RESUMEN

Cucumber downy mildew, caused by Pseudoperonospora cubensis, is a worldwide disease that causes severe damage to cucumber production. The effects of temperature and moisture on sporulation and infection by P. cubensis were investigated by inoculating cucumber ('85F12') cotyledons with sporangia and examining the sporangia produced on the inoculated cotyledons under artificially controlled environments. The result showed that the temperature required for sporangium infection by P. cubensis and sporulation of the downy mildew lesions occurred at 5 to 30°C. The optimal temperature estimated by the fitted model was 18.8°C for sporangium infection and 16.2°C for downy mildew lesion sporulation. The pathogen formed plenty of sporangia when disease cotyledons were wetted or in the environment with relative humidity = 100%. The downy mildew lesions produced only a few sporangia when placed in the environment with relative humidity = 90%. The inoculated cotyledons, which incubated for 5 days at about 20°C in a dry greenhouse, began to form sporangia 4 h after being wetted when incubated in darkness. The quantity of sporangia produced on the downy mildew lesions increased with extension of incubating period (within 12 h), and the relationship between produced sporangia and the incubation period at 15, 20, and 25°C can be described by three exponential models. The observed minimum wetness durations (MWD) required for sporangia to complete the infection process and cause downy mildew were 12, 4, 2.5, 1, 1, and 6 h for 5, 10, 15, 20, 25, and 30°C, respectively. The effect of temperature and wetness duration on infection by sporangia of P. cubensis can be described by the modified Weibull model. The shortest MWD was 0.45 h, about 27 min, estimated by model. The experimental data and models will be helpful in the development of forecasting models and effective control systems for cucumber downy mildew.

16.
BMC Genomics ; 17(1): 1019, 2016 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-27964708

RESUMEN

BACKGROUND: Lysine acetylation in proteins is a ubiquitous and conserved post-translational modification, playing a critical regulatory role in almost every aspect of living cells. Although known for many years, its function remains elusive in Fusarium graminearum, one of the most important necrotrophic plant pathogens with huge economic impact. RESULTS: By the combination of affinity enrichment and high-resolution LC-MS/MS analysis, large-scale lysine acetylome analysis was performed. In total, 577 lysine acetylation sites matched to 364 different proteins were identified. Bioinformatics analysis of the acetylome showed that the acetylated proteins are involved in a wide range of cellular functions and exhibit diverse subcellular localizations. Remarkably, 10 proteins involved in the virulence or DON (deoxynivalenol) biosynthesis were found to be acetylated, including 4 transcription factors, 4 protein kinases and 2 phosphatases. Protein-protein interaction network analysis revealed that acetylated protein complexes are involved in diversified interactions. CONCLUSIONS: This work provides the first comprehensive survey of a possible lysine acetylome in F. graminearum and reveals previously unappreciated roles of lysine acetylation in the regulation of diverse biological processes. This work provides a resource for functional analysis of acetylated proteins in filamentous fungi.


Asunto(s)
Fusarium/metabolismo , Lisina/metabolismo , Procesamiento Proteico-Postraduccional , Acetilación , Análisis por Conglomerados , Biología Computacional/métodos , Bases de Datos de Proteínas , Fusarium/patogenicidad , Ontología de Genes , Anotación de Secuencia Molecular , Mapeo de Interacción de Proteínas , Mapas de Interacción de Proteínas , Proteoma , Proteómica/métodos , Tricotecenos/biosíntesis , Virulencia
17.
Int J Syst Evol Microbiol ; 66(9): 3456-3462, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27263534

RESUMEN

A Gram-stain-negative, aerobic, non-motile bacterial strain, 7Y-4T, was isolated from bark tissue of Populus × euramericana. The isolate was able to grow between 10 and 37 °C, with optimal growth occurring at 28-30 °C. Strain 7Y-4T was positive for oxidase and catalase activities, but did not reduce nitrite from nitrate. Positive reactions were observed for the activities of ß-galactosidase, urease and ß-glucosidase, but negative reactions for the activities of gelatinase and the production of indole, acetoin and H2S. Citrate was not utilized. The major fatty acids of strain 7Y-4T are iso-C15 : 0 (28.6 %), C16 : 1ω7c/C16 : 1ω6c (31.8 %) and iso-C17 : 0 3-OH (23.3 %).The major polar lipids of the novel isolate include phosphatidylethanolamine, three unknown phospholipids (PL1-3) and six unknown lipids (L1-6), and the predominant menaquinone is MK-7. The DNA G+C content is 41.7 mol%. Analysis of 16S rRNA gene sequences revealed that the novel isolate shared the greatest sequence similarity with Sphingobacterium hotanense XH4T (93.50 %). On the basis of phenotypic and genotypic characteristics, strain 7Y-4T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium populi is proposed. The type strain is 7Y-4T (=CFCC 11742T=KCTC 42247T).


