scholarly journals One gene-one name: the AvrLmJ1 avirulence gene of Leptosphaeria maculans is AvrLm5

2017 ◽  
Vol 19 (4) ◽  
pp. 1012-1016 ◽  
Author(s):  
Clémence Plissonneau ◽  
Thierry Rouxel ◽  
Anne-Marie Chèvre ◽  
Angela P. Van De Wouw ◽  
Marie-Hélène Balesdent
2002 ◽  
Vol 15 (7) ◽  
pp. 672-682 ◽  
Author(s):  
Agnès Attard ◽  
Lilian Gout ◽  
Mathieu Gourgues ◽  
Marie-Line Kühn ◽  
Jacques Schmit ◽  
...  

Map-based cloning of the avirulence gene AvrLm1 of Leptosphaeria maculans was initiated utilizing a genetic map of the fungus and a BAC library constructed from an AvrLm1 isolate. Seven polymorphic DNA markers closely linked to AvrLm1 were identified. Of these, two were shown to border the locus on its 5′ end and were present, with size polymorphism, in both the virulent and the avirulent isolates. In contrast, three markers, J19-1.1, J53-1.3 (in coupling phase with avirulence), and Vir1 (in repulsion phase with avirulence), cosegregated with AvrLm1 in 312 progeny from five in vitro crosses. J19-1.1 and J53-1.3 were never amplified in the virulent parents or progeny, whereas Vir1 was never amplified in the avirulent parents or progeny. J19-1.1 and J53-1.3 were shown to be separated by 40 kb within a 184-kb BAC contig. In addition, the 1.6-cM genetic distance between J53-1.3 and the nearest recombinant marker corresponded to a 121-kb physical distance. When analyzing a European Union-wide collection of 192 isolates, J53-1.3, J19-1.1, and Vir1 were found to be closely associated with the AvrLm1 locus. The results of polymerase chain reaction amplification with primers for the three markers were in accordance with the interaction phenotype for 92.2% (J53-1.3), 90.6% (J19-1.1), and 88.0% (Vir1) of the isolates. In addition, genome organization of the AvrLm1 region was highly conserved in field isolates, because 89.1% of the avirulent isolates and 79.0% of the virulent isolates showed the same association of markers as that of the parents of in vitro crosses. The large-scale analysis of field isolates with markers originating from the genetic map therefore confirms (i) the physical proximity between the markers and the target locus and (ii) that AvrLm1 is located in (or close to) a recombination-deficient genome region. As a consequence, map-based markers provided us with high-quality markers for an overview of the occurrence of race “AvrLm1” at the field scale. These data were used to propose hypotheses on evolution towards virulence in field isolates.


1998 ◽  
Vol 88 (10) ◽  
pp. 1068-1072 ◽  
Author(s):  
Patchara Pongam ◽  
Thomas C. Osborn ◽  
Paul H. Williams

A gene-for-gene interaction was previously suggested by mapping of a single major locus (LEM 1) controlling cotyledon resistance to Leptosphaeria maculans isolate PHW1245 in Brassica napus cv. Major. In this study, we obtained further evidence of a gene-for-gene interaction by studying the inheritance of the corresponding avirulence gene in L. maculans isolate PHW1245. The analysis of segregating F1 progenies and 14 test crosses suggested that a single major gene is involved in the interaction. This putative avirulence gene was designated alm1 after the resistance locus identified in B. napus. Amplified fragment length polymorphism (AFLP) markers were used to generate a rudimentary genetic linkage map of the L. maculans genome and to locate markers linked to the putative avirulence locus. Two flanking AFLP markers, AC/TCC-1 and AC/CAG-5, were linked to alm1 at 3.1 and 8.1 cM, respectively. Identification of markers linked to the avirulence gene indicated that the differential interaction is controlled by a single gene difference between parental isolates and provides further support for the gene-for-gene relationship in the Leptosphaeria-Brassica system.


2011 ◽  
Vol 124 (3) ◽  
pp. 505-513 ◽  
Author(s):  
Kaveh Ghanbarnia ◽  
Derek J. Lydiate ◽  
S. Roger Rimmer ◽  
Genyi Li ◽  
H. Randy Kutcher ◽  
...  

2001 ◽  
Vol 91 (1) ◽  
pp. 70-76 ◽  
Author(s):  
M. H. Balesdent ◽  
A. Attard ◽  
D. Ansan-Melayah ◽  
R. Delourme ◽  
M. Renard ◽  
...  

Leptosphaeria maculans causes blackleg of oilseed rape. Gene-for-gene interactions between race PG3 and Brassica napus cv. Quinta were related to interaction between the fungal avirulence (Avr) gene AvrLm1 and the corresponding resistance gene Rlm1. AvrLm1 isolates were aviru-lent on cvs. Doublol, Vivol, Columbus, and Capitol, and no recombinant phenotypes were observed in the progeny of two AvrLm1 × avrLm1 crosses, suggesting that all of these cultivars may possess Rlm1 or genes displaying the same recognition spectrum, or that a cluster of Avr genes is present at the Avrlm1 locus. In one cross, segregation distortion was observed at the AvrLm1 locus that could be explained by interaction between AvrLm1 and one unlinked deleterious gene, termed Del1. Incompatibility toward cvs. Jet Neuf and Darmor.bzh was governed by a single gene, unlinked to AvrLm1 or Del1. This avirulence gene was termed AvrLm4. Preliminary plant genetic analysis suggested the occurrence of a corresponding dominant resistance gene, termed Rlm4, present in the Quinta line analyzed and linked to Rlm1.


