Inheritance And Allelic Relationship Of Resistance Genes To Spot Blotch Of Wheat Caused By Bipolaris Sorokiniana

2007 ◽  
pp. 113-118 ◽  
Author(s):  
S. Kumar ◽  
L. C. Prasad ◽  
U. Kumar ◽  
K. Tyagi ◽  
B. Arun ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Bipolaris Sorokiniana ◽  
Spot Blotch ◽  
Allelic Relationship ◽  
Relationship Of

scholarly journals rcs5-mediated spot blotch resistance in barley is conferred by wall-associated kinases that resist pathogen manipulation

2020 ◽  
Author(s):  
Gazala Ameen ◽  
Shyam Solanki ◽  
Thomas Drader ◽  
Lauren Sager-Bittara ◽  
Brian Steffenson ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Resistance Genes ◽  
Bipolaris Sorokiniana ◽  
Susceptibility Genes ◽  
Spot Blotch ◽  
Transcriptional Gene Silencing ◽  
Recessive Resistance ◽  
Barley Cultivars ◽  
Virulent Isolate

ABSTRACTPlant biotrophic pathogen disease resistances rely on immunity receptor-mediated programmed cell death (PCD) responses, but specialized necrotrophic/hemi-biotrophic pathogens hijack these mechanisms to colonize the resulting dead tissue in their necrotrophic phase. Thus, immunity receptors can become necrotrophic pathogen dominant susceptibility targets but resistance mechanisms that resist necrotroph manipulation are recessive resistance genes. The barley rcs5 QTL imparts recessive resistance against the disease spot blotch caused by the hemi-biotrophic fungal pathogen Bipolaris sorokiniana. The rcs5 genetic interval was delimited to ~0.23 cM, representing an ~234 kb genomic region containing four wall-associated kinase (WAK) genes, designated HvWak2, Sbs1, Sbs2 (susceptibility to Bipolaris sorokiniana1&2), and HvWak5. Post-transcriptional gene silencing of Sbs1&2 in susceptible barley cultivars resulted in resistance showing dominant susceptibility function. Allele analysis of Sbs1&2 from resistant and susceptible barley cultivars identified sequence polymorphisms associated with phenotypes in their primary coding sequence and promoter regions, suggesting differential transcriptional regulation may contribute to susceptibility. Transcript analysis of Sbs1&2 showed nearly undetectable expression in resistant and susceptible cultivars prior to pathogen challenge; however, upregulation of both genes occurred specifically in susceptible cultivars post-inoculation with a virulent isolate. Apoplastic wash fluids collected from barley infected with a virulent isolate induced Sbs1, suggesting regulation by an apoplastic-secreted effector. Thus, Sbs1&2 function as B. sorokiniana susceptibility targets and non-functional alleles or alleles that resist induction by the pathogen mediate rcs5-recessive resistance. The sbs1&2 alleles underlying the rcs5 QTL that the pathogen is unable to manipulate are the first resistance genes identified against spot blotch.SIGNIFICANCE STATEMENTThe rcs5 locus in barley confers a high level of seedling resistance and a moderate level of adult plant resistance to spot blotch. It is part of a complex that has provided durable spot blotch resistance in many North American barley cultivars (cv) for more than 50 years. Genetic characterization and positional cloning of rcs5 identified the dominant susceptibility genes, Sbs1 and Sbs2 (susceptibility to Bipolaris sorokiniana 1 and 2) as wall-associated kinases. These genes are hijacked by the hemibiotrophic pathogen in its necrotrophic phase to induce programmed cell death, facilitating disease development. We report the first spot blotch resistance/susceptibility genes cloned that function via alleles that cannot be specifically induced and hijacked by virulent isolates of the pathogen.

scholarly journals First report of Bipolaris sorokiniana causing spot blotch of lentil in Algeria

2021 ◽  
Vol 43 (2) ◽  
Author(s):  
M. El Amine Kouadri ◽  
A. Amine Bekkar ◽  
S. Zaim
Keyword(s):  
Bipolaris Sorokiniana ◽  
Spot Blotch ◽  
First Report

Characterization of elite bread wheat (Triticum aestivum L.) germplasm for spot blotch Bipolaris sorokiniana (Sacc.) Shoemaker resistance

