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1.
BMC Plant Biol ; 21(1): 360, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362300

RESUMO

BACKGROUND: Dendrobium catenatum belongs to the Orchidaceae, and is a precious Chinese herbal medicine. In the past 20 years, D. catenatum industry has developed from an endangered medicinal plant to multi-billion dollar grade industry. The necrotrophic pathogen Sclerotium delphinii has a devastating effection on over 500 plant species, especially resulting in widespread infection and severe yield loss in the process of large-scale cultivation of D. catenatum. It has been widely reported that Jasmonate (JA) is involved in plant immunity to pathogens, but the mechanisms of JA-induced plant resistance to S. delphinii are unclear. RESULTS: In the present study, the role of JA in enhancing D. catenatum resistance to S. delphinii was investigated. We identified 2 COI1, 13 JAZ, and 12 MYC proteins in D. catenatum genome. Subsequently, systematic analyses containing phylogenetic relationship, gene structure, protein domain, and motif architecture of core JA pathway proteins were conducted in D. catenatum and the newly characterized homologs from its closely related orchid species Phalaenopsis equestris and Apostasia shenzhenica, along with the well-investigated homologs from Arabidopsis thaliana and Oryza sativa. Public RNA-seq data were investigated to analyze the expression patterns of D. catenatum core JA pathway genes in various tissues and organs. Transcriptome analysis of MeJA and S. delphinii treatment showed exogenous MeJA changed most of the expression of the above genes, and several key members, including DcJAZ1/2/5 and DcMYC2b, are involved in enhancing defense ability to S. delphinii in D. catenatum. CONCLUSIONS: The findings indicate exogenous MeJA treatment affects the expression level of DcJAZ1/2/5 and DcMYC2b, thereby enhancing D. catenatum resistance to S. delphinii. This research would be helpful for future functional identification of core JA pathway genes involved in breeding for disease resistance in D. catenatum.


Assuntos
Basidiomycota/patogenicidade , Ciclopentanos/metabolismo , Dendrobium/microbiologia , Oxilipinas/metabolismo , Imunidade Vegetal/fisiologia , Proteínas de Plantas/genética , Acetatos/farmacologia , Ciclopentanos/farmacologia , Dendrobium/efeitos dos fármacos , Dendrobium/imunologia , Dendrobium/metabolismo , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Família Multigênica , Oxilipinas/farmacologia , Filogenia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/imunologia , Transdução de Sinais/genética
2.
Plant Sci ; 310: 110973, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34315591

RESUMO

TaLHY is an MYB transcription factor (TF) that is upregulated by salicylic acid induction and shows circadian rhythms. However, the study of the upstream regulatory factors is still unclear. In this study, we cloned the promoter sequence of the TaLHY homologous genes, verified the activity of the promoters, and identified important regions that affect promoter activity. Furthermore, we explored a possible upstream regulator of TaLHY, named TaWRKY10, which played a key role in the expression of TaLHY. We found that the three promoters pTaLHYa, pTaLHYb, and pTaLHYd had transcriptional activity in wheat protoplasts. All three promoters have W-Box, which can bind to WRKY TFs. Using virus-induced gene silencing (VIGS), after silencing TaWRKY10, the resistance of ChuanNong 19 (CN19) to stripe rust pathogen strain CYR32 was lost, and the expression level of the TaLHY homologous gene decreased. At the same time, in wheat protoplasts, the transcriptional activity of TaLHY homologous promoters improved after TaWRKY10 overexpression. This indicates that TaWRKY10 is a key gene for wheat immune response to stripe rust, and this gene may bind to TaLHYa, TaLHYb, and TaLHYd promoters to regulate the expression of TaLHY.


