scholarly journals Small RNA inhibits infection by downy mildew pathogen Hyaloperonospora arabidopsidis

2019 ◽  
Vol 20 (11) ◽  
pp. 1523-1534 ◽  
Author(s):  
Özlem Bilir ◽  
Osman Telli ◽  
Chris Norman ◽  
Hikmet Budak ◽  
Yiguo Hong ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Small Rna ◽  
Hyaloperonospora Arabidopsidis

scholarly journals Nontoxic Nep1-Like Proteins of the Downy Mildew Pathogen Hyaloperonospora arabidopsidis: Repression of Necrosis-Inducing Activity by a Surface-Exposed Region

2012 ◽  
Vol 25 (5) ◽  
pp. 697-708 ◽  
Author(s):  
Adriana Cabral ◽  
Stan Oome ◽  
Nick Sander ◽  
Isabell Küfner ◽  
Thorsten Nürnberger ◽  
...  
Keyword(s):  
Amino Acids ◽  
Downy Mildew ◽  
Plant Pathogens ◽  
Exposed Region ◽  
Alternative Function ◽  
Early Expression ◽  
Specific Expansion ◽  
Species Specific ◽  
Hyaloperonospora Arabidopsidis ◽  
Specific Cluster

The genome of the downy mildew pathogen Hyaloperonospora arabidopsidis encodes necrosis and ethylene-inducing peptide 1 (Nep1)-like proteins (NLP). Although NLP are widely distributed in eukaryotic and prokaryotic plant pathogens, it was surprising to find these proteins in the obligate biotrophic oomycete H. arabidopsidis. Therefore, we analyzed the H. arabidopsidis NLP (HaNLP) family and identified 12 HaNLP genes and 15 pseudogenes. Most of the 27 genes form an H. arabidopsidis–specific cluster when compared with other oomycete NLP genes, suggesting this class of effectors has recently expanded in H. arabidopsidis. HaNLP transcripts were mainly detected during early infection stages. Agrobacterium tumefaciens–mediated transient expression and infiltration of recombinant NLP into tobacco and Arabidopsis leaves revealed that all HaNLP tested are noncytotoxic proteins. Even HaNLP3, which is most similar to necrosis-inducing NLP proteins of other oomycetes and which contains all amino acids that are critical for necrosis-inducing activity, did not induce necrosis. Chimeras constructed between HaNLP3 and the necrosis-inducing PsojNIP protein demonstrated that most of the HaNLP3 protein is functionally equivalent to PsojNIP, except for an exposed domain that prevents necrosis induction. The early expression and species-specific expansion of the HaNLP genes is suggestive of an alternative function of noncytolytic NLP proteins during biotrophic infection of plants.

scholarly journals Downy Mildew effector HaRxL21 interacts with the transcriptional repressor TOPLESS to promote pathogen susceptibility

2020 ◽  
Author(s):  
Sarah Harvey ◽  
Priyanka Kumari ◽  
Dmitry Lapin ◽  
Thomas Griebel ◽  
Richard Hickman ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Transcriptional Repression ◽  
Plant Immunity ◽  
Effector Proteins ◽  
Host Susceptibility ◽  
Close Relative ◽  
C Terminus ◽  
Rxlr Effector ◽  
Oomycete Pathogen ◽  
Hyaloperonospora Arabidopsidis

AbstractHyaloperonospora arabidopsidis (Hpa) is an oomycete pathogen causing Arabidopsis downy mildew. Effector proteins secreted from the pathogen into the plant play key roles in promoting infection by suppressing plant immunity and manipulating the host to the pathogen’s advantage. One class of oomycete effectors share a conserved ‘RxLR’ motif critical for their translocation into the host cell. Here we characterize the interaction between an RxLR effector, HaRxL21 (RxL21), and the Arabidopsis transcriptional co-repressor Topless (TPL). We establish that RxL21 and TPL interact via an EAR motif at the C-terminus of the effector, mimicking the host plant mechanism for recruiting TPL to sites of transcriptional repression. We show that this motif, and hence interaction with TPL, is necessary for the virulence function of the effector. Furthermore, we provide evidence that RxL21 uses the interaction with TPL, and its close relative TPL-related 1, to repress plant immunity and enhance host susceptibility to both biotrophic and necrotrophic pathogens.

