scholarly journals UhAVR1, an HR-triggering avirulence effector of Ustilago hordei, is secreted via the ER-Golgi pathway to the cytosol of barley coleoptile cells and contributes to virulence early in infection

2020 ◽  
Author(s):  
Ana Priscilla Montenegro Alonso ◽  
Shawkat Ali ◽  
Xiao Song ◽  
Rob Linning ◽  
Guus Bakkeren
Keyword(s):  
Natural Infection ◽  
Resistance Breeding ◽  
Infection Process ◽  
Molecular Function ◽  
Avirulence Genes ◽  
Heterologous Host ◽  
Common Component ◽  
Barley Cultivars ◽  
Ustilago Hordei ◽  
Virulence Effectors

AbstractThe basidiomycete Ustilago hordei (Uh) causes covered smut disease of barley and oats. Virulence effectors that aid the infection process and support the pathogen’s lifestyle have been described for this fungus. Genetically, six avirulence genes are known and one codes for UhAVR1, the only proven avirulence effector identified in smut pathogens to date that triggers complete immunity in barley cultivars carrying the resistance gene Ruh1. A prerequisite for resistance breeding is understanding the host targets and molecular function of UhAVR1. Analysis of this effector upon natural infection of barley coleoptiles using teliospores showed that UhAVR1 is expressed during the early stages of fungal infection where it leads to HR triggering in resistant cultivars or performs its virulence function in susceptible cultivars. Fungal secretion of UhAVR1 is directed by its signal peptide and occurs via the BrefeldinA-sensitive ER-Golgi pathway, both in cell culture away from its host, and during barley interaction. Transient expression of this effector in barley and a heterologous host, Nicotiana benthamiana (Nb), supports a cytosolic localization. Delivery of UhAVR1 via foxtail mosaic virus, Pseudomonas species or Agrobacterium-mediated suppression of cell inducers in barley and Nb support a role in the suppression of a common component(s) of ETI and PTI which is conserved in both plant systems.

scholarly journals UhAVR1, an HR-Triggering Avirulence Effector of Ustilago hordei, Is Secreted via the ER–Golgi Pathway, Localizes to the Cytosol of Barley Cells during in Planta-Expression, and Contributes to Virulence Early in Infection

2020 ◽  
Vol 6 (3) ◽  
pp. 178 ◽  
Author(s):  
Ana Priscilla Montenegro Alonso ◽  
Shawkat Ali ◽  
Xiao Song ◽  
Rob Linning ◽  
Guus Bakkeren
Keyword(s):  
Nicotiana Benthamiana ◽  
Natural Infection ◽  
Resistance Breeding ◽  
Molecular Function ◽  
Avirulence Genes ◽  
In Planta ◽  
Barley Cultivars ◽  
Ustilago Hordei ◽  
Pseudomonas Species ◽  
Virulence Effectors

The basidiomycete Ustilago hordei causes covered smut disease of barley and oats. Virulence effectors promoting infection and supporting pathogen lifestyle have been described for this fungus. Genetically, six avirulence genes are known and one codes for UhAVR1, the only proven avirulence effector identified in smuts to date that triggers complete immunity in barley cultivars carrying resistance gene Ruh1. A prerequisite for resistance breeding is understanding the host targets and molecular function of UhAVR1. Analysis of this effector upon natural infection of barley coleoptiles using teliospores showed that UhAVR1 is expressed during the early stages of fungal infection where it leads to HR triggering in resistant cultivars or performs its virulence function in susceptible cultivars. Fungal secretion of UhAVR1 is directed by its signal peptide and occurs via the BrefeldinA-sensitive ER–Golgi pathway in cell culture away from its host. Transient in planta expression of UhAVR1 in barley and a nonhost, Nicotiana benthamiana, supports a cytosolic localization. Delivery of UhAVR1 via foxtail mosaic virus or Pseudomonas species in both barley and N. benthamiana reveals a role in suppressing components common to both plant systems of Effector- and Pattern-Triggered Immunity, including necrosis triggered by Agrobacterium-delivered cell death inducers.

scholarly journals Nanoparticles as Adjuvants and Nanodelivery Systems for mRNA-Based Vaccines

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 45
Author(s):  
Iman M. Alfagih ◽  
Basmah Aldosari ◽  
Bushra AlQuadeib ◽  
Alanood Almurshedi ◽  
Mariyam M. Alfagih
Keyword(s):  
Messenger Rna ◽  
Immune Cell ◽  
Natural Infection ◽  
Immunological Response ◽  
Infection Process ◽  
Dual Function ◽  
Therapeutic Vaccines ◽  
Non Invasive ◽  
Recent Developments

