scholarly journals Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops

2019 ◽  
Vol 10 ◽  
Author(s):  
Pao Theen See ◽  
Elyce M. Iagallo ◽  
Richard P. Oliver ◽  
Caroline S. Moffat
Keyword(s):  
Heterologous Expression ◽  
Effector Proteins ◽  
Cereal Crops ◽  
Pyrenophora Tritici Repentis

scholarly journals Characterization of the ToxB Gene from Pyrenophora tritici-repentis

2001 ◽  
Vol 14 (5) ◽  
pp. 675-677 ◽  
Author(s):  
J. Patrick Martinez ◽  
Sean A. Ottum ◽  
Shaukat Ali ◽  
Leonard J. Francl ◽  
Lynda M. Ciuffetti
Keyword(s):  
Amino Acid ◽  
Pichia Pastoris ◽  
Heterologous Expression ◽  
North Dakota ◽  
Signal Peptide ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Pyrenophora Tritici Repentis ◽  
Putative Signal Peptide

The ToxB gene was cloned and characterized from a race 5 isolate of Pyrenophora tritici-repentis from North Dakota. ToxB contains a 261-bp open reading frame that encodes a 23 amino acid putative signal peptide and a 64 amino acid host-selective toxin, Ptr ToxB. Analysis of Ptr ToxB from heterologous expression in Pichia pastoris confirms that ToxB encodes a host-selective toxin.

scholarly journals Heterologous Expression of Functional Ptr ToxA

2000 ◽  
Vol 13 (4) ◽  
pp. 456-464 ◽  
Author(s):  
Robert P. Tuori ◽  
Thomas J. Wolpert ◽  
Lynda M. Ciuffetti
Keyword(s):  
Fusion Protein ◽  
Heterologous Expression ◽  
Specific Activity ◽  
Maximal Activity ◽  
Cysteine Residue ◽  
Binding Studies ◽  
Reading Frame ◽  
Pyrenophora Tritici Repentis ◽  
Ptr Toxa

Ptr ToxA, a proteinaceous host-selective toxin (HST) produced by the fungus Pyrenophora tritici-repentis, was expressed in Escherichia coli and purified as a polyhistidine-tagged, fusion protein (NC-FP). NC-FP, consisting of both the N and C domains of the ToxA open reading frame (ORF), is produced as an insoluble protein in E. coli at approximately 10 to 16 mg per liter of culture. Following in vitro refolding, NC-FP elicits cultivar-specific necrosis in wheat, with a specific activity similar to that of native Ptr ToxA. A fusion protein consisting of only the C domain has approximately 10 to 20% of the activity of native Ptr ToxA. These data suggest that (i) the N domain is important for maximal activity of Ptr ToxA, (ii) the N domain does not function to eliminate activity of the protoxin, and (iii) post-translational modifications of Ptr ToxA are not essential for activity. A C domain construct with a cysteine residue mutated to glycine is inactive. This, plus the observation that toxin activity is sensitive to reducing agents, provides evidence that the two cysteine residues in Ptr ToxA are involved in a disulfide bond that is essential for activity. The heterologous expression of Ptr ToxA provides a valuable tool for addressing a number of issues such as receptor binding studies, structure/function studies, and screening wheat cultivars for disease resistance.

scholarly journals PacBio genome sequencing reveals new insights into the genomic organisation of the multi-copy ToxB gene of the wheat fungal pathogen Pyrenophora tritici-repentis

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Paula Moolhuijzen ◽  
Pao Theen See ◽  
Caroline S. Moffat
Keyword(s):  
Virulence Factors ◽  
Single Gene ◽  
Tan Spot ◽  
Effector Proteins ◽  
Segmental Duplications ◽  
Flanking Sequence ◽  
Chromosome 10 ◽  
Single Chromosome ◽  
Pyrenophora Tritici Repentis ◽  
Ptr Toxa

Abstract Background Necrotrophic effector proteins secreted by fungal pathogens are important virulence factors that mediate the development of disease in wheat. Pyrenophora tritici-repentis (Ptr), the causal agent of wheat tan spot, has a race structure dependent on the combination of effectors. In Ptr, ToxA and ToxB are known proteinaceous effectors responsible for necrosis and chlorosis respectively. While Ptr ToxA is encoded by the single gene ToxA, ToxB has multiple loci in the Ptr genome, which is postulated to be directly related to the level of ToxB production and leaf chlorosis. Although previous analysis has indicated that the majority of the ToxB loci lie on a single chromosome, the exact number and chromosomal locations for all the ToxB loci have not been fully identified. Results In this study, we have sequenced the genome of a race 5 ToxB-producing isolate (DW5), using PacBio long read technology, and found that ToxB duplications are nested in the complex subtelomeric chromosomal regions. A total of ten identical ToxB gene copies were identified and based on flanking sequence identity, nine loci appeared associated with chromosome 10 and a single copy with chromosome 5. Chromosome 10 multiple ToxB gene loci were separated by large sequence regions between 31 and 66 kb within larger segmental duplications in an alternating pattern related to loci strand, and flanked by transposable elements. Conclusion This work provides for the first time the full accompaniment of ToxB loci and surrounding regions, and identifies the organization and distribution of ten ToxB loci to subtelomeric regions. To our knowledge, this is the first report of an interwoven strand-related duplication pattern event. This study further highlights the importance of resolving the highly complex distal chromosomal regions, that remain difficult to assemble, and can harbour important effectors and virulence factors.