Assuntos
Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Triticum/metabolismo , Basidiomycota/patogenicidade , Resistência à Doença/genética , Resistência à Doença/fisiologia , Doenças das Plantas/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Triticum/genética
3.
PLoS Pathog ; 17(6): e1009641, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34166468

RESUMO

Biotrophic plant pathogens secrete effector proteins to manipulate the host physiology. Effectors suppress defenses and induce an environment favorable to disease development. Sequence-based prediction of effector function is impeded by their rapid evolution rate. In the maize pathogen Ustilago maydis, effector-coding genes frequently organize in clusters. Here we describe the functional characterization of the pleiades, a cluster of ten effector genes, by analyzing the micro- and macroscopic phenotype of the cluster deletion and expressing these proteins in planta. Deletion of the pleiades leads to strongly impaired virulence and accumulation of reactive oxygen species (ROS) in infected tissue. Eight of the Pleiades suppress the production of ROS upon perception of pathogen associated molecular patterns (PAMPs). Although functionally redundant, the Pleiades target different host components. The paralogs Taygeta1 and Merope1 suppress ROS production in either the cytoplasm or nucleus, respectively. Merope1 targets and promotes the auto-ubiquitination activity of RFI2, a conserved family of E3 ligases that regulates the production of PAMP-triggered ROS burst in plants.


Assuntos
Basidiomycota/fisiologia , Basidiomycota/patogenicidade , Proteínas Fúngicas/metabolismo , Doenças das Plantas/imunologia , Imunidade Vegetal/imunologia , Proteínas Fúngicas/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Virulência/fisiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
4.
PLoS One ; 16(5): e0243675, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33999918

RESUMO

Durum wheat is an important cereal grown in Ethiopia, a country which is also its center for genetic diversity. Yellow (stripe) rust caused by Puccinia striiformis fsp tritici is one of the most devastating diseases threatening Ethiopian wheat production. To identify sources of genetic resistance and combat this pathogen, we conducted a genome wide association study of yellow rust resistance on 300 durum wheat accessions comprising 261 landraces and 39 cultivars. The accessions were evaluated for their field resistance using a modified Cobb scale at Meraro, Kulumsa and Chefe Donsa in the 2015 and 2016 main growing seasons. Analysis of the 35K Axiom Array genotyping data of the panel resulted in a total of 8,797 polymorphic SNPs of which 7,093 were used in subsequent analyses. Population structure analysis suggested two groups in which the cultivars clearly stood out separately from the landraces. Eleven SNPs significantly associated with yellow rust resistance were identified on four chromosomes (1A, 1B, 2B, and 5A) which defined at least five genomic loci. Six of the SNPs were consistently identified on chromosome 1B singly at each and combined overall environments which explained 62.6-64.0% of the phenotypic variation (R2). Resistant allele frequency ranged from 14.0-71.0%; Zooming in to the identified resistance loci revealed the presence of disease resistance related genes involved in the plant defense system such as the ABC transporter gene family, disease resistance protein RPM1 (NBS-LRR class), Receptor kinases and Protein kinases. This study has provided SNPs for tracking the loci associated with yellow rust resistance and a diversity panel which can be used for association study of other agriculturally important traits in durum wheat.


Assuntos
Resistência à Doença/genética , Estudo de Associação Genômica Ampla , Doenças das Plantas/genética , Triticum/genética , Basidiomycota/genética , Basidiomycota/patogenicidade , Mapeamento Cromossômico , Frequência do Gene/genética , Genoma de Planta/genética , Genótipo , Desequilíbrio de Ligação/genética , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética
5.
Nat Microbiol ; 6(6): 722-730, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33941900

RESUMO

Plant pathogenic fungi colonizing living plant tissue secrete a cocktail of effector proteins to suppress plant immunity and reprogramme host cells. Although many of these effectors function inside host cells, delivery systems used by pathogenic bacteria to translocate effectors into host cells have not been detected in fungi. Here, we show that five unrelated effectors and two membrane proteins from Ustilago maydis, a biotrophic fungus causing smut disease in corn, form a stable protein complex. All seven genes appear co-regulated and are only expressed during colonization. Single mutants arrest in the epidermal layer, fail to suppress host defence responses and fail to induce non-host resistance, two reactions that likely depend on translocated effectors. The complex is anchored in the fungal membrane, protrudes into host cells and likely contacts channel-forming plant plasma membrane proteins. Constitutive expression of all seven complex members resulted in a surface-exposed form in cultured U. maydis cells. As orthologues of the complex-forming proteins are conserved in smut fungi, the complex may become an interesting fungicide target.