Asunto(s)
Filogenia , Populus/microbiología , Sphingobacterium/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfolípidos/química , Corteza de la Planta/microbiología , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Sphingobacterium/genética , Sphingobacterium/aislamiento & purificación , Vitamina K 2/análogos & derivados , Vitamina K 2/química
18.
RNA Biol ; 13(2): 152-6, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26574793

RESUMEN

Repetitive Extragenic Palindromic (REP) sequences are highly conserved, structured, 35- to 40-nt elements located at ∼500 positions around the Escherichia coli chromosome. They are found in intergenic regions and are transcribed together with their upstream genes. Although their stable stem-loop structures protect messages against exoribonuclease digestion, their primary function has remained unknown. Recently, we found that about half of all REP sequences have the potential to stall ribosomes immediately upstream of the termination codon, leading to endonucleolytic cleavage of the mRNA, and induction of the trans-translation process. As a consequence, the mRNA and almost completed protein are degraded, and protein production from the affected gene is down-regulated. The process is critically dependent on the location of the REP element, with an effect only if it is within 15 nt of the termination codon. Using nrdAB as a model, we found that its down-regulation is affected by RNA helicases. Elimination of 6 helicases lowered NrdA production further, whereas overexpression of any RNA helicase partially reversed the downregulation. UV stress completely reversed down-regulation of NrdA production. Analysis of genes containing a REP sequence within 15 nt of the termination codon revealed that most, if not all, are up-regulated by environmental stress, as are RNA helicases. Based on these findings, we propose that REP-dependent downregulation serves as a mechanism to allow a rapid response to environmental stresses whereby RNA helicases partially open the REP elements enabling ribosomes to complete translation immediately increasing protein production from the affected genes.


Asunto(s)
Proteínas de Escherichia coli/genética , Secuencias Invertidas Repetidas/genética , Biosíntesis de Proteínas , ARN Mensajero/genética , Ribonucleósido Difosfato Reductasa/genética , Escherichia coli/genética , Proteínas de Escherichia coli/biosíntesis , Regulación de la Expresión Génica/efectos de la radiación , Interacción Gen-Ambiente , ARN Helicasas/genética , Ribonucleósido Difosfato Reductasa/biosíntesis , Ribosomas/genética , Estrés Fisiológico/genética , Rayos Ultravioleta
19.
Plant Dis ; 100(12): 2394-2401, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30686168

RESUMEN

Valsa canker, caused by Valsa mali, is a destructive disease of apple in China. The pathogen infects apple branches, mainly through pruning wounds, and causes branch and tree death. To determine the conditions required for V. mali infection through pruning wounds and growth within the xylem, pruning wounds on 1- to 4-year-old apple branches were inoculated with conidia in vitro under artificially controlled conditions and in vivo in the orchard. The effects of temperature, wetness duration, and wound age on conidial infection through pruning wounds as well as hyphal growth in the xylem were examined. The results showed that, after invading through pruning wounds, V. mali hyphae grew along xylem vessels, tracheids, and rays, expanding longitudinally and laterally. The hyphae could enter adjacent xylem vessels and tracheids through micropores to form a dense hyphal network. Wetness duration did not exhibit an essential effect on conidial infection from pruning wounds. Conidia spread to pruning wounds with rainwater could infect the xylem without any other extra moisture. Temperature for V. mali conidia infection through pruning wounds and hyphal extension in the xylem ranged from 5 to 35°C, with the optimum at 20°C. Pruning wounds made in late March were susceptible to V. mali infection in March, April, and May; the susceptibility was markedly deceased by June, and the pathogen could barely infect through the pruning wounds in November. The infected pruning wounds began to show symptoms from the spring of the following year. More than half of the observed Valsa canker lesions emerged in the spring of the second year, and new canker twigs were also developed from the inoculations in the spring of the third year. March, April, and May are the critical periods for protecting pruning wounds against infection by V. mali in China, and coating pruning wounds with protective film immediately after pruning is an easy and effective measure to protect the pruning wounds.

20.
Int J Syst Evol Microbiol ; 65(Pt 2): 432-437, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25385993

RESUMEN

Five Gran-stain-negative, facultatively anaerobic, motile, bacterial strains were isolated from symptomatic bark tissue of Populus×euramericana canker. Strains grew at 4-41 °C, pH 4-10 and 0-6 % (w/v) salinity. They were positive with respect to catalase activity and negative for oxidase activity, nitrate reduction and the Voges-Proskauer reaction. Analysis of 16S rRNA gene sequences indicated that these five poplar isolates belong to the genus Brenneria, having highest sequence similarity of 95.98 % with Brenneria goodwinii LMG 26270(T). These five isolates formed a single cluster based on multilocus sequence analysis, indicating that they all belong to a single taxon within the genus Brenneria, which was confirmed by DNA-DNA hybridization. The DNA G+C content was 54.9-55.7 mol%, and the main fatty acids were C16 : 0, C18 : 1ω7c, C17 : 0 cyclo and C16 : 1ω7c/iso-C15 : 0 2-OH. Based on these results, we describe a novel species of the genus Brenneria with the proposed name Brenneria populi sp. nov. The type strain is D9-5(T) ( = CFCC 11963(T) = KCTC 42088(T)).


Asunto(s)
Enterobacteriaceae/clasificación , Filogenia , Corteza de la Planta/microbiología , Populus/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Ácidos Grasos/química , Genes Bacterianos , Datos de Secuencia Molecular , Tipificación de Secuencias Multilocus , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , España
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