Characterization of CRN-Like Genes From Plasmopara viticola: Searching for the Most Virulent Ones

Grapevine downy mildew is an insurmountable disease that endangers grapevine production and the wine industry worldwide. The causal agent of the disease is the obligate biotrophic oomycete Plasmopara viticola, for which the pathogenic mechanism remains largely unknown. Crinkling and necrosis proteins (CRN) are an ancient class of effectors utilized by pathogens, including oomycetes, that interfere with host plant defense reactions. In this study, 27 CRN-like genes were cloned from the P. viticola isolate YL genome, hereafter referred to as PvCRN genes, and characterized in silico and in planta. PvCRN genes in ‘YL’ share high sequence identities with their ortholog genes in the other three previously sequenced P. viticola isolates. Sequence divergence among the genes in the PvCRN family indicates that different PvCRN genes have different roles. Phylogenetic analysis of the PvCRN and the CRN proteins encoded by genes in the P. halstedii genome suggests that various functions might have been acquired by the CRN superfamily through independent evolution of Plasmopara species. When transiently expressed in plant cells, the PvCRN protein family shows multiple subcellular localizations. None of the cloned PvCRN proteins induced hypersensitive response (HR)-like cell death on the downy mildew-resistant grapevine Vitis riparia. This was in accordance with the result that most PvCRN proteins, except PvCRN11, failed to induce necrosis in Nicotiana benthamiana. Pattern-triggered immunity (PTI) induced by INF1 was hampered by several PvCRN proteins. In addition, 15 PvCRN proteins prevented Bax-induced plant programmed cell death. Among the cell death-suppressing members, PvCRN17, PvCRN20, and PvCRN23 were found to promote the susceptibility of N. benthamiana to Phytophthora capsici, which is a semi-biotrophic oomycete. Moreover, the nucleus-targeting member, PvCRN19, promoted the susceptibility of N. benthamiana to P. capsici. Therefore, these PvCRN proteins were estimated to be virulent effectors involved in the pathogenicity of P. viticola YL. Collectively, this study provides comprehensive insight into the CRN effector repertoire of P. viticola YL, which will help further elucidate the molecular mechanisms of the pathogenesis of grapevine downy mildew.

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Nonhost Versus Host Resistance to the Grapevine Downy Mildew, Plasmopara viticola, Studied at the Tissue Level

Phytopathology ◽

10.1094/phyto-98-7-0776 ◽

2008 ◽

Vol 98 (7) ◽

pp. 776-780 ◽

Cited By ~ 58

Author(s):

A. M. Díez-Navajas ◽

S. Wiedemann-Merdinoglu ◽

C. Greif ◽

D. Merdinoglu

Keyword(s):

Downy Mildew ◽

Host Specificity ◽

Plasmopara Viticola ◽

Defense Responses ◽

Tissue Level ◽

Vitis Riparia ◽

Grapevine Downy Mildew ◽

Resistance Factors ◽

Clear Cut ◽

Muscadinia Rotundifolia

Following inoculation of host and nonhost plants with Plasmopara viticola, the grapevine downy mildew, a histological survey was undertaken to identify the stage where its development is contained in nonhosts and in resistant host plants. Three herbaceous nonhost species, Beta vulgaris, Lactuca sativa, and Capsicum annuum, and three grapevine species displaying different level of resistance (Vitis vinifera [susceptible], Vitis riparia [partially resistant] and Muscadinia rotundifolia [totally resistant]) where inoculated by P. viticola using a controlled leaf disk inoculation bioassay. During the early steps of infection, defined as encystment of zoospores on stomata, penetration of the germ tube, and production of the vesicle with the primary hypha, there was no evidence of a clear-cut preference to grapevine tissues that could attest to host specificity. The main difference between host grapevine species and nonhosts was observed during the haustorium formation stage. In nonhost tissues, the infection was stopped by cell wall-associated defense responses before any mature haustorium could appear. Defense responses in resistant grapevines were triggered when haustoria were fully visible and corresponded to hypersensitive responses. These observations illustrate that, for P. viticola, haustorium formation is not only a key stage for the establishment of biotrophy but also for the host specificity and the recognition by grapevine resistance factors.

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The biological control of the grapevine downy mildew disease using Ochrobactrum sp.