Assuntos
Basidiomycota/metabolismo , Basidiomycota/patogenicidade , Proteínas Fúngicas/metabolismo , Doenças das Plantas/microbiologia , Basidiomycota/genética , Basidiomycota/crescimento & desenvolvimento , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Virulência , Zea mays/microbiologia
6.
J Appl Genet ; 62(3): 431-439, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33990930

RESUMO

Triticale (× Triticosecale Wittmack) is a commercial hybrid harboring wheat (Triticum sp.) and rye (Secale cereale L.) genomes. The limited genetic diversity of this crop resulted in the collapse of fungal disease resistance. Leaf rust disease, caused by Puccinia triticina Eriks., is reported to reduce the triticale yield significantly (more than 30%). There is a need to enlarge the genetic variability of this crop including leaf resistance genes. The main aim of this research was to evaluate the leaf rust resistance of the offspring of translocation lines of triticale carrying chromatin of Ae. tauschii and Ae. kotschyi. A reaction of seedlings of 200 plants of two triticale-Aegilops translocation lines (Bogo-2Dt.2R and Sekundo-2Sk.2R) was compared after inoculation with a natural mixture of P. triticina races, specific to triticale in controlled condition. Before inoculation, each plant was screened using molecular cytogenetics and molecular markers linked to leaf rust resistance genes. The presence of Aegilops chromosome segments was confirmed using genomic in situ hybridization (GISH). Lr39 and Lr54 leaf rust resistance genes were identified using Xgdm35 and S14 molecular markers, respectively. After inoculation, a significant improvement of resistance severity was observed in Sekundo-2Sk.2R in comparison with triticale cv. Sekundo plants. The resistance level of Bogo-2Dt.2R did not differ compared with triticale cv. Bogo plants. It was shown that Lr39 gene did not increase the leaf rust resistance level of triticale cv. Bogo.


Assuntos
Aegilops , Basidiomycota , Resistência à Doença/genética , Doenças das Plantas/genética , Triticale , Aegilops/genética , Basidiomycota/patogenicidade , Cromossomos de Plantas , Genes de Plantas , Doenças das Plantas/microbiologia , Triticale/genética , Triticale/microbiologia
7.
BMC Plant Biol ; 21(1): 215, 2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-33985437

RESUMO

BACKGROUND: Ginseng rusty root symptoms (GRS) is one of the primary diseases of ginseng. This disease leads to a severe decline in the quality of ginseng. It has been shown that the occurrence of GRS is associated with soil environmental degradation, which may involve changes in soil microbiology and physicochemical properties. RESULTS: In this study, GRS and healthy ginseng (HG) samples were used as experimental materials for comparative analysis of transcriptome and metabolome. Compared with those in HG samples, 949 metabolites and 9451 genes were significantly changed at the metabolic and transcriptional levels in diseased samples. The diseased tissues' metabolic patterns changed, and the accumulation of various organic acids, alkaloids, alcohols and phenols in diseased tissues increased significantly. There were significant differences in the expression of genes involved in plant hormone signal transduction, phenylpropanoid biosynthesis, the peroxidase pathway, and the plant-pathogen interaction pathway. CONCLUSION: The current study involved a comparative metabolome and transcriptome analysis of GRS and HG samples. Based on the findings at the transcriptional and metabolic levels, a mechanism model of the ginseng response to GRS was established. Our results provide new insights into ginseng's response to GRS, which will reveal the potential molecular mechanisms of this disease in ginseng.


Assuntos
Basidiomycota/patogenicidade , Resistência à Doença/genética , Panax/genética , Panax/imunologia , Panax/microbiologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , China , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Metaboloma , Raízes de Plantas/microbiologia , Plantas Medicinais/genética , Plantas Medicinais/microbiologia
8.
Evolution ; 75(6): 1450-1465, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33914360