2021 ◽  
pp. 1-8
Author(s):  
Deep Shikha ◽  
Chandani Latwal ◽  
Elangbam Premabati Devi ◽  
Anupama Singh ◽  
Pawan K. Singh ◽  
...  
Keyword(s):  
Abiotic Stress Tolerance ◽  
Bipolaris Sorokiniana ◽  
Triticum Aestivum L ◽  
Spot Blotch ◽  
Biotic And Abiotic Stress ◽  
Wheat Varieties ◽  
Effective Measure ◽  
Breeding Lines ◽  
Elite Breeding Lines ◽  
Germplasm Accessions

Abstract Genetic resources are of paramount importance for developing improved crop varieties, particularly for biotic and abiotic stress tolerance. Spot blotch (SB) is a destructive foliar disease of wheat prevalent in warm and humid regions of the world, especially in the eastern parts of South Asia. For the management of this disease, the most effective measure is the development of resistant cultivars. Thus, the present investigation was carried out to confirm SB resistance in 200 germplasm accessions based on phenotypic observations and molecular characterization. These elite breeding lines obtained from the International Centre for Maize and Wheat Improvement, Mexico, are developed deploying multiple parentages. These lines were screened for SB resistance in the field under artificially created epiphytotic conditions during 2014–15 and 2015–16 along with two susceptible checks (CIANO T79 and Sonalika) and two resistant checks (Chirya 3 and Francolin). Eighty-two out of 200 germplasm accessions were found resistant to SB and resistance in these lines was confirmed with a specific SSR marker Xgwm148. Three accessions, VORONA/CNO79, KAUZ*3//DOVE/BUC and JUP/BJY//URES/3/HD2206/HORK//BUC/BUL were observed possessing better resistance than the well-known SB-resistant genotype Chirya3. These newly identified resistant lines could be used by wheat breeders for developing SB-resistant wheat varieties.

scholarly journals Molecular Mapping of Loci Conferring Susceptibility to Spot Blotch and Resistance to Powdery Mildew in Barley Using the Sequencing-Based Genotyping Approach

2020 ◽  
Vol 110 (2) ◽  
pp. 440-446 ◽  
Author(s):  
Yueqiang Leng ◽  
Mingxia Zhao ◽  
Jason Fiedler ◽  
Antonín Dreiseitl ◽  
Shiaoman Chao ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Molecular Mapping ◽  
Recombinant Inbred Lines ◽  
Major Gene ◽  
Bipolaris Sorokiniana ◽  
Spot Blotch ◽  
Blumeria Graminis ◽  
Seedling Stage ◽  
Barley Cultivars ◽  
Trait Locus

Spot blotch (SB) caused by Bipolaris sorokiniana and powdery mildew (PM) caused by Blumeria graminis f. sp. hordei are two important diseases of barley. To map genetic loci controlling susceptibility and resistance to these diseases, a mapping population consisting of 138 recombinant inbred lines (RILs) was developed from the cross between Bowman and ND5883. A genetic map was constructed for the population with 852 unique single nucleotide polymorphism markers generated by sequencing-based genotyping. Bowman and ND5883 showed distinct infection responses at the seedling stage to two isolates (ND90Pr and ND85F) of Bipolaris sorokiniana and one isolate (Race I) of Blumeria graminis f. sp. hordei. Genetic analysis of the RILs revealed that one major gene (Scs6) controls susceptibility to Bipolaris sorokiniana isolate ND90Pr, and another major gene (Mla8) confers resistance to Blumeria graminis f. sp. hordei isolate Race I, respectively. Scs6 was mapped on chromosome 1H of Bowman, as previously reported. Mla8 was also mapped to the short arm of 1H, which was tightly linked but not allelic to the Rcs6/Scs6 locus. Quantitative trait locus (QTL) analysis identified two QTLs, QSbs-1H-P1 and QSbs-7H-P1, responsible for susceptibility to spot blotch caused by Bipolaris sorokiniana isolate ND85F in ND5883, which are located on chromosome 1H and 7H, respectively. QSbs-7H-P1 was mapped to the same region as Rcs5, whereas QSbs-1H-P1 may represent a novel allele conferring seedling stage susceptibility to isolate ND85F. Identification and molecular mapping of the loci for SB susceptibility and PM resistance will facilitate development of barley cultivars with resistance to the diseases.

scholarly journals First Report of Spot Blotch Caused by Bipolaris sorokiniana on Winter Rye in Kentucky

