scholarly journals Tramesan Elicits Durum Wheat Defence Against the Septoria Leaf Blotch Complex

2020 ◽  
Author(s):  
VALERIA Scala ◽  
Chiara Pietricola ◽  
valentina farina ◽  
marzia beccaccioli ◽  
slaven zjalic ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Field Experiments ◽  
Animal Health ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Animal Cells ◽  
Zymoseptoria Tritici ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Wheat Field

The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce global yearly yield of wheat by up to 50%. In the last decade in Italy, SLBC incidence has increased; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health, and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g. mycotoxins). Specifically, we identified Tramesan: a 23 KDa -heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spraying of Tramesan (3.3 µM) in SLBC-susceptible varieties of durum significantly diminished symptoms of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB) by 75% and 65%, respectively. Tests were conducted under controlled conditions as well as in field. We show that Tramesan elicits wheat defence against SNB and STB augmenting the synthesis of defence-related hormones, notably JA and SA, that in turn switch on the expression of markers of defence (PR1, PR4 inter alia). In field experiments, yield of durum wheat plants treated with Tramesan was similar to that of untreated ones. The results suggest the use of Tramesan for protecting durum wheat against SLBC.

scholarly journals Tramesan Elicits Durum Wheat Defense against the Septoria Disease Complex

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 608 ◽  
Author(s):  
Valeria Scala ◽  
Chiara Pietricola ◽  
Valentina Farina ◽  
Marzia Beccaccioli ◽  
Slaven Zjalic ◽  
...  
Keyword(s):  
Plant Defense ◽  
Durum Wheat ◽  
Field Experiments ◽  
Disease Incidence ◽  
Animal Health ◽  
Foliar Spray ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Controlled Conditions

The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce wheat global yearly yield by up to 50%. In the last decade, SLBC incidence has increased in Italy; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g., mycotoxins). Specifically, we identified Tramesan: a 23 kDa α-heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spray of Tramesan (3.3 μM) on SLBC-susceptible durum wheat cultivars, before inoculation of causal agents of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB), significantly decreased disease incidence both in controlled conditions (SNB: −99%, STB: −75%) and field assays (SNB: −25%, STB: −30%). We conducted these tests were conducted under controlled conditions as well as in field. We showed that Tramesan increased the levels of jasmonic acid (JA), a plant defense-related hormone. Tramesan also increased the early expression (24 hours after inoculation—hai) of plant defense genes such as PR4 for SNB infected plants, and RBOH, PR1, and PR9 for STB infected plants. These results suggest that Tramesan protects wheat by eliciting plant defenses, since it has no direct fungicidal activity. In field experiments, the yield of durum wheat plants treated with Tramesan was similar to that of healthy untreated plots. These results encourage the use of Tramesan to protect durum wheat against SLBC.

scholarly journals Improved control of Septoria tritici blotch in durum wheat using cultivar mixtures

2019 ◽  
Author(s):  
S. Ben M’Barek ◽  
P. Karisto ◽  
W. Abdedayem ◽  
M. Laribi ◽  
M. Fakhfakh ◽  
...  
Keyword(s):  
Disease Control ◽  
Durum Wheat ◽  
Field Experiments ◽  
Substantial Reduction ◽  
Resistant Cultivar ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Similar Degree ◽  
Pure Stand ◽  
Cultivar Mixtures

AbstractMixtures of cultivars with contrasting levels of resistance can suppress infectious diseases in wheat, as demonstrated in numerous field experiments. Most studies focused on airborne pathogens in bread wheat, while splash-dispersed pathogens have received less attention, and no studies have been conducted in durum wheat. We conducted a two-year field experiment in Tunisia, to evaluate the performance of cultivar mixtures with varying proportions of resistance (0–100%) in controlling the polycyclic, splash-dispersed disease Septoria tritici blotch (STB) in durum wheat. To measure STB severity, we used a high-throughput method based on digital image analysis of 3074 infected leaves collected from 42 and 40 experimental plots during the first and second years, respectively. This allowed us to quantify pathogen reproduction on wheat leaves and to acquire a large dataset that exceeds previous studies with respect to accuracy and precision. Our analyses show that introducing only 25% of a disease-resistant cultivar into a pure stand of a susceptible cultivar provides a substantial reduction of almost 50% in disease severity compared to the susceptible pure stand. However, comprising the resistant component of two cultivars instead of one did not further improve disease control, contrary to predictions of epidemiological theory. Susceptible cultivars can be agronomically superior to resistant cultivars or be better accepted by growers for other reasons. Hence, if mixtures with only a moderate proportion of the resistant cultivar provide a similar degree of disease control as resistant pure stands, as our analysis indicates, such mixtures are more likely to be accepted by growers.