scholarly journals Analysis of microsatellites from the transcriptome of downy mildew pathogens and their application for characterization of Pseudoperonospora populations

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3266 ◽  
Author(s):  
Emma C. Wallace ◽  
Lina M. Quesada-Ocampo
Keyword(s):  
Downy Mildew ◽  
Draft Genome ◽  
Model Organism ◽  
Genomic Analysis ◽  
Population Level ◽  
Comparative Genomic ◽  
Pathogen Population ◽  
Pseudoperonospora Humuli ◽  
Hyaloperonospora Arabidopsidis

Downy mildew pathogens affect several economically important crops worldwide but, due to their obligate nature, few genetic resources are available for genomic and population analyses. Draft genomes for emergent downy mildew pathogens such as the oomycete Pseudoperonospora cubensis, causal agent of cucurbit downy mildew, have been published and can be used to perform comparative genomic analysis and develop tools such as microsatellites to characterize pathogen population structure. We used bioinformatics to identify 2,738 microsatellites in the P. cubensis predicted transcriptome and evaluate them for transferability to the hop downy mildew pathogen, Pseudoperonospora humuli, since no draft genome is available for this species. We also compared the microsatellite repertoire of P. cubensis to that of the model organism Hyaloperonospora arabidopsidis, which causes downy mildew in Arabidopsis. Although trends in frequency of motif-type were similar, the percentage of SSRs identified from P. cubensis transcripts differed significantly from H. arabidopsidis. The majority of a subset of microsatellites selected for laboratory validation (92%) produced a product in P. cubensis isolates, and 83 microsatellites demonstrated transferability to P. humuli. Eleven microsatellites were found to be polymorphic and consistently amplified in P. cubensis isolates. Analysis of Pseudoperonospora isolates from diverse hosts and locations revealed higher diversity in P. cubensis compared to P. humuli isolates. These microsatellites will be useful in efforts to better understand relationships within Pseudoperonospora species and P. cubensis on a population level.

scholarly journals Decay of Genes Encoding the Oomycete Flagellar Proteome in the Downy Mildew Hyaloperonospora arabidopsidis

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e47624 ◽  
Author(s):  
Howard S. Judelson ◽  
Jolly Shrivastava ◽  
Joseph Manson
Keyword(s):  
Downy Mildew ◽  
Genes Encoding ◽  
Hyaloperonospora Arabidopsidis

scholarly journals Disease-Specific Expression of Host Genes During Downy Mildew Infection of Arabidopsis

2009 ◽  
Vol 22 (9) ◽  
pp. 1104-1115 ◽  
Author(s):  
Robin P. Huibers ◽  
Mark de Jong ◽  
René W. Dekter ◽  
Guido Van den Ackerveken
Keyword(s):  
Downy Mildew ◽  
In Silico Analysis ◽  
Effector Proteins ◽  
Ethylene Response Factor ◽  
Promoter Regions ◽  
Specific Expression ◽  
Transcription Factor Genes ◽  
Responsive Element ◽  
Hyaloperonospora Arabidopsidis ◽  
Incompatible Interactions

Here, we report on the identification of Arabidopsis genes that are induced during compatible but not during incompatible interactions with the downy mildew pathogen Hyaloperonospora arabidopsidis. This set of so-called compatible specific (CS) genes contrasts with the large group of defense-associated genes that is differentially expressed during both compatible and incompatible interactions. From the 17 identified CS genes, 6 belong to the ethylene response factor (ERF) family of transcription factor genes, suggesting that these ERF have a role during compatibility. The majority of CS genes are differentially regulated in response to various forms of abiotic stress. In silico analysis of the CS genes revealed an over-representation of dehydration-responsive element/C-repeat binding factor (DREB1A/CBF3) binding sites and EveningElement motifs in their promoter regions. The CS-ERF are closely related to the CBF transcription factors and could potentially bind the DREB1A/CBF3 promoter elements in the CS genes. Transcript levels of CS genes peak at 2 to 3 days postinoculation, when pathogen growth is highest, and decline at later stages of infection. The induction of several CS genes was found to be isolate specific. This suggests that the identified CS genes could be the direct or indirect targets of downy mildew effector proteins that promote disease susceptibility.