Plant Disease ◽  
2021 ◽  
Author(s):  
Danilo Neves ◽  
Bill Bruening ◽  
Carrie A Knott ◽  
Chad Lee ◽  
Carl Bradley
Keyword(s):  
Flag Leaf ◽  
Morphological Characteristics ◽  
Bipolaris Sorokiniana ◽  
Spot Blotch ◽  
Winter Rye ◽  
Glycerol Solution ◽  
Conidial Suspension ◽  
Potential Yield ◽  
First Report ◽  
Plastic Bag

The Kentucky distilling industry ranks as one of the state’s largest industries and continues to expand. In 2017, the Kentucky distilling industry was responsible for approximately $235 million in state and local tax revenues (Coomes and Kornstein, 2019). Rye (Secale cereale L.) grains are a vital component for production of some distilled spirits. Although winter rye is produced on relatively few hectares in Kentucky currently, a recent initiative has supported expanding production to help meet the growing demand of local distilleries. University of Kentucky winter rye research field trials were visited in Caldwell and Logan Counties, KY in May 2018, and in Fayette County, KY in May 2019. Leaves were collected that had dark brown, oval to irregular-shaped lesions with definite margins and yellow halos. Symptoms were present on approximately 50% to 80% of the flag leaves, with severity ranging from 5% to 30% of the flag leaf area affected. Leaves were surface-disinfested by soaking in a 2% NaOCl solution for 1 min and rinsed twice in sterilized water and then placed in a humidity chamber (plastic bag with moist paper towels) at room temperature (approximately 24°C) to induce fungal sporulation. Seventeen single-spore isolates were obtained and stored at -80°C in 15% glycerol solution. Isolates were grown on potato dextrose agar under 12 h cycles of white light/darkness for 5 days. Colonies were gray to black. Conidia that formed were mostly straight or slightly curved, dark olivaceous brown, 3-7 septate, and 41.0-90.4 × 15.2-29.3 µm. Based on the symptoms observed on the collected leaves and these morphological characteristics similar to those described by Chang and Hwang (2000) and Manamgoda et al. (2014), the fungus was tentatively identified as Bipolaris sorokiniana (Sorokin) Shoemaker. The sequence of internal transcribed spacer regions (ITS) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) were used to identify three isolates (18Bs004, 18Bs111 and 19Bs064) using primer ITS1/ITS4 (White et al. 1990) and GPD1/GPD2 (Berbee et al. 1999), respectively. The sequences were deposited in GenBank with accession numbers MT457817, MT457818 and MZ066635 for ITS sequences and MZ073644 to MZ073646 for GAPDH sequences. BLAST searches with ITS and GAPDH sequences matched 100% identity (344/344 bp and 515/515 bp for ITS and GAPDH sequences, respectively) to B. sorokiniana (GenBank accession No. MT254731 and MH844813, respectively). To prove pathogenicity, a conidial suspension (1 × 105 conidia/ml) was used to inoculate 15-day-old cultivar ‘Serafino’ winter rye plants in the greenhouse. Leaves of 8 plants were inoculated with 50 ml of the conidial suspension using a spray bottle. Plants were covered with a transparent plastic bag for 48 h, and symptoms were observed 10 days after inoculation. Leaf lesions, similar to those described above, were present on all inoculated plants, but no symptoms were observed on non-inoculated control plants. Bipolaris sorokiniana was reisolated from symptomatic leaves and the identity of the pathogen was confirmed based on the morphology previously described. To our knowledge, this is the first report of spot blotch caused by B. sorokiniana on winter rye in Kentucky, but B. sorokiniana has been reported on rye in the neighboring state of Virginia (Roane 2009). Kentucky produces approximately 150,000 and 4,000 ha of winter wheat (Triticum aestivum) and winter barley (Hordeum vulgare) annually, respectively, which are both known hosts of B. sorokiniana (Kumar et al. 2002). An isolate of B. sorokiniana from rye was reported by Ghazvini and Tekauz (2007) to be less virulent on barley differential lines. Further research is needed to better understand spot blotch distribution, susceptibility in winter rye cultivars, and potential yield and quality loss implications in winter rye production and end use. It is unknown how susceptible various winter rye cultivars grown in Kentucky are to spot blotch.