scholarly journals Behavior of Spanish durum wheat genotypes against Zymoseptoria tritici: resistance and susceptibility

2021 ◽  
Vol 19 (3) ◽  
pp. e1002-e1002
Author(s):  
Rafael Porras ◽  
Keyword(s):  
Durum Wheat ◽  
Agronomic Traits ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Sources Of Resistance ◽  
Breeding Lines ◽  
Wheat Genotypes ◽  
Commercial Cultivars ◽  
Growth Chambers

Aim of study: Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici, is one of the most important wheat diseases worldwide, affecting both bread and durum wheat. The lack of knowledge about the interaction of durum wheat with Z. tritici, together with limited resources of resistant durum wheat material, have both led to a rising threat for durum wheat cultivation, particularly in the Mediterranean Basin. In Spain, STB has increased its incidence in the last few years, leading to higher costs of fungicide applications to control the disease. Therefore, identification of new sources of resistance through wheat breeding stands out as an efficient method of facing STB. Area of study: The experimental study was conducted in growth chambers at the IFAPA facilities in Córdoba (Spain). Material and methods: The percentage of necrotic leaf area, the disease severity, and the pycnidium development through image analysis were evaluated from 48 durum wheat Spanish accessions (breeding lines and commercial cultivars) in growth chambers against an isolate of Z. tritici from Córdoba. Main results: Two breeding lines and six commercial cultivars showed resistant responses by limiting STB development through the leaf or its reproduction ability, while the other 40 accessions presented a susceptible response. Research highlights: Provided these resources of resistance in Spanish durum wheat genotypes, future breeding programs could be developed, incorporating both agronomic traits and resistance to STB.

scholarly journals SNP-Based Genetic Structure of Tunisian Durum Wheat Landraces and Distribution of the Resistance to Septoria Tritici Blotch

2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa M. Sri ◽  
...  
Keyword(s):  
Population Structure ◽  
Durum Wheat ◽  
Eastern Mediterranean ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Mediterranean Populations ◽  
Population Structure Analysis ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.

scholarly journals First Report of Resistance to QoI Fungicides in North American Populations of Zymoseptoria tritici, Causal Agent of Septoria Tritici Blotch of Wheat

Plant Disease ◽  
2013 ◽  
Vol 97 (11) ◽  
pp. 1511-1511 ◽  
Author(s):  
L. K. Estep ◽  
M. Zala ◽  
N. P. Anderson ◽  
K. E. Sackett ◽  
M. Flowers ◽  
...  
Keyword(s):  
De Novo ◽  
Flag Leaf ◽  
Causal Agent ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Cellular Respiration ◽  
Zymoseptoria Tritici ◽  
Science Field ◽  
Qoi Fungicides ◽  
Wheat Field