Plant Protection Science ◽

10.17221/87/2019-pps ◽

2019 ◽

Vol 56 (No. 1) ◽

pp. 52-61 ◽

Cited By ~ 2

Author(s):

Chaoqun Zang ◽

Qiujun Lin ◽

Jinhui Xie ◽

Ying Lin ◽

Shuyi Yu ◽

...

Keyword(s):

Biological Control ◽

Downy Mildew ◽

Phytophthora Capsici ◽

Morphological Characteristics ◽

Good Control ◽

Plasmopara Viticola ◽

Antagonistic Activity ◽

Bacterial Strains ◽

Grapevine Downy Mildew

Grape downy mildew, caused by Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni 1888, is a widespread fungal disease that causes serious harm to the grape production. The long-term continuous use of chemical pesticides has caused issues with the resistance, residues and resurgence, as well as creating environmental pollution and the declining quality of the products. A biological control offers a safe and effective method to control diseases. We determined the in vitro antagonistic activity of 303 bacterial strains from infected grapevine leaves, and 12 isolates showed some level of antagonism in a detached leaf assay. Isolate SY286 reduced the disease severity in the detached leaves by 93.18%, and showed good control effects in a field assay. The scanning electron microscopy showed the damaged P. viticola cell walls when the mycelia and sporangia were treated with the fermentation liquor of isolate SY286. Furthermore, it showed an antagonistic activity against Phytophthora capsici, Phytophthora infestans, Botrytis cinerea, Fusarium oxysporum, Colletotrichum orbiculare, Trichothecium roseum, and Botryosphaeria berengeriana. The isolate was identified as Ochrobactrum sp. combined with its morphological characteristics, physiological and biochemical reactions and 16S rDNA sequence analysis, and it has the potential to control the grapevine downy mildew.

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The Grapevine E3 Ubiquitin Ligase VriATL156 Confers Resistance against the Downy Mildew Pathogen Plasmopara viticola

International Journal of Molecular Sciences ◽

10.3390/ijms22020940 ◽

2021 ◽

Vol 22 (2) ◽

pp. 940

Author(s):

Elodie Vandelle ◽

Pietro Ariani ◽

Alice Regaiolo ◽

Davide Danzi ◽

Arianna Lovato ◽

...

Keyword(s):

Downy Mildew ◽

Ubiquitin Ligase ◽

Control Measure ◽

Durable Resistance ◽

Genetic Resistance ◽

E3 Ubiquitin Ligase ◽

Plasmopara Viticola ◽

Vitis Vinifera L ◽

Vitis Species ◽

Vitis Riparia

Downy mildew, caused by Plasmopara viticola, is one of the most severe diseases of grapevine (Vitis vinifera L.). Genetic resistance is an effective and sustainable control strategy, but major resistance genes (encoding receptors for specific pathogen effectors) introgressed from wild Vitis species, although effective, may be non-durable because the pathogen can evolve to avoid specific recognition. Previous transcriptomic studies in the resistant species Vitis riparia highlighted the activation of signal transduction components during infection. The transfer of such components to V. vinifera might confer less specific and therefore more durable resistance. Here, we describe the generation of transgenic V. vinifera lines constitutively expressing the V. riparia E3 ubiquitin ligase gene VriATL156. Phenotypic and molecular analysis revealed that the transgenic plants were less susceptible to P. viticola than vector-only controls, confirming the role of this E3 ubiquitin ligase in the innate immune response. Two independent transgenic lines were selected for detailed analysis of the resistance phenotype by RNA-Seq and microscopy, revealing the profound reprogramming of transcription to achieve resistance that operates from the earliest stages of pathogen infection. The introduction of VriATL156 into elite grapevine cultivars could therefore provide an effective and sustainable control measure against downy mildew.

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A High-Quality Grapevine Downy Mildew Genome Assembly Reveals Rapidly Evolving and Lineage-Specific Putative Host Adaptation Genes

Genome Biology and Evolution ◽

10.1093/gbe/evz048 ◽

2019 ◽

Vol 11 (3) ◽

pp. 954-969 ◽

Cited By ~ 12

Author(s):

Yann Dussert ◽

Isabelle D Mazet ◽

Carole Couture ◽

Jérôme Gouzy ◽

Marie-Christine Piron ◽

...