RESUMO

Organisms are constantly challenged by pathogens and pests, which can drive the evolution of growth-defense strategies. Plant stomata are essential for gas exchange during photosynthesis and conceptually lie at the intersection of the physiological demands of growth and exposure to foliar fungal pathogens. Generations of natural selection for locally adapted growth-defense strategies can eliminate variation between traits, potentially masking trade-offs and selection conflicts that may have existed in the past. Hybrid populations offer a unique opportunity to reset the clock on selection and to study potentially maladaptive trait variation before selection removes it. We study the interactions of growth, stomatal, ecopysiological, and disease resistance traits in poplars (Populus) after infection by the leaf rust Melampsora medusae. Phenotypes were measured in a common garden and genotyped at 227K SNPs. We isolate the effects of hybridization on trait variance, discover correlations between stomatal, ecophysiology, and disease resistance, examine trade-offs and selection conflicts, and explore the evolution of growth-defense strategies potentially mediated by selection for stomatal traits on the upper leaf surface. These results suggest an important role for stomata in determining growth-defense strategies in organisms susceptible to foliar pathogens, and reinforces the contribution of hybridization studies toward our understanding of trait evolution.


Assuntos
Resistência à Doença/genética , Hibridização Genética , Estômatos de Plantas/fisiologia , Populus/genética , Adaptação Fisiológica , Basidiomycota/patogenicidade , Genética Populacional , América do Norte , Fenótipo , Doenças das Plantas/microbiologia , Populus/microbiologia
9.
Theor Appl Genet ; 134(7): 2197-2211, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33791822

RESUMO

Key message The stripe rust resistance gene Yr34 was transferred to polyploid wheat chromosome 5AL from T. monococcum and has been used for over two centuries.Wheat stripe (or yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is currently among the most damaging fungal diseases of wheat worldwide. In this study, we report that the stripe rust resistance gene Yr34 (synonym Yr48) is located within a distal segment of the cultivated Triticum monococcum subsp. monococcum chromosome 5AmL translocated to chromosome 5AL in polyploid wheat. The diploid wheat species Triticum monococcum (genome AmAm) is closely related to T. urartu (donor of the A genome to polyploid wheat) and has good levels of resistance against the stripe rust pathogen. When present in hexaploid wheat, the T. monococcum Yr34 resistance gene confers a moderate level of resistance against virulent Pst races present in California and the virulent Chinese race CYR34. In a survey of 1,442 common wheat genotypes, we identified 5AmL translocations of fourteen different lengths in 17.5% of the accessions, with higher frequencies in Europe than in other continents. The old European wheat variety "Mediterranean" was identified as a putative source of this translocation, suggesting that Yr34 has been used for over 200 years. Finally, we designed diagnostic CAPS and sequenced-based markers that will be useful to accelerate the deployment of Yr34 in wheat breeding programs to improve resistance to this devastating pathogen.


Assuntos
Basidiomycota/patogenicidade , Resistência à Doença/genética , Doenças das Plantas/genética , Triticum/genética , Mapeamento Cromossômico , Genes de Plantas , Marcadores Genéticos , Genótipo , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Poliploidia , Recombinação Genética , Triticum/microbiologia
10.
Theor Appl Genet ; 134(7): 2291-2301, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33837443

RESUMO

KEY MESSAGE: Discovery of two rust resistance genes, R17 and R18, from the sunflower lines introduced from South Africa and genetic mapping of them to sunflower chromosome 13. Rust, caused by the fungus Puccinia helianthi Schw., is one of the most serious diseases of sunflower in the world. The rapid changes that occur in the virulence characteristics of pathogen populations present a continuous threat to the effectiveness of existing rust-resistant hybrids. Thus, there is a continued need for the characterization of genetically diverse sources of rust resistance. In this study, we report to identify two new rust resistance genes, R17 and R18, from the sunflower lines, KP193 and KP199, introduced from South Africa. The inheritance of rust resistance was investigated in both lines using two mapping populations developed by crossing the resistant plants selected from KP193 and KP199 with a common susceptible parent HA 89. The F2 populations were first genotyped using genotyping by sequencing for mapping of the rust genes and further saturated with markers in the target region. Molecular mapping positioned the two genes at the lower end of sunflower chromosome 13 within a large gene cluster. Two co-segregating SNP markers, SFW01497 and SFW08875, were distal to R17 at a 1.9 cM genetic distance, and a cluster of five co-segregating SNPs was proximal to R17 at 0.7 cM. R18 co-segregated with the SNP marker SFW04317 and was proximal to two cosegregating SNPs, SFW01497 and SFW05453, at 1.9 cM. These maps provide markers for stacking R17 or R18 with other broadly effective rust resistance genes to extend the durability of rust resistance. The relationship of the six rust resistance genes in the cluster was discussed.