Clonal Variability and Its Relevance in Generation of New Pathotypes in the Spot Blotch Pathogen, Bipolaris sorokiniana

2007 ◽  
Vol 56 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Shree P. Pandey ◽  
Sandeep Sharma ◽  
R. Chand ◽  
P. Shahi ◽  
A. K. Joshi
Keyword(s):  
Bipolaris Sorokiniana ◽  
Spot Blotch ◽  
Clonal Variability

Detection of efflux pump genes in multiresistant Acinetobacter baumannii ST2 in Iran

2021 ◽  
Author(s):  
Zahra Meshkat ◽  
Himen Salimizand ◽  
Yousef Amini ◽  
Davood Mansury ◽  
Abolfazl Rafati Zomorodi ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Efflux Pump ◽  
Tetracycline Resistance ◽  
Genomic Diversity ◽  
Expression Level ◽  
Tetracycline Resistance Genes ◽  
Microdilution Method ◽  
Relationship Of ◽  
Repetitive Extragenic Palindromic Pcr

AbstractAcinetobacter baumannii, as a nosocomial pathogen has become a worldwide concern in recent years. In the current study, the resistance to tetracyclines and colistin were assessed in the isolates from different provinces of Iran.During the timeline of this study, a number of 270 isolates of A. baumannii were collected from tracheal aspirates, wounds, urine and blood cultures. The minimum inhibitory concentration (MIC) for tetracycline, doxycycline, minocycline, tigecycline and colistin were evaluated. Tetracycline resistance genes were assessed by PCR. The mean expression level of adeB, adeJ and adeG were assessed using semi quantitative Real-Time PCR. The clonal relationship of the isolates was evaluated by the repetitive extragenic palindromic PCR (REP-PCR), International Clonal (IC) Lineage Multiplex PCR and multilocus sequence typing (MLST) (Pasteur scheme) methods.The MIC by microdilution method showed that 87.5, 51.4, 28, 0.74 and 0% of the isolates were resistant to tetracycline, doxycycline, minocycline, tigecycline and colistin respectively. The prevalence of tetracycline resistance genes was 99.2, 99.2, 98, 86.7, 10, 3.33, 0.37, 0% for adeB, adeJ, adeG, tetB, tetA(39), tetA, tetM and tetH in tetracycline-resistant isolates. Moreover, the expression level of adeB, adeJ, adeG genes in tigecycline-nonsusceptible A. baumannii (TNAB) strain was higher compared to the tigecycline-susceptible A. baumannii (TSAB). A broad genomic diversity was revealed, but ST2 was the most prevalent ST. Our results indicated that tetracycline resistance in Iran is mediated by resistance-nodulation-cell division (RND) and tetB efflux pumps.

Functional analysis of SCD1 gene involved in pathogenicity of spot blotch disease of wheat causing fungus Bipolaris sorokiniana

2021 ◽  
Author(s):  
Kartar Singh ◽  
Rashmi Aggarwal ◽  
Praveen Kumar Verma ◽  
Sandhya Verma ◽  
Sapna Sharma ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Bipolaris Sorokiniana ◽  
Spot Blotch

scholarly journals Multiple Sclerosis in French Canadians: Evidence for HLA Class II Susceptibility and Resistance Genes

1990 ◽  
Vol 17 (4) ◽  
pp. 382-386 ◽  
Author(s):  
D.G. Haegert ◽  
M. Michaud ◽  
G.S. Francis
Keyword(s):  
Multiple Sclerosis ◽  
Resistance Genes ◽  
Rflp Analysis ◽  
Class Ii ◽  
Hla Class Ii ◽  
Extended Haplotype ◽  
Allele Specific ◽  
Relationship Of ◽  
The Relationship ◽  
Susceptibility And Resistance

ABSTRACT:HLA class II DRBI, DQB1 and DQA1 gene probes were used to study DNA from unrelated French Canadian multiple sclerosis (MS) patients and controls by restriction fragment length polymorphism (RFLP) analysis. An MS-associated and linked series of allele-specific RFLPs or allogenotypes was identified among this relatively homogeneous ethnic group; the allogenotypes include DRwl5, DQw6 and a DQA1 allogenotype termed DQαlb. An additional allogenotype which cross-hybridizes with DQA1 and is termed DQA2 upper (DQA2U), was shown not only to be part of the MS-associated extended haplotype, but also to be independently associated with MS in DRwl5-negative patients. Conversely a second DQA2 allogenotype, termed DQA2 lower (DQA2L) and a DQB1 allogenotype (DQw7) linked to DQA2L showed negative correlations with MS. It seems likely that the relationship of the HLA class II gene region to MS is complex and that MS susceptibility may reflect interaction between disease susceptibility and resistance genes.

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