The G143A mutation in cytb (cytochrome b gene) is associated with high levels of resistance to quinone outside inhibitor (QoI or strobilurin) fungicides that disrupt electron transport during cellular respiration (1). The G143A mutation in Zymoseptoria tritici (synonyms: Mycosphaerella graminicola and Septoria tritici), the causal agent of septoria tritici blotch of wheat (Triticum aestivum), was first reported in Europe in 2001 (1). Although Z. tritici has a global distribution (3), G143A mutants of Z. tritici have not been reported outside of Europe. We used PCR-RFLP (4) to estimate the frequencies of G143A mutants in Z. tritici populations at two locations in the Willamette Valley of western Oregon: the Hyslop Crop Science Field Research Laboratory (Hyslop Farm, HF), Benton County (44°37′52.85″ N, 123°11′55.19″ W) and research plots planted in a commercial wheat field in Washington County (45°33′58.53″ N, 123°00′11.78″ W) (North Valley Farm, NVF). Isolates originated from flag leaf collections from two cultivars (‘Bobtail’ and ‘Tubbs 06’) made in April and June of 2012 from plants in a replicated fungicide-treatment experiment, with isolates collected from both sprayed and unsprayed plots. Sixteen of the 169 isolates (9.5%) from HF possessed the G143A mutation (7 of 132 isolates from plots not receiving a QoI fungicide and 9 of 37 isolates collected from plots receiving two applications of the QoI azoxystrobin). One hundred forty six of the 175 isolates (83.4%) from NVF were G143A mutants (101 of 129 isolates from plots receiving no QoI fungicide and 45 of 46 isolates from plots receiving two applications of azoxystrobin). Results of phenotypic assays of a subset of 10 isolates from each location (5 mutants, 5 wild types from each location; 20 isolates altogether) supported a high level of resistance to azoxystrobin only in the G143A mutants. All 10 G143A mutants developed colonies after 8 days of growth on YMA plates amended with SHAM (2) and 1 ppm or 10 ppm azoxystrobin, with nine and eight G143A mutant isolates developing colonies on plates amended with 1 ppm and 10 ppm azoxystrobin, respectively. None of the wild-type isolates developed colonies on plates amended with SHAM and 1 ppm azoxystrobin, nor on plates amended with SHAM and 10 ppm azoxystrobin. All 20 isolates developed colonies on YMA plates lacking azoxystrobin, and treatments produced identical results across three replicates. These results are consistent with findings of higher levels of azoxystrobin resistance in G143A mutants compared to wild types in European populations (1). Isolates from HF and NVF differ in their previous exposure to QoI fungicides. The majority of the wheat area at HF is planted to breeding plots that are not sprayed with fungicide. Plots at NVF were planted in a commercial wheat field in a county where most wheat fields were treated with two to three applications of strobilurins each year over the past 4 years. Future monitoring for G143A mutants of Z. tritici throughout its range in North America will be necessary to assess whether strobilurin resistance will spread via wind-dispersal of ascospores or emerge de novo in treated fields. In Europe, stobilurins were first applied to wheat in 1996. G143A mutants of Z. tritici emerged de novo several times (4) and were widespread by 2007. References: (1) B. A. Fraaje et al. Phytopathology 95:933, 2005. (2) J. A. LaMondia. Tob. Sci. 49:1, 2012. (3) E. S. Orton et al. Mol. Plant Pathol. 12:413, 2011. (4) S. F. F. Torriani et al. Pest Manag. Sci. 65:155, 2008.

scholarly journals Evaluation of Efficacy and Compatibility of Herbicides with Fungicides in Durum Wheat (Triticum durum Desf.) under Different Environmental Conditions: Effects on Grain Yield and Gluten Content

2018 ◽  
Vol 46 (2) ◽  
pp. 601-607 ◽  
Author(s):  
Anestis Christos KARKANIS ◽  
Evangelos VELLIOS ◽  
Filippos GRIGORIOU ◽  
Theodoros GKRIMPIZIS ◽  
Persephoni GIANNOULI
Keyword(s):  
Durum Wheat ◽  
Field Experiments ◽  
Stem Elongation ◽  
Temperature Fluctuations ◽  
Cold Temperatures ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Arid Conditions ◽  
Triticum Durum Desf ◽  
Semi Arid

In the present study, field experiments were conducted to determine the efficacy and compatibility of herbicides and fungicides in durum wheat under Mediterranean semi-arid conditions, in Central Greece. Our results indicate that the herbicide florasulam+2.4-D was safe and did not cause any injury when applied alone or with fungicides, while bromoxynil+2.4-D mixed with azoxystrobin or trifloxystrobin+prothioconazole caused injury symptoms on leaves. The injury symptoms were transient, and observed only at Velestino area, where low temperatures and broad diurnal temperature fluctuations were recorded during the pesticides application period. Regarding septoria leaf blotch control, good results showed strobilurin alone or in mixture with a triazole, regardless the herbicide that was added to the mixture. The results of this study showed that bromoxynil+2.4-D caused injury when mixed with fungicides and applied under cold temperatures, while one fungicide application at stem elongation provided adequate Septoria leaf blotch control.

scholarly journals SNP-based Genetic Structure of Tunisian Durum Wheat Landraces and Distribution of the Resistance to Septoria Tritici Blotch

2021 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Bahri ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
Udupa . Sripa ◽  
...  
Keyword(s):  
Population Structure ◽  
Durum Wheat ◽  
Eastern Mediterranean ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Mediterranean Populations ◽  
Population Structure Analysis ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