Assuntos
Basidiomycota/patogenicidade , Resistência à Doença/genética , Helianthus/genética , Doenças das Plantas/genética , Mapeamento Cromossômico , Genes de Plantas , Ligação Genética , Marcadores Genéticos , Genótipo , Helianthus/microbiologia , Família Multigênica , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , África do Sul
11.
Theor Appl Genet ; 134(7): 2213-2220, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33839800

RESUMO

KEY MESSAGE: An adult plant stripe rust resistance gene Yr75 was located on the long arm of chromosome 7A. Fine mapping of the region identified markers closely linked with Yr75. Australian wheat cultivar Axe produced resistant to moderately resistant stripe rust responses under field conditions and was exhibiting seedling responses varying from 33C to 3+ under greenhouse conditions. Experiments covering tests at different growth stages (2nd, 3rd and 4th leaf stages) demonstrated the clear expression of resistance at the 4th leaf stage under controlled-environment greenhouse conditions. A recombinant inbred line (RIL) population was developed from the Axe/Nyabing-3 (Nyb) cross. Genetic analysis of Axe/Nyb RIL population in the greenhouse at the 4th leaf stage showed monogenic inheritance of stripe rust resistance. Selective genotyping using the iSelect 90 K Infinium SNP genotyping array was performed, and the resistance locus was mapped to the long arm of chromosome 7A and named Yr75. The Axe/Nyb RIL population was genotyped using a targeted genotype-by-sequencing assay, and the resistance-linked SNPs were converted into kompetitive allele-specific PCR (KASP) markers. These markers were tested on the entire Axe/Nyb RIL population, and markers sunKASP_430 and sunKASP_427 showed close association with Yr75 in the Axe/Nyb RIL population. A high-resolution mapping family of 1032 F2 plants from the Axe/Nyb cross was developed and genotyped with sunKASP_430 and sunKASP_427, and these markers flanked Yr75 at 0.3 cM and 0.4 cM, respectively. These markers cover 1.24 Mb of the physical map of Chinese Spring, and this information will be useful for map-based cloning of Yr75.


Assuntos
Basidiomycota/patogenicidade , Resistência à Doença/genética , Doenças das Plantas/genética , Triticum/genética , Austrália , Mapeamento Cromossômico , Genes de Plantas , Genótipo , Fenótipo , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Triticum/microbiologia
12.
Genes (Basel) ; 12(3)2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809560

RESUMO

Tilletia controversa J. G. Kühn is a causal organism of dwarf bunt in wheat. Understanding the interaction of wheat and T. controversa is of practical and scientific importance for disease control. In this study, the relative expression of TaLHY and TaPR-4 and TaPR-5 genes was higher in a resistant (Yinong 18) and moderately resistant (Pin 9928) cultivars rather than susceptible (Dongxuan 3) cultivar at 72 h post inoculation (hpi) with T. controversa. Similarly, the expression of defensin, TaPR-2 and TaPR-10 genes was observed higher in resistant and moderately resistant cultivars after exogenous application of phytohormones, including methyl jasmonate, salicylic acid, and abscisic acid. Laser confocal microscopy was used to track the fungal hyphae in the roots, leaves, and tapetum cells, which of susceptible cultivar were infected harshly by T. controversa than moderately resistant and resistant cultivars. There were no fungal hyphae in tapetum cells in susceptible cultivar after methyl jasmonate, salicylic acid and abscisic acid treatments. Moreover, after T. controversa infection, the pollen germination was of 80.06, 58.73, and 0.67% in resistant, moderately resistant and susceptible cultivars, respectively. The above results suggested that the use using of resistant cultivar is a good option against the dwarf bunt disease.


