scholarly journals Analysis of Host Species Specificity of Magnaporthe grisea Toward Wheat Using a Genetic Cross Between Isolates from Wheat and Foxtail Millet

2000 ◽  
Vol 90 (10) ◽  
pp. 1060-1067 ◽  
Author(s):  
J. Murakami ◽  
Y. Tosa ◽  
T. Kataoka ◽  
R. Tomita ◽  
J. Kawasaki ◽  
...  
Keyword(s):  
Host Species ◽  
Magnaporthe Grisea ◽  
Foxtail Millet ◽  
Hypersensitive Reaction ◽  
Species Specificity ◽  
Genetic Cross ◽  
Genetic Mechanisms ◽  
Papilla Formation ◽  
Wheat Leaves

A genetic cross was performed between a Setaria isolate (pathogenic on foxtail millet) and a Triticum isolate (pathogenic on wheat) of Magnaporthe grisea to elucidate genetic mechanisms of its specific parasitism toward wheat. A total of 80 F1 progenies were obtained from 10 mature asci containing 8 ascospores. Lesions on wheat leaves produced by the F1 progenies were classified into four types, which segregated in a 1:1:1:1 ratio. This result suggested that the pathogenicity of the F1 population on wheat was controlled by two genes located at different loci. This idea was supported by backcross analyses. We designated these loci as Pwt1 and Pwt2. Cytological analyses revealed that Pwt1 and Pwt2 were mainly associated with the hypersensitive reaction and papilla formation, respectively.

scholarly journals Analysis of Host Species Specificity of Magnaporthe grisea Toward Foxtail Millet Using a Genetic Cross Between Isolates from Wheat and Foxtail Millet

2003 ◽  
Vol 93 (1) ◽  
pp. 42-45 ◽  
Author(s):  
J. Murakami ◽  
R. Tomita ◽  
T. Kataoka ◽  
H. Nakayashiki ◽  
Y. Tosa ◽  
...  
Keyword(s):  
Host Species ◽  
Magnaporthe Grisea ◽  
Foxtail Millet ◽  
Species Specificity ◽  
The Other ◽  
Single Locus ◽  
Gene Interactions ◽  
Genetic Cross ◽  
Genetic Mechanisms ◽  
Cultivar Specificity

Host species specificity of Magnaporthe grisea toward foxtail millet was analyzed using F1 cultures derived from a cross between a Triticum isolate (pathogenic on wheat) and a Setaria isolate (pathogenic on foxtail millet). On foxtail millet cvs. Beni-awa and Oke-awa, avirulent and virulent cultures segregated in a 1:1 ratio, suggesting that a single locus is involved in the specificity. This locus was designated as Pfm1. On cv. Ki-awa, two loci were involved and one of them was Pfm1. The other locus was designated as Pfm2. Interestingly, Pfm1 was not involved in the pathogenic specificity on cv. Kariwano-zairai. These results suggest that there is no “master gene” that determines the pathogenic specificity on all foxtail millet cultivars and that the species specificity of M. grisea toward foxtail millet is governed by cultivar-dependent genetic mechanisms that are similar to gene-for-gene interactions controlling race-cultivar specificity.

Characterization of an Avena isolate of Magnaporthe grisea and identification of a locus conditioning its specificity on oat

2002 ◽  
Vol 80 (10) ◽  
pp. 1088-1095 ◽  
Author(s):  
H S Oh ◽  
Y Tosa ◽  
N Takabayashi ◽  
S Nakagawa ◽  
R Tomita ◽  
...  
Keyword(s):  
Magnaporthe Grisea ◽  
Single Gene ◽  
Severe Disease ◽  
Hypersensitive Reaction ◽  
Temperature Sensitive ◽  
Rdna Its ◽  
Genetic Mechanisms ◽  
Pathogenicity Tests ◽  
Wheat Leaves ◽  
Species Specific

An isolate of Magnaporthe grisea was collected from a blast lesion on oat in Brazil. Sequence analysis of the rDNA-ITS-2 region and DNA fingerprinting with repetitive elements revealed that the Avena isolate belongs to the "crop isolate group" and is similar to Triticum isolates. At high temperature (28°C), the Avena isolate caused severe disease symptoms on primary leaves of oat and wheat. When the temperature was decreased to 20°C, wheat leaves expressed resistance to the Avena isolate. Cytologically, this temperature-dependent resistance was associated with an increase in the incidences of papilla formation and a hypersensitive reaction. Pathogenicity tests with various plant species at 20°C revealed that the Avena isolate is exclusively parasitic on oat. To elucidate genetic mechanisms of this species-specific parasitism, the Avena isolate was crossed with a Triticum isolate and resulting F1 progenies were subjected to pathogenicity tests on oat seedlings. In the F1 population, avirulent and virulent cultures segregated in a 1:1 ratio, suggesting that the specific parasitism on oat is controlled by a single gene. This locus was designated as Pat1.Key words: Magnaporthe grisea, species-specific parasitism, oat, temperature sensitive.