scholarly journals Proteinaceous necrotrophic effectors in fungal virulence

2010 ◽  
Vol 37 (10) ◽  
pp. 907 ◽  
Author(s):  
Kar-Chun Tan ◽  
Richard P. Oliver ◽  
Peter S. Solomon ◽  
Caroline S. Moffat
Keyword(s):  
Fungal Pathogens ◽  
Host Plants ◽  
Triticum Aestivum L ◽  
Effector Proteins ◽  
Fungal Virulence ◽  
Pyrenophora Tritici Repentis ◽  
Necrotrophic Fungi ◽  
Necrotrophic Effectors ◽  
Inside Out ◽  
Shed Light

The host–pathogen interface can be considered as a biological battlefront. Molecules produced by both the pathogen and the host are critical factors determining the outcome of the interaction. Recent studies have revealed that an increasing number of necrotrophic fungal pathogens produce small proteinaceous effectors that are able to function as virulence factors. These molecules can cause tissue death in host plants that possess dominant sensitivity genes, leading to subsequent pathogen colonisation. Such effectors are only found in necrotrophic fungi, yet their roles in virulence are poorly understood. However, several recent key studies of necrotrophic effectors from two wheat (Triticum aestivum L.) pathogens, Pyrenophora tritici-repentis (Died.) Drechs. and Stagonospora nodorum (Berk.) Castell. & Germano, have shed light upon how these effector proteins serve to disable the host from the inside out.

Tan spot disease under the lenses of plant pathologists

2021 ◽  
pp. 589-622
Author(s):  
Reem Aboukhaddour ◽  
◽  
Mohamed Hafez ◽  
Stephen E. Strelkov ◽  
Myriam R. Fernandez ◽  
...  
Keyword(s):  
Plant Pathology ◽  
Crop Production ◽  
Plant Pathogens ◽  
Tan Spot ◽  
Cereal Crops ◽  
Comprehensive Review ◽  
Spot Disease ◽  
The Past ◽  
Pyrenophora Tritici Repentis ◽  
Tan Spot Disease

Necrotrophic plant pathogens pose an important threat to crop production, and many fungi in the Pleosporales have caused the sudden emergence of major epidemics on cereal crops. Tan spot of wheat, caused by Pyrenophora tritici-repentis, is one example, and since its emergence in the 1970s, scientists have explored its virulence and interactions with the host. In this chapter, our aim is to provide a comprehensive review of the most significant landmarks in tan spot research over the past 50 years from a plant pathology perspective.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

Formation of botanical composition of clover cereal and alfalfa cereal crops agrophytocenoses depending on sowing method

2020 ◽  
pp. 160-168
Author(s):  
I. Senyk
Keyword(s):  
Festuca Arundinacea ◽  
Global Climate ◽  
Phleum Pratense ◽  
Grass Species ◽  
Cereal Crops ◽  
Forest Steppe ◽  
Botanical Composition ◽  
Cross Sectional ◽  
Row Crops ◽  
Adverse Weather

Botanical composition of grasses is one of the most important indicators the biological value and quality of the obtained hay and pasture forage, the longevity of hayfi elds and pastures depend on. The issue of changing the botanical composition of agrophytocenoses is especially important in the context of global climate change, which in recent decades is also manifested in the territory of Ukraine, as it is possible to establish the most adapted species of legumes and cereals to adverse weather conditions and to identify eff ective technological methods of managing these processes for maximum conservation economically valuable species in the herbage. The purpose of the research is to establish the infl uence of diff erent ways of sowing of clover and alfalfa cereal crops agrophytocenoses on the formation of their botanical composition. Field studies have established diff erent eff ects of conventional in-line, cross-section and cross-sectional methods of sowing on the formation of botanical composition of grass mixtures of clover meadow (Trifolium pratense) varieties Sparta and Pavlyna with timothy meadow (Phleum pratense) and fenugreek multifl oral (Lolium multifl orum) and of agrophytocenoses of alfalfa of Sinyukha and Seraphima sowing varieties with reed fire (Festuca arundinacea Schreb) and middle wheatgrass (Elytrigia intermedia). For the average of four years of life of clover and alfalfa cereal crops agrophytocenoses, the highest proportion of legume component was observed with split-cross sowing – 51.6 % for Sparta, 53.1 % for Pavlyna, 60.3 % for Seraphima and 61.6 % for the Sinyukha variety. In the fourth year of life (the third year of use) of sowed leguminous-cereals agrophytocenoses, the preservation of the legume component was 14.6–15.5 % in clover-cereals grass mixtures with the Sparta variety and 16.0–16.8 % with the Pavlyna variety. In alfalfa grasslands, these indicators were 54.0–55.1 % with Seraphim and 55.0–56.2 % with Sinyukha. Among the studied varieties of clover meadow and alfalfa sowing proved better in the conditions of the Forest Steppe of western Pavlyna and Sinyukha. Cross-sectional and divided cross-sectional sowing of legumes and cereals mixtures proved to be better compared to conventional row crops in terms of conservation of economically valuable grass species. Key words: agrophytocenosis, botanical composition, clover meadow, alfalfa sowing, sowing methods.

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