scholarly journals Genome Sequence and Architecture of the Tobacco Downy Mildew Pathogen Peronospora tabacina

2015 ◽  
Vol 28 (11) ◽  
pp. 1198-1215 ◽  
Author(s):  
Lida Derevnina ◽  
Sebastian Chin-Wo-Reyes ◽  
Frank Martin ◽  
Kelsey Wood ◽  
Lutz Froenicke ◽  
...  
Keyword(s):  
Downy Mildew ◽  
De Novo ◽  
Nuclear Genome ◽  
Peronospora Tabacina ◽  
Protein Coding ◽  
Rxlr Effectors ◽  
Intergenic Regions ◽  
High Level ◽  
Genomic Regions ◽  
Hyaloperonospora Arabidopsidis

Peronospora tabacina is an obligate biotrophic oomycete that causes blue mold or downy mildew on tobacco (Nicotiana tabacum). It is an economically important disease occurring frequently in tobacco-growing regions worldwide. We sequenced and characterized the genomes of two P. tabacina isolates and mined them for pathogenicity-related proteins and effector-encoding genes. De novo assembly of the genomes using Illumina reads resulted in 4,016 (63.1 Mb, N50 = 79 kb) and 3,245 (55.3 Mb, N50 = 61 kb) scaffolds for isolates 968-J2 and 968-S26, respectively, with an estimated genome size of 68 Mb. The mitochondrial genome has a similar size (approximately 43 kb) and structure to those of other oomycetes, plus several minor unique features. Repetitive elements, primarily retrotransposons, make up approximately 24% of the nuclear genome. Approximately 18,000 protein-coding gene models were predicted. Mining the secretome revealed approximately 120 candidate RxLR, six CRN (candidate effectors that elicit crinkling and necrosis), and 61 WY domain–containing proteins. Candidate RxLR effectors were shown to be predominantly undergoing diversifying selection, with approximately 57% located in variable gene-sparse regions of the genome. Aligning the P. tabacina genome to Hyaloperonospora arabidopsidis and Phytophthora spp. revealed a high level of synteny. Blocks of synteny show gene inversions and instances of expansion in intergenic regions. Extensive rearrangements of the gene-rich genomic regions do not appear to have occurred during the evolution of these highly variable pathogens. These assemblies provide the basis for studies of virulence in this and other downy mildew pathogens.

scholarly journals Mechanisms of Nuclear Suppression of Host Immunity by Effectors from the Arabidopsis Downy Mildew Pathogen Hyaloperonospora arabidopsidis (Hpa)

2012 ◽  
Vol 77 (0) ◽  
pp. 285-293 ◽  
Author(s):  
M.- C. Caillaud ◽  
L. Wirthmueller ◽  
G. Fabro ◽  
S. J. M. Piquerez ◽  
S. Asai ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Host Immunity ◽  
Hyaloperonospora Arabidopsidis

scholarly journals Effect of light and dark on the growth and development of downy mildew pathogen Hyaloperonospora arabidopsidis

2020 ◽  
Vol 69 (7) ◽  
pp. 1291-1300
Author(s):  
Osman Telli ◽  
Catherine Jimenez‐Quiros ◽  
John M. McDowell ◽  
Mahmut Tör
Keyword(s):  
Downy Mildew ◽  
Growth And Development ◽  
Hyaloperonospora Arabidopsidis ◽  
Effect Of Light

scholarly journals A set of Arabidopsis genes involved in the accommodation of the downy mildew pathogen Hyaloperonospora arabidopsidis

2019 ◽  
Vol 15 (7) ◽  
pp. e1007747 ◽  
Author(s):  
Martina Katharina Ried ◽  
Aline Banhara ◽  
Fang-Yu Hwu ◽  
Andreas Binder ◽  
Andrea A. Gust ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Hyaloperonospora Arabidopsidis
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