scholarly journals Genetic Analysis of Host Species Specificity of Magnaporthe oryzae Isolates from Rice and Wheat

2006 ◽  
Vol 96 (5) ◽  
pp. 480-484 ◽  
Author(s):  
Y. Tosa ◽  
H. Tamba ◽  
K. Tanaka ◽  
S. Mayama
Keyword(s):  
Genetic Analysis ◽  
Magnaporthe Oryzae ◽  
Host Species ◽  
Hypersensitive Reaction ◽  
Species Specificity ◽  
The Other ◽  
Papilla Formation ◽  
Allelism Tests

A Triticum isolate (pathogenic on wheat) of Magnaporthe oryzae was crossed with an Oryza isolate (pathogenic on rice) to elucidate mechanisms of their parasitic specificity on wheat. When the pathogenicity of their F 1 cultures (hybrids between a Triticum isolate and an Oryza isolate) was tested on wheat, avirulent and virulent cultures segregated in a 7:1 ratio. This result suggests that three loci are involved in avirulence of the Oryza isolate on wheat. One of the three loci conditioned papilla formation, whereas the others conditioned the hypersensitive reaction. Allelism tests revealed that the locus conditioning papilla formation is Pwt2 while one of the two loci conditioning the hypersensitive reaction is Pwt1. The other locus conditioning the hypersensitive reaction was different from any other known loci and, therefore, was designated as Pwt5.

Genetic analysis and molecular mapping of the avirulence gene PRE1, a gene for host-species specificity in the blast fungus Magnaporthe grisea

Genome ◽  
2006 ◽  
Vol 49 (8) ◽  
pp. 873-881 ◽  
Author(s):  
Q H Chen ◽  
Y C Wang ◽  
X B Zheng
Keyword(s):  
Genetic Analysis ◽  
Ssr Markers ◽  
Host Species ◽  
Magnaporthe Grisea ◽  
Species Specificity ◽  
Avirulence Gene ◽  
Chromosome 3 ◽  
Genetic Linkage Analysis ◽  
Genetic Mechanisms ◽  
Species Specific

We analyzed host-species specificity of Magnaporthe grisea on rice using 110 F1 progeny derived from a cross between the Oryza isolate CH87 (pathogenic to rice) and the Digitaria isolate 6023 (pathogenic to crabgrass). To elucidate the genetic mechanisms controlling species specificity in M. grisea, we performed a genetic analysis of species-specific avirulence on this rice population. Avirulent and virulent progeny segregated in a 1:1 ratio on the 2 rice cultivars 'Lijiangxintuanheigu' (LTH) and 'Shin2', suggesting that a single locus, designated PRE1, was involved in the specificity. In a combination between 'Kusabue' and 'Tsuyuake', the segregation of the 4 possible phenotypes of F1 progeny was significantly different from the expected 3:1:3:1 and instead fit a ratio of 2:0:1:1. This indicated that 2 loci, PRE1 and AVR2, were involved in specific parasitism on rice. These results suggest that the species specificity of M. grisea on rice is governed by species-dependent genetic mechanisms that are similar to the gene-for-gene interactions controlling cultivar specificity. Pathogenicity tests with various plant species revealed that the Digitaria isolate 6023 was exclusively parasitic on crabgrass. Genetic linkage analysis showed that PRE1 was mapped on chromosome 3 with respect to RAPD and SSR markers. RAPD marker S361 was linked to the avirulence gene at a distance of ~6.4 cM. Two SSR markers, m677–678 and m77–78, were linked to the PRE1 gene on M. grisea chromosome 3 at distances of 5.9 and 7.1 cM, respectively. Our results will facilitate positional cloning and functional studies of this gene.Key words: genetic analysis, graminaceous plants, Magnaporthe grisea, species-specific avirulence gene.

scholarly journals The barley immune receptor Mla recognizes multiple pathogens and contributes to host range dynamics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jan Bettgenhaeuser ◽  
Inmaculada Hernández-Pinzón ◽  
Andrew M. Dawson ◽  
Matthew Gardiner ◽  
Phon Green ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Stripe Rust ◽  
Resistance Genes ◽  
Host Species ◽  
Plant Pathogens ◽  
Puccinia Striiformis ◽  
Species Specificity ◽  
Wheat Stripe Rust ◽  
Barley Powdery Mildew ◽  
Barley Stripe Rust