Assuntos
Basidiomycota/patogenicidade , Triticum/genética , Triticum/microbiologia , Ácido Abscísico/farmacologia , Acetatos/farmacologia , Ciclopentanos/farmacologia , Resistência à Doença/genética , Microscopia Confocal/métodos , Oxilipinas/farmacologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/microbiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Ácido Salicílico/farmacologia , Triticum/efeitos dos fármacos
13.
Molecules ; 26(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920885

RESUMO

Dietary intervention in type 2 diabetes mellitus (T2DM) is a hotspot in international research because of potential threats to human health. Phellinus baumii, a wild fungus traditionally used as a food and medicine source, is now cultivated in certain East Asian countries, and is rich in polyphenols, which are effective anti-inflammatory ingredients useful in treatment of T2DM, with fewer side effects than drugs. To examine the hypoglycaemic effects of Phellinus baumii phenolics (PPE), the metabolite profiles of T2DM mice induced by streptozotocin after PPE intervention were systematically analyzed. Here, 10 normal mice were given normal saline as control group, and 50 model mice were randomly assigned to five groups and daily intragastric administrated with saline, metformin (100 mg/kg), and PPE (50, 100, 150 mg/kg of body weight), for 60 days. The pro-inflammatory factor contents of lipopolysaccharide stimulation of RAW 264.7 cells were decreased in a dose-dependent manner after PPE treatment, we propose that PPE could exert anti-inflammatory properties. PPE could also effectively reduce blood glucose levels, increased insulin sensitivity, and improved other glucolipid metabolism. Q-PCR results suggested that the hypoglycemic effects of PPE might be through activating IRS1/PI3K/AKT pathway in diabetic mice. These results suggest that PPE has strong potential as dietary components in the prevention or management of T2DM.


Assuntos
Phellinus/química , Fenóis/uso terapêutico , Animais , Basidiomycota/efeitos dos fármacos , Basidiomycota/patogenicidade , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Hipoglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Lipopolissacarídeos/fisiologia , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Reação em Cadeia da Polimerase , Células RAW 264.7
14.
mBio ; 12(2)2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653886

RESUMO

The biotrophic fungus Ustilago maydis harbors a chitin deacetylase (CDA) family of six active genes as well as one pseudogene which are differentially expressed during colonization. This includes one secreted soluble CDA (Cda4) and five putatively glycosylphosphatidylinositol (GPI)-anchored CDAs, of which Cda7 belongs to a new class of fungal CDAs. Here, we provide a comprehensive functional study of the entire family. While budding cells of U. maydis showed a discrete pattern of chitosan staining, biotrophic hyphae appeared surrounded by a chitosan layer. We purified all six active CDAs and show their activity on different chitin substrates. Single as well as multiple cda mutants were generated and revealed a virulence defect for mutants lacking cda7 We implicated cda4 in production of the chitosan layer surrounding biotrophic hyphae and demonstrated that the loss of this layer does not reduce virulence. By combining different cda mutations, we detected redundancy as well as specific functions for certain CDAs. Specifically, certain combinations of mutations significantly affected virulence concomitantly with reduced adherence, appressorium formation, penetration, and activation of plant defenses. Attempts to inactivate all seven cda genes simultaneously were unsuccessful, and induced depletion of cda2 in a background lacking the other six cda genes illustrated an essential role of chitosan for cell wall integrity.IMPORTANCE The basidiomycete Ustilago maydis causes smut disease in maize, causing substantial losses in world corn production. This nonobligate pathogen penetrates the plant cell wall with the help of appressoria and then establishes an extensive biotrophic interaction, where the hyphae are tightly encased by the plant plasma membrane. For successful invasion and development in plant tissue, recognition of conserved fungal cell wall components such as chitin by the plant immune system needs to be avoided or suppressed. One strategy to achieve this lies in the modification of chitin to chitosan by chitin deacetylases (CDAs). U. maydis has seven cda genes. This study reveals discrete as well as redundant contributions of these genes to virulence as well as to cell wall integrity. Unexpectedly, the inactivation of all seven genes is not tolerated, revealing an essential role of chitosan for viability.


