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 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.

A vector system for fast-forward studies of the HOPZ-ACTIVATED RESISTANCE1 (ZAR1) resistosome in the model plant Nicotiana benthamiana

2021 ◽  
Author(s):  
Adeline Harant ◽  
Hsuan Pai ◽  
Toshiyuki Sakai ◽  
Sophien Kamoun ◽  
Hiroaki Adachi
Keyword(s):  
Nicotiana Benthamiana ◽  
Cell Biology ◽  
Plant Immunity ◽  
Transient Gene Expression ◽  
Coiled Coil ◽  
Experimental System ◽  
Vector System ◽  
In Planta ◽  
Functional Studies

Abstract Nicotiana benthamiana has emerged as a complementary experimental system to Arabidopsis thaliana. It enables fast-forward in vivo analyses primarily through transient gene expression and is particularly popular in the study of plant immunity. Recently, our understanding of nucleotide-binding leucine-rich repeat (NLR) plant immune receptors has greatly advanced following the discovery of the Arabidopsis HOPZ-ACTIVATED RESISTANCE1 (ZAR1) resistosome. Here, we describe a vector system of 72 plasmids that enables functional studies of the ZAR1 resistosome in N. benthamiana. We showed that ZAR1 stands out among the coiled coil class of NLRs (CC-NLRs) for being highly conserved across distantly related dicot plant species and confirmed NbZAR1 as the N. benthamiana ortholog of Arabidopsis ZAR1. Effector-activated and autoactive NbZAR1 trigger the cell death response in N. benthamiana and this activity is dependent on a functional N-terminal α1 helix. C-terminally tagged NbZAR1 remains functional in N. benthamiana, thus enabling cell biology and biochemical studies in this plant system. We conclude that the NbZAR1 open source pZA plasmid collection forms an additional experimental system to Arabidopsis for in planta resistosome studies.

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.

scholarly journals Evidence for Functional Diversification Within a Fungal NEP1-Like Protein Family

2013 ◽  
Vol 26 (3) ◽  
pp. 278-286 ◽  
Author(s):  
Parthasarathy Santhanam ◽  
H. Peter van Esse ◽  
Isabell Albert ◽  
Luigi Faino ◽  
Thorsten Nürnberger ◽  
...  
Keyword(s):  
Gene Family ◽  
Vegetative Growth ◽  
Nicotiana Benthamiana ◽  
Family Members ◽  
Aerial Mycelium ◽  
Vascular Wilt ◽  
In Planta ◽  
Functional Diversification ◽  
Targeted Deletion ◽  
Genes Encoding

In this study, we functionally analyzed the gene family encoding necrosis- and ethylene-inducing-like proteins (NLP) of the vascular wilt pathogen Verticillium dahliae. We show that the composition of the NLP gene family varies little among V. dahliae isolates. The cytotoxic activity of NLP family members of a tomato-pathogenic V. dahliae strain was determined, demonstrating that only two of the seven NLP induced plant cell death. The genes encoding these cytotoxic NLP were found to be induced in V. dahliae upon colonization of tomato. Interestingly, targeted deletion of either of the two genes in V. dahliae significantly compromised virulence on tomato as well as on Arabidopsis plants, whereas deletion of only one of the two genes affected virulence on Nicotiana benthamiana. This could be attributed to differential induction of the two NLP genes in V. dahliae upon N. benthamiana colonization, revealing that the in planta induction of NLP genes varies between plant hosts. Intriguingly, one of the NLP genes appears to also affect vegetative growth and conidiospore production, because the corresponding deletion strain produced significantly fewer conidiospores and developed extensive aerial mycelium. In conclusion, we demonstrate that the expanded V. dahliae NLP family shows functional diversification, revealing not only differential cytotoxicity between family members but also that the cytotoxic NLP play a role in vegetative growth and asexual reproduction in addition to their contribution to virulence.

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 Highly active engineered IgG3 antibodies against SARS-CoV-2

2021 ◽  
Vol 118 (42) ◽  
pp. e2107249118
Author(s):  
Somanath Kallolimath ◽  
Lin Sun ◽  
Roman Palt ◽  
Karin Stiasny ◽  
Patrick Mayrhofer ◽  
...  
Keyword(s):  
Nicotiana Benthamiana ◽  
Vaccine Development ◽  
Binding Activity ◽  
The Other ◽  
Cross Linking ◽  
Antigen Binding ◽  
In Planta ◽  
Antigen Binding Site ◽  
Highly Active ◽  
Viral Surface

Monoclonal antibodies (mAbs) that efficiently neutralize SARS-CoV-2 have been developed at an unprecedented speed. Notwithstanding, there is a vague understanding of the various Ab functions induced beyond antigen binding by the heavy-chain constant domain. To explore the diverse roles of Abs in SARS-CoV-2 immunity, we expressed a SARS-CoV-2 spike protein (SP) binding mAb (H4) in the four IgG subclasses present in human serum (IgG1-4) using glyco-engineered Nicotiana benthamiana plants. All four subclasses, carrying the identical antigen-binding site, were fully assembled in planta and exhibited a largely homogeneous xylose- and fucose-free glycosylation profile. The Ab variants ligated to the SP with an up to fivefold increased binding activity of IgG3. Furthermore, all H4 subtypes were able to neutralize SARS-CoV-2. However, H4-IgG3 exhibited an up to 50-fold superior neutralization potency compared with the other subclasses. Our data point to a strong protective effect of IgG3 Abs in SARS-CoV-2 infection and suggest that superior neutralization might be a consequence of cross-linking the SP on the viral surface. This should be considered in therapy and vaccine development. In addition, we underscore the versatile use of plants for the rapid expression of complex proteins in emergency cases.

scholarly journals In Planta Interaction and Transreplication of Distinct Begomoviruses and their Associated Components

2021 ◽  
Vol 26 (01) ◽  
pp. 45-51
Author(s):  
Muhammad Naeem Sattar
Keyword(s):  
Nicotiana Benthamiana ◽  
Blot Hybridization ◽  
Low Frequency ◽  
Southern Blot Hybridization ◽  
Bipartite Begomoviruses ◽  
In Planta ◽  
Monopartite Begomovirus ◽  
Structural Resemblance ◽  
Rep Proteins ◽  
Viral Components

The studies described here were intended to examine the transreplication and interactions abilities of a widespread ToLCNDV, and an emerging begomovirus PeLCV associated with its cognate betasatellite TbLCuB. PeLCV, a monopartite begomovirus, has been characterized from many important crops, vegetables and weeds along with its associated TbLCuB. The DNA-B of bipartite ToLCNDV genome has been successfully transreplicated by the DNA-A of different bipartite begomoviruses, albeit with low frequency. Whether PeLCV can transreplicate DNA-B of ToLCNDV is unknown. To unravel this notion, both these viruses were inoculated to the model Nicotiana benthamiana plants in all possible combinations and the in planta existence of viral components were verified by PCR and Southern blot hybridization. The results demonstrated that PeLCV transreplicated and maintained ToLCNDV DNA-B. Whereas, ToLCNDV DNA-A could not transreplicate TbLCuB. Analyses of Rep proteins structure of ToLCNDV and PeLCV revealed a structural resemblance, whereas putative iteron-binding sequences of PeLCV were compatible with the Rep-binding iterons of ToLCNDV-B. The results suggested that PeLCV and ToLCNDV DNA-B can interact synergistically and can be disastrous under field conditions. © 2021 Friends Science Publishers

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.

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