Keyword(s):

Downy Mildew ◽

Genome Assembly ◽

Population Genomics ◽

Plasmopara Viticola ◽

Plant Diseases ◽

Host Specialization ◽

Grapevine Downy Mildew ◽

Downy Mildews ◽

Genes Encoding ◽

High Level

Abstract Downy mildews are obligate biotrophic oomycete pathogens that cause devastating plant diseases on economically important crops. Plasmopara viticola is the causal agent of grapevine downy mildew, a major disease in vineyards worldwide. We sequenced the genome of Pl. viticola with PacBio long reads and obtained a new 92.94 Mb assembly with high contiguity (359 scaffolds for a N50 of 706.5 kb) due to a better resolution of repeat regions. This assembly presented a high level of gene completeness, recovering 1,592 genes encoding secreted proteins involved in plant–pathogen interactions. Plasmopara viticola had a two-speed genome architecture, with secreted protein-encoding genes preferentially located in gene-sparse, repeat-rich regions and evolving rapidly, as indicated by pairwise dN/dS values. We also used short reads to assemble the genome of Plasmopara muralis, a closely related species infecting grape ivy (Parthenocissus tricuspidata). The lineage-specific proteins identified by comparative genomics analysis included a large proportion of RxLR cytoplasmic effectors and, more generally, genes with high dN/dS values. We identified 270 candidate genes under positive selection, including several genes encoding transporters and components of the RNA machinery potentially involved in host specialization. Finally, the Pl. viticola genome assembly generated here will allow the development of robust population genomics approaches for investigating the mechanisms involved in adaptation to biotic and abiotic selective pressures in this species.

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Factors affecting zoospore responses towards stomata in hop downy mildew (Pseudoperonospora humuli) including some comparisons with grapevine downy mildew (Plasmopara viticola)

Physiological Plant Pathology ◽

10.1016/0048-4059(73)90013-1 ◽

1973 ◽

Vol 3 (3) ◽

pp. 405-417 ◽

Cited By ~ 31

Author(s):

D.J. Royle ◽

G.G. Thomas

Keyword(s):

Downy Mildew ◽

Plasmopara Viticola ◽

Factors Affecting ◽

Grapevine Downy Mildew ◽

Pseudoperonospora Humuli

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Isolation of Plasmopara viticola from Grapevine Leaves

Proceedings ◽

10.3390/proceedings2019029034 ◽

2019 ◽

Vol 29 (1) ◽

pp. 34

Author(s):

Camelia Ungureanu ◽

Liliana Cristina Soare ◽

Diana Vizitiu ◽

Mirela Calinescu ◽

Irina Fierascu ◽

...

Keyword(s):

Downy Mildew ◽

Plasmopara Viticola ◽

Grapevine Downy Mildew ◽

Grapevine Leaves ◽

Downy Mildew Disease

In order to test some biofungicides, the isolation of Plasmopara viticola was carried out.Plasmopara viticola is a fungus that causes the grapevine downy mildew disease [...]

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Identification of the First Oomycete Mating-type Locus Sequence in the Grapevine Downy Mildew Pathogen, Plasmopara viticola

Current Biology ◽

10.1016/j.cub.2020.07.057 ◽

2020 ◽

Vol 30 (20) ◽

pp. 3897-3907.e4 ◽

Cited By ~ 4

Author(s):

Yann Dussert ◽

Ludovic Legrand ◽

Isabelle D. Mazet ◽

Carole Couture ◽

Marie-Christine Piron ◽

...

Keyword(s):

Downy Mildew ◽

Mating Type ◽

Plasmopara Viticola ◽

Type Locus ◽

Grapevine Downy Mildew ◽

Mating Type Locus

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Draft Genome Sequence of Plasmopara viticola , the Grapevine Downy Mildew Pathogen

Genome Announcements ◽

10.1128/genomea.00987-16 ◽

2016 ◽

Vol 4 (5) ◽

Cited By ~ 17

Author(s):

Yann Dussert ◽

Jérôme Gouzy ◽

Sylvie Richart-Cervera ◽

Isabelle D. Mazet ◽

Laurent Delière ◽

...

Keyword(s):

Downy Mildew ◽

Genome Sequence ◽

Genome Analysis ◽

Plant Pathogen ◽

Host Resistance ◽

Draft Genome ◽

Plasmopara Viticola ◽

Host Specialization ◽

Grapevine Downy Mildew ◽

Plant Pathogen Interactions

Plasmopara viticola is a biotrophic pathogenic oomycete responsible for grapevine downy mildew. We present here the first draft of the P. viticola genome. Analysis of this sequence will help in understanding plant-pathogen interactions in oomycetes, especially pathogen host specialization and adaptation to host resistance.

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