AbstractCrop losses caused by plant pathogens are a primary threat to stable food production. Stripe rust (Puccinia striiformis) is a fungal pathogen of cereal crops that causes significant, persistent yield loss. Stripe rust exhibits host species specificity, with lineages that have adapted to infect wheat and barley. While wheat stripe rust and barley stripe rust are commonly restricted to their corresponding hosts, the genes underlying this host specificity remain unknown. Here, we show that three resistance genes, Rps6, Rps7, and Rps8, contribute to immunity in barley to wheat stripe rust. Rps7 cosegregates with barley powdery mildew resistance at the Mla locus. Using transgenic complementation of different Mla alleles, we confirm allele-specific recognition of wheat stripe rust by Mla. Our results show that major resistance genes contribute to the host species specificity of wheat stripe rust on barley and that a shared genetic architecture underlies resistance to the adapted pathogen barley powdery mildew and non-adapted pathogen wheat stripe rust.

Increased Lipoxygenase Activity is Involved in the Hypersensitive Response of Wheat Leaf Cells Infected with A virulent Rust Fungi or Treated with Fungal Elicitor

1986 ◽  
Vol 41 (5-6) ◽  
pp. 559-563 ◽  
Author(s):  
Carlos A. Ocampo ◽  
Bruno Moerschbacher ◽  
Hans J. Grambow
Keyword(s):  
Hypersensitive Response ◽  
Hypersensitive Reaction ◽  
Rust Fungi ◽  
Lipoxygenase Activity ◽  
Puccinia Graminis ◽  
Compatible Interaction ◽  
Wheat Leaf ◽  
Wheat Leaves ◽  
Germ Tubes ◽  
Wheat Rust

The hypersensitive reaction in incompatible wheat-rust interactions is characterized by an increase in lipoxygenase activity detectable as early as 28 h after penetration of the pathogen. In contrast, lipoxygenase activity in the compatible interaction did not increase until the onset of sporulation.Lipoxygenase activity also increased following treatment of wheat leaves with an elicitor fraction from germ tubes of Puccinia graminis tritici.

scholarly journals Identification, cloning, and characterization of PWL2, a gene for host species specificity in the rice blast fungus.

1995 ◽  
Vol 7 (8) ◽  
pp. 1221-1233 ◽  
Author(s):  
J A Sweigard ◽  
A M Carroll ◽  
S Kang ◽  
L Farrall ◽  
F G Chumley ◽  
...  
Keyword(s):  
Host Species ◽  
Rice Blast ◽  
Rice Blast Fungus ◽  
Species Specificity ◽  
Blast Fungus

scholarly journals A Gene-for-Gene Relationship Underlying the Species-Specific Parasitism of Avena/Triticum Isolates of Magnaporthe grisea on Wheat Cultivars

2002 ◽  
Vol 92 (11) ◽  
pp. 1182-1188 ◽  
Author(s):  
N. Takabayashi ◽  
Y. Tosa ◽  
H. S. Oh ◽  
S. Mayama
Keyword(s):  
Resistance Gene ◽  
Temperature Sensitivity ◽  
Chinese Spring ◽  
Magnaporthe Grisea ◽  
Gene Interactions ◽  
Wheat Cultivars ◽  
Genetic Mechanisms ◽  
Species Specific ◽  
Cultivar Specificity ◽  
Gene For Gene

To elucidate genetic mechanisms of the species-specific parasitism of Magnaporthe grisea, a Triticum isolate (pathogenic on wheat) was crossed with an Avena isolate (pathogenic on oat), and resulting F1 progeny were subjected to segregation analyses on wheat cvs. Norin 4 and Chinese Spring. We found two fungal loci, Pwt3 and Pwt4, which are involved in the specific parasitism on wheat. Pwt3 operated on both cultivars while Pwt4 operated only on ‘Norin 4’. Using the cultivar specificity of Pwt4, its corresponding resistance gene was successfully identified in ‘Norin 4’ and designated as Rmg1 (Rwt4). The presence of the corresponding resistance gene indicated that Pwt4 is an avirulence locus. Pwt3 was assumed to be an avirulence locus because of its temperature sensitivity. We suggest that gene-for-gene interactions underlie the species-specific parasitism of M. grisea.

Sign in / Sign up

Export Citation Format

Share Document