Messenger RNA (mRNA)-based vaccines have shown promise against infectious diseases and several types of cancer in the last two decades. Their promise can be attributed to their safety profiles, high potency, and ability to be rapidly and affordably manufactured. Now, many RNA-based vaccines are being evaluated in clinical trials as prophylactic and therapeutic vaccines. However, until recently, their development has been limited by their instability and inefficient in vivo transfection. The nanodelivery system plays a dual function in RNA-based vaccination by acting as a carrier system and as an adjuvant. That is due to its similarity to microorganisms structurally and size-wise; the nanodelivery system can augment the response by the immune system via simulating the natural infection process. Nanodelivery systems allow non-invasive mucosal administration, targeted immune cell delivery, and controlled delivery, reducing the need for multiple administrations. They also allow co-encapsulating with immunostimulators to improve the overall adjuvant capacity. The aim of this review is to discuss the recent developments and applications of biodegradable nanodelivery systems that improve RNA-based vaccine delivery and enhance the immunological response against targeted diseases.

scholarly journals Identification of a Novel Locus Rmo2 Conditioning Resistance in Barley to Host-Specific Subgroups of Magnaporthe oryzae

2012 ◽  
Vol 102 (7) ◽  
pp. 674-682 ◽  
Author(s):  
Nguyen Thi Thanh Nga ◽  
Yoshihiro Inoue ◽  
Izumi Chuma ◽  
Gang-Su Hyon ◽  
Kazuma Okada ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Molecular Mapping ◽  
The Other ◽  
Avirulence Gene ◽  
Barley Cultivar ◽  
Avirulence Genes ◽  
Genetic Crosses ◽  
Barley Cultivars ◽  
Genetic Mechanisms ◽  
Common Parent

Barley cultivars show various patterns of resistance against isolates of Magnaporthe oryzae and M. grisea. Genetic mechanisms of the resistance of five representative barley cultivars were examined using a highly susceptible barley cultivar, ‘Nigrate’, as a common parent of genetic crosses. The resistance of the five cultivars against Setaria, Oryza, Eleusine, and Triticum isolates of M. oryzae was all attributed to a single locus, designated as Rmo2. Nevertheless, the Rmo2 locus in each cultivar was effective against a different range of isolates. Genetic analyses of pathogenicity suggested that each cultivar carries an allele at the Rmo2 locus that recognizes a different range of avirulence genes. One allele, Rmo2.a, corresponded to PWT1, which conditioned the avirulence of Setaria and Oryza isolates on wheat, in a gene-for-gene manner. The other alleles, Rmo2.b, Rmo2.c, and Rmo2.d, corresponded to more than one avirulence gene. On the other hand, the resistance of those cultivars to another species, M. grisea, was conditioned by another locus, designated as Rmo3. These results suggest that Rmo2 is effective against a broad range of blast isolates but is specific to M. oryzae. Molecular mapping revealed that Rmo2 is located on the 7H chromosome.

GENETIC CONTROL OF VIRULENCE IN USTILAGO HORDEI. II. SEGREGATIONS FOR HIGHER LEVELS OF VIRULENCE

1971 ◽  
Vol 13 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Gurmel Sidhu ◽  
Clayton Person
Keyword(s):  
Genetic Control ◽  
Virulence Genes ◽  
Barley Cultivars ◽  
Ustilago Hordei

Genetics of virulence of Ustilago hordei towards five barley cultivars (Excelsior, Vantage, Hannchen, Trebi and Lion) was investigated. Two genes, Uhv-1 and Uhv-2, were identified; Uhv-2 was effective on Excelsior, and Uhv-1 on both Hannchen and Vantage. The virulence genes were both recessive.

scholarly journals Fusarium Head Blight and Deoxynivalenol Accumulation of Barley in Eastern Canada: Cultivar Response and Correlation Analysis

Plant Disease ◽  
2004 ◽  
Vol 88 (8) ◽  
pp. 837-844 ◽  
Author(s):  
T. M. Choo ◽  
R. A. Martin ◽  
K. M. Ho ◽  
Q. Shen ◽  
G. Fedak ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Plant Traits ◽  
Natural Infection ◽  
Heading Date ◽  
Head Blight ◽  
Eastern Canada ◽  
Barley Cultivars ◽  
Barley Yellow Dwarf ◽  
Infection Susceptibility ◽  
Performance Trial