Abstract Background: Septoria tritici blotch (STB) has marked durum wheat production worldwide. This fungal disease is until today a challenge for farmers, researchers and breeders all united in the aim of reducing its damage and improving wheat resistance. Tunisian durum wheat landraces were reported to be valuable genetic resources for resistance to biotic and abiotic stresses and are therefore prominently deployed in breeding programs to develop new varieties adapted to fungal diseases as STB and to climate change constraints overall.Results: A total of 366 local durum wheat accessions were assessed for resistance to two virulent Tunisian isolates of Zymoseptoria tritici Tun06 and TM220 under field conditions. Population structure analysis of the durum wheat accessions, performed with 286 polymorphic SNPs (PIC >0.3) covering the entire genome, identified three genetic subpopulations (GS1, GS2 and GS3) with 22% of admixed genotypes. Interestingly, all of the resistant genotypes were among GS2 or admixed with GS2. Conclusions: This study revealed the population structure and the genetic distribution of the resistance to Z. tritici in the Tunisian durum wheat landraces. The grouping pattern of accessions appear to be associated, to some extent, with the geographical pattern of the landraces. We suggested that GS2 accessions were mostly introduced from eastern Mediterranean populations, unlike GS1 and GS3 that originated from the west. Resistant GS2 accessions belonged to landraces Taganrog, Sbei glabre, Richi, Mekki, Badri, Jneh Khotifa and Azizi. Furthermore, we suggested that admixture contributed to transmit STB resistance from GS2 resistant landraces to initially susceptible landraces such as Mahmoudi (GS1), but also resulted in the loss of resistance in the case of GS2 suscpetible Azizi and Jneh Khotifa accessions.

Microsatellite markers provide evidence for sexual reproduction of Mycosphaerella graminicola in Saskatchewan

Genome ◽  
2004 ◽  
Vol 47 (5) ◽  
pp. 789-794 ◽  
Author(s):  
M Razavi ◽  
G R Hughes
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Sexual Reproduction ◽  
Primary Source ◽  
Mycosphaerella Graminicola ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Allelic Series ◽  
Evolutionary Potential ◽  
Wheat Field

This study examined the genetic structure of a Saskatchewan population of Mycosphaerella graminicola, cause of the foliar disease Septoria tritici blotch of wheat. Such knowledge is valuable for understanding the evolutionary potential of this pathogen and for developing control strategies based on host resistance. Nine pairs of single-locus microsatellite primers were used to analyze the genomic DNA of 90 isolates of M. graminicola that were collected using a hierarchical sampling procedure from different locations, leaves, and lesions within a wheat field near Saskatoon. Allelic series at eight different loci were detected. The number of alleles per locus ranged from one to five with an average of three alleles per locus. Genetic diversity values ranged from 0.04 to 0.67. Partitioning the total genetic variability into within- and among-location components revealed that 88% of the genetic variability occurred within locations, i.e., within areas of 1 m2, but relatively little variability occurred among locations. Low variability among locations and a high degree of variability within locations would result if the primary source of inoculum was airborne ascospores, which would be dispersed uniformly within the field. This finding was confirmed by gametic disequilibrium analysis and suggests that the sexual reproduction of M. graminicola occurs in Saskatchewan.Key words: Mycosphaerella graminicola, SSR markers, sexual reproduction, genetic diversity.

scholarly journals Characterisation of an antimicrobial and phytotoxic ribonuclease secreted by the fungal wheat pathogen Zymoseptoria tritici

2017 ◽  
Author(s):  
Graeme J. Kettles ◽  
Carlos Bayon ◽  
Caroline A. Sparks ◽  
Gail Canning ◽  
Kostya Kanyuka ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Effector Proteins ◽  
Yeast Cells ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
List Type ◽  
Expression Systems ◽  
Zymoseptoria Tritici ◽  
Loop Region

Abstract-The fungus Zymoseptoria tritici is the causal agent of Septoria Tritici Blotch (STB) disease of wheat leaves. Z. tritici secretes many functionally uncharacterised effector proteins during infection. Here we characterised a secreted ribonuclease (Zt6) with an unusual biphasic expression pattern.-Transient expression systems were used to characterise Zt6, and mutants thereof, in both host and non-host plants. Cell-free protein expression systems monitored impact of Zt6 protein on functional ribosomes, and in vitro assays of cells treated with recombinant Zt6 determined toxicity against bacteria, yeasts and filamentous fungi.-We demonstrated that Zt6 is a functional ribonuclease and that phytotoxicity is dependent on both the presence of a 22-amino acid N-terminal “loop” region and its catalytic activity. Zt6 selectively cleaves both plant and animal rRNA species, and is toxic to wheat, tobacco, bacterial and yeast cells but not to Z. tritici itself.-Zt6 is the first Z. tritici effector demonstrated to have a likely dual functionality. The expression pattern of Zt6 and potent toxicity towards microorganisms suggests that whilst it may contribute to the execution of wheat cell death, it is also likely to have an important secondary function in antimicrobial competition and niche protection.

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