Assuntos
Amidoidrolases/genética , Basidiomycota/genética , Basidiomycota/patogenicidade , Quitina/metabolismo , Quitosana/metabolismo , Interações Hospedeiro-Patógeno , Fatores de Virulência/genética , Amidoidrolases/classificação , Amidoidrolases/metabolismo , Basidiomycota/enzimologia , Regulação Fúngica da Expressão Gênica , Doenças das Plantas/microbiologia , Virulência , Zea mays/microbiologia
15.
Theor Appl Genet ; 134(7): 2005-2021, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33683400

RESUMO

KEY MESSAGE: A large genomic region spanning over 300 Mb on chromosome 6A under intense artificial selection harbors multiple loci associated with favorable traits including stripe rust resistance in wheat. The development of resistance cultivars can be an optimal strategy for controlling wheat stripe rust disease. Although loci for stripe rust resistance have been identified on chromosome 6A in previous studies, it is unclear whether these loci span a common genetic interval, and few studies have attempted to analyze the haplotype changes that have accompanied wheat improvement over the period of modern breeding. In this study, we used F2:3 families and F6:7 recombinant inbred lines (RILs) derived from a cross between a resistant CIMMYT wheat accession P10090 and the susceptible landrace Mingxian 169 to improve the resolution of the QTL on chromosome 6A. The co-located QTL, designated as YrP10090, was flanked by SNP markers AX-94460938 and AX-110585473 with a genetic interval of 3.5 cM, however, corresponding to a large physical distance of over 300 Mb in RefSeq v.1.0 (positions 107.1-446.5 Mb). More than 1,300 SNP markers in this genetic region were extracted for haplotype analysis in a panel of 1,461 worldwide common wheat accessions, and three major haplotypes (Hap1, Hap2, and Hap3) were identified. The favorable haplotype Hap1 associated with stripe rust resistance exhibited a large degree of linkage disequilibrium. Selective sweep analyses were performed between different haplotype groups, revealing specific genomic regions with strong artificial selection signals. These regions harbored multiple desirable traits associated with resilience to environmental stress, different yield components, and quality characteristics. P10090 and its derivatives that carry the desirable haplotype can provide a concrete foundation for bread wheat improvement including the genomic selection.


Assuntos
Basidiomycota/patogenicidade , Resistência à Doença/genética , Haplótipos , Doenças das Plantas/genética , Triticum/genética , Mapeamento Cromossômico , Ligação Genética , Desequilíbrio de Ligação , Fenótipo , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Triticum/microbiologia
16.
Theor Appl Genet ; 134(7): 1989-2003, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33688982

RESUMO

KEY MESSAGE: Individual stem rust resistance genes could be directly mapped within self-incompatible rye populations. Genetic resources of rye (Secale cereale L.) are cross-pollinating populations that can be highly diverse and are naturally segregating. In this study, we show that this segregation could be used for mapping stem rust resistance. Populations of pre-selected donors from the Russian Federation, the USA and Austria were tested on a single-plant basis for stem rust resistance by a leaf-segment test with three rust isolates. Seventy-four plants per population were genotyped with a 10 K-SNP chip. Using cumulative logit models, significant associations between the ordinal infection score and the marker alleles could be found. Three different loci (Pgs1, Pgs2, Pgs3) in three populations were highly significant, and resistance-linked markers could be validated with field experiments of an independent seed sample from the original population and were used to fix two populations for resistance. We showed that it is possible to map monogenically inherited seedling resistance genes directly in genetic resources, thus providing a competitive alternative to linkage mapping approaches that require a tedious and time-consuming inbreeding over several generations.