Fusarium head blight of barley (Hordeum vulgare) is a devastating disease in many countries. We undertook a study to identify barley cultivars, if any, that are resistant to Fusarium head blight and deoxynivalenol (DON) accumulation and to determine if DON concentration is correlated with other plant traits in Eastern Canada and China. Barley cultivars were grown in the field under artificial inoculation conditions at two locations (Charlottetown and Ottawa) in Canada during two summers and at Hangzhou in China during two winters. Seed samples were collected for DON analysis from the barley performance trial at five locations in Ontario. None of the 64 barley cultivars were immune to Fusarium head blight infection. Two-row cultivars, however, were significantly more resistant to Fusarium head blight infection and DON accumulation than six-row cultivars. Three cultivars (Island, AC Alberte, and Chevron) were found to be most resistant, as they were consistently low in Fusarium head blight incidence and DON concentration in both Eastern Canada and China. In six-row barley, DON concentration was correlated positively with Fusarium head blight incidence at both Charlottetown and Ottawa, and it was negatively correlated with plant height at Ottawa. DON concentration and heading date were not consistently correlated. Barley yellow dwarf and powdery mildew appeared to have very little effect on Fusarium head blight infection. Susceptibility to DON accumulation did not result in low yield under natural infection conditions in Ontario. Cultivar × location interactions for DON concentration, Fusarium head blight incidence, and heading date were significant.

IDENTICAL GENES FOR VIRULENCE IN THE SMUTS USTILAGO HORDEI AND U. NIGRA, AND INHERITANCE OF VIRULENCE ON THE BARLEY CULTIVARS KEYSTONE AND CONQUEST

1974 ◽  
Vol 54 (2) ◽  
pp. 253-257 ◽  
Author(s):  
R. A. FULLERTON ◽  
J. NIELSEN
Keyword(s):  
Hordeum Vulgare ◽  
Virulence Genes ◽  
Recessive Gene ◽  
Breeding Program ◽  
Hordeum Vulgare L ◽  
Barley Cultivars ◽  
Ustilago Hordei

Virulence of Ustilago hordei (Pers.) Lagerh. and U. nigra Tapke on the barley (Hordeum vulgare L.) cultivars Keystone and Conquest was studied. One recessive gene or linked genes, the same in both smut species, appeared to confer virulence on both cultivars. Earlier investigators had found identical virulence genes in both species of smut for the cultivars Excelsior, Lion, Pannier and Trebi. Therefore, testing for resistance or susceptibility in a breeding program could be done with a strain of only one of the species.

scholarly journals Screening for Alternaria brassicicola resistance in the Brassicaceae: Bio-assay optimization and confocal microscopy insights into the infection process

2016 ◽  
Author(s):  
Marzena Nowakowska ◽  
Małgorzata Wrzesińska ◽  
Piotr Kamiński ◽  
Marcin Nowicki ◽  
Małgorzata Lichocka ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Incubation Temperature ◽  
Leaf Age ◽  
Genetic Resistance ◽  
Field Tests ◽  
Resistance Breeding ◽  
Infection Process ◽  
Host Cells ◽  
Alternaria Brassicicola ◽  
Assay Optimization

Heavy losses incited yearly by Alternaria brassicicola on the vegetable Brassicaceae – have prompted our search for sources of genetic resistance against the pathogen and the resultant disease, dark leaf spot. We optimized several parameters to test the performance of the plants under controlled conditions to this disease, including leaf age and position, inoculum concentration, and incubation temperature. Using these optimized conditions, we screened a collection of 38 Brassicaceae cultigens with two methods (detached leaf and seedlings). Our results show, that either method can be used for the A. brassicicola resistance breeding, while the plant’s genotype was crucial in determining its response to the pathogen. The laboartory bio-assays for A. brassicicola resistance were run under more stringent conditions than the field tests, and resulted in identification of two interspecific hybrids that might be used in breeding programs. Confocal microscopy analyses of the leaf samples provided data into the pathogen mode of infection: Direct epidermal infection or stomatal attack were related to plants’ resistance against A. brassicicola among the cultigens tested. Further, the actin network of the host cells reorganized around the papillas deposited under the pathogen’s appressorium.

scholarly journals Screening for Alternaria brassicicola resistance in the Brassicaceae: Bio-assay optimization and confocal microscopy insights into the infection process

2015 ◽  
Author(s):  
Marzena Nowakowska ◽  
Małgorzata Wrzesińska ◽  
Piotr Kamiński ◽  
Marcin Nowicki ◽  
Małgorzata Lichocka ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Incubation Temperature ◽  
Leaf Age ◽  
Genetic Resistance ◽  
Field Tests ◽  
Resistance Breeding ◽  
Infection Process ◽  
Host Cells ◽  
Alternaria Brassicicola ◽  
Assay Optimization

Heavy losses incited yearly by Alternaria brassicicola on the vegetable Brassicaceae – have prompted our search for sources of genetic resistance against the resultant disease, dark leaf spot. We optimized several parameters to test the performance of the plants under controlled conditions to this disease, including leaf age and position, inoculum concentration, and incubation temperature. Using these optimized conditions, we screened a collection of 38 Brassicaceae cultigens with two methods (detached leaf and seedlings). Our results show, that either method can be used for the A. brassicicola resistance breeding, while the plant’s genotype was crucial in determining its response to the pathogen. The bio-assays for Alternaria resistance were more effective than the field tests, and resulted in identification of two interspecific hybrids that might be used in breeding programs. Confocal microscopy analyses of the leaf samples provided novel insights into the pathogen mode of infection: Direct epidermal infection or stomatal attack were dependent on plants’ resistance against A. brassicicola. Further, the actin network of the host cells reorganized around the papillas deposited under the pathogen’s appressorium. Papilla composition is predicted to be important in determining the plant’s resistance.

scholarly journals Responses of Barley Cultivars and Lines to Isolates of Pyrenophora teres

Plant Disease ◽  
1998 ◽  
Vol 82 (3) ◽  
pp. 316-321 ◽  
Author(s):  
A. Douiyssi ◽  
D. C. Rasmusson ◽  
A. P. Roelfs
Keyword(s):  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Resistance Breeding ◽  
Adult Plant ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Seedling Resistance ◽  
Barley Cultivars ◽  
Pathogenic Variability ◽  
High Level

Net blotch, caused by Pyrenophora teres, is among the most damaging foliar diseases of barley worldwide. A knowledge of the reaction of local cultivars, putative resistant lines, and variability in the net blotch pathogen is necessary to develop a successful resistance breeding program. Disease responses of 38 barley lines to 15 P. teres isolates were studied at the seedling and adult plant stages in the glasshouse, and field responses to net blotch were evaluated at three Moroccan locations. No tested barley was resistant to all isolates, and resistance was apparently of the specific type. Pathogenic variability was great, as none of the 15 isolates were identical. For each isolate tested, a specific high level of resistance was found in one or more host lines. Seedling and adults plants often differed in response to the same isolate. Adult plant resistance was commonly observed in response to isolate I-1, and seedling resistance was more common to isolate I-14. Adult plant resistance of nine lines was undetected in seedling evaluations using isolate I-1. The seedling glasshouse and field responses of the barley lines varied considerably, limiting the value of seedling testing for resistance. Field reactions of resistant and moderately resistant were consistent across the three locations for the lines Heartland, Minn 7, CI 2333, and CI 2549. The variability observed in P. teres and failure to find lines with resistance to all isolates suggests that breeding for resistance should emphasize pyramiding of resistance genes.

scholarly journals A Zoospore Inoculation Method with Phytophthora sojae to Assess the Prophylactic Role of Silicon on Soybean Cultivars

Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1632-1638 ◽  
Author(s):  
Valérie Guérin ◽  
Amandine Lebreton ◽  
Erik E. Cogliati ◽  
Sue E. Hartley ◽  
François Belzile ◽  
...  
Keyword(s):  
Natural Infection ◽  
Infection Process ◽  
Phytophthora Sojae ◽  
Controlled Environment ◽  
Hydroponic System ◽  
Soybean Cultivars ◽  
Direct Inoculation ◽  
Soybean Plants ◽  
Root Resistance

The objective of this study was to evaluate whether silicon (Si) amendments, known to have a prophylactic role against biotrophic and hemibiotrophic pathogens, could protect soybean against Phytophthora sojae. To fulfill this objective, the initial challenge was to develop a method of inoculation that reproduced the natural infection process while allowing regular Si feeding to the plants. In a first set of experiments, inoculation of P. sojae zoospores directly into hydroponic solutions led to reproducible infections and expected phenotypes when using ‘Williams’ (rps), ‘L75-6141’ (Rps1a), ‘haro15’ (Rps1k), and ‘L77-1863’ (Rps1b) soybean challenged to races 3 and 7 of P. sojae. This approach offers the advantage of testing simultaneously many soybean cultivars against different races of P. sojae in a controlled environment, and the expression of partial and root resistance. In a second set of experiments aimed at testing the effect of Si, our results clearly showed that Si amendments had a significant effect on disease reduction and plant yield. The effect was particularly noticeable when combined with a cultivar displaying a certain level of resistance to the disease. These results demonstrate a useful method of direct inoculation of soybean plants with P. sojae zoospores through a hydroponic system and show that Si amendments can represent an alternative method of control of P. sojae against soybean.

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