Assuntos
Basidiomycota/patogenicidade , Mapeamento Cromossômico , Resistência à Doença/genética , Doenças das Plantas/genética , Secale/genética , Alelos , Ligação Genética , Genótipo , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Secale/microbiologia
17.
Mil Med Res ; 8(1): 19, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750466

RESUMO

BACKGROUND: Invasive Trichosporon asahii (T. asahii) infection frequently occurs with a high mortality in immunodeficient hosts, but the pathogenesis of T. asahii infection remains elusive. Circular RNAs (circRNAs) are a type of endogenous noncoding RNA that participate in various disease processes. However, the mechanism of circRNAs in T. asahii infection remains completely unknown. METHODS: RNA sequencing (RNA-seq) was performed to analyze the expression profiles of circRNAs, microRNAs (miRNAs), and mRNAs in THP-1 cells infected with T. asahii or uninfected samples. Some of the RNA-seq results were verified by RT-qPCR. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to analyze the differentially expressed mRNAs. A circRNA-miRNA-mRNA network was constructed and verified by dual-luciferase reporter assay and overexpression experiments. RESULTS: A total of 46 circRNAs, 412 mRNAs and 47 miRNAs were differentially expressed at 12 h after T. asahii infection. GO and KEGG analyses showed that the differentially expressed mRNAs were primarily linked to the leukocyte migration involved in the inflammatory response, the Toll-like receptor signaling pathway, and the TNF signaling pathway. A competing endogenous RNA (ceRNA) network was constructed with 5 differentially expressed circRNAs, 5 differentially expressed miRNAs and 42 differentially expressed mRNAs. Among them, hsa_circ_0065336 was found to indirectly regulate PTPN11 expression by sponging miR-505-3p. CONCLUSIONS: These data revealed a comprehensive circRNA-associated ceRNA network during T. asahii infection, thus providing new insights into the pathogenesis of the T. asahii-host interactions.


Assuntos
Basidiomycota/efeitos dos fármacos , MicroRNAs/farmacologia , RNA Circular/farmacologia , RNA Mensageiro/farmacologia , Tricosporonose/terapia , Basidiomycota/patogenicidade , Humanos , MicroRNAs/uso terapêutico , RNA Circular/uso terapêutico , RNA Mensageiro/uso terapêutico , Transdução de Sinais/efeitos dos fármacos
18.
Dokl Biol Sci ; 496(1): 13-16, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33635483

RESUMO

Monopustule isolates of wheat, oats and barley rust pathogens reproduced under different environmental conditions were used to infect experimental samples of these crops. Differences in the types of reactions after infection of one plant genotype with one pathogen genotype reproduced at different temperatures, as well as in the presence of potassium chloride, ammonium nitrate and maleic acid hydrazide indicate the impossibility of explaining the phenomena of plant-pathogen interaction within the framework of Flor's classical gene-for-gene theory. Each gene of the host resistance corresponds to several complementary virulence genes, or to several different alleles of one same gene for virulence.


Assuntos
Basidiomycota/genética , Grão Comestível/genética , Doenças das Plantas/genética , Triticum/genética , Basidiomycota/patogenicidade , Resistência à Doença , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/microbiologia , Genótipo , Hordeum/genética , Hordeum/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Triticum/crescimento & desenvolvimento , Triticum/microbiologia
19.
J Mycol Med ; 31(2): 101123, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33639444

RESUMO

Papiliotrema laurentii (formerly Cryptococcus laurentii) and Papiliotrema albidus (formerly Cryptococcus albidus) are yeast-like environmental fungi which are largely considered as non-pathogenic to humans. However, invasive infections caused by P. laurentii have recently been reported in some patients with an impaired immune system. Here, we describe the first case of P. laurentii fungemia in a premature, very low-birth-weight neonate in Kuwait and the Middle East. Repeated bloodstream isolates were obtained and were tentatively identified as P. laurentii by Vitek 2 yeast identification system. The identification of the yeast isolates as P. laurentii was confirmed by PCR-sequencing of ribosomal DNA (rDNA). Antifungal susceptibility testing data showed that the isolates were susceptible to amphotericin B, fluconazole and voriconazole but appeared resistant to caspofungin. The baby was successfully treated with liposomal amphotericin B.


Assuntos
Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Basidiomycota/efeitos dos fármacos , Basidiomycota/genética , Fungemia/diagnóstico , Fungemia/tratamento farmacológico , Adulto , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Basidiomycota/classificação , Basidiomycota/patogenicidade , DNA Ribossômico/genética , Feminino , Fungemia/microbiologia , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Kuweit , Masculino , Técnicas de Tipagem Micológica , Resultado do Tratamento
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