2020 ◽  
Author(s):  
Ting Xiang Neik ◽  
Kaveh Ghanbarnia ◽  
Bénédicte Ollivier ◽  
Armin Scheben ◽  
Anita Severn-Ellis ◽  
...  

SummaryLeptosphaeria maculans, the causal agent of blackleg disease, interacts with Brassica napus (oilseed rape, canola) in a gene-for-gene manner. The avirulence genes AvrLmS and AvrLep2 were described to be perceived by the resistance genes RlmS and LepR2, respectively, present in the cultivar Surpass 400. Here we report cloning of AvrLmS and AvrLep2 using two independent methods. AvrLmS was cloned using combined in vitro crossing between avirulent and virulent isolates with sequencing of DNA bulks from avirulent or virulent progeny (Bulked-Segregant-Sequencing) to rapidly identify one candidate avirulence gene present in the effector repertoire of L. maculans. AvrLep2 was cloned using a bi-parental cross of avirulent and virulent L. maculans isolates and a classical map-based cloning approach. Taking these two approaches independently, we found that AvrLmS and AvrLep2 are the same gene. Complementation of virulent isolates with this gene confirmed its role in inducing resistance on Surpass 400 and Topas-LepR2. The gene renamed AvrLmS-Lep2 encodes for a small cysteine-rich protein of unknown function with an N-terminal secretory signal peptide, which are common features of the majority of effectors from extracellular fungal plant pathogens. The AvrLmS-Lep2 / LepR2 interaction phenotype was found to vary from a typical hypersensitive response to intermediate resistance sometimes at the edge of, or evolving toward, susceptibility depending on the inoculation conditions. AvrLmS-Lep2 was nevertheless sufficient to significantly reduce the stem lesion size on plant genotypes with LepR2, indicating the potential efficiency of this resistance to control the disease in the field.


2012 ◽  
Vol 25 (9) ◽  
pp. 1238-1250 ◽  
Author(s):  
Vladimír Šašek ◽  
Miroslava Nováková ◽  
Barbora Jindřichová ◽  
Károly Bóka ◽  
Olga Valentová ◽  
...  

Interaction of a plant with a fungal pathogen is an encounter with hundreds of molecules. In contrast to this, a single molecule often decides between the disease and resistance. In the present article, we describe the defense responses triggered by AvrLm1, an avirulence gene from a hemibiotrophic ascomycete, Leptosphaeria maculans, responsible for an incompatible interaction with Brassica napus. Using multiple hormone quantification and expression analysis of defense-related genes, we investigated signaling events in Rlm1 plants infected with two sister isolates of L. maculans differentiated by the presence or absence of AvrLm1. Infection with the isolate carrying AvrLm1 increased the biosynthesis of salicylic acid (SA) and induced expression of the SA-associated genes ICS1, WRKY70, and PR-1, a feature characteristic of responses to biotrophic pathogens and resistance gene–mediated resistance. In addition to SA-signaling elements, we also observed the induction of ASC2a, HEL, and CHI genes associated with ethylene (ET) signaling. Pharmacological experiments confirmed the positive roles of SA and ET in mediating resistance to L. maculans. The unusual cooperation of SA and ET signaling might be a response to the hemibiotrophic nature of L. maculans. Our results also demonstrate the profound difference between the natural host B. napus and the model plant Arabidopsis in their response to L. maculans infection.


2013 ◽  
Vol 15 (5) ◽  
pp. 523-530 ◽  
Author(s):  
Angela P. Van de Wouw ◽  
Rohan G. T. Lowe ◽  
Candace E. Elliott ◽  
David J. Dubois ◽  
Barbara J. Howlett

2019 ◽  
Author(s):  
Nicholas J. Larkan ◽  
Lisong Ma ◽  
Parham Haddadi ◽  
Miles Buchwaldt ◽  
Isobel A. P. Parkin ◽  
...  

AbstractIn plants, race-specific defense against microbial pathogens is facilitated by resistance (R) genes which correspond to specific pathogen avirulence (Avr) genes. This study reports the cloning of a blackleg R gene from Brassica napus (canola); Rlm9, which encodes a wall-associated kinase-like (WAKL) protein, a newly-discovered class of race-specific plant RLK resistance genes. Rlm9 provides race-specific resistance against isolates of Leptosphaeria maculans carrying the corresponding avirulence gene AvrLm5-9, representing only the second WAKL-type R gene described to date. The Rlm9 protein is predicted to be cell membrane-bound yet appears to have no direct interaction with AvrLm5-9. Rlm9 forms part of a distinct evolutionary family of RLK proteins in B. napus, and while little is yet known about WAKL function, the Brassica-Leptosphaeria pathosystem may prove to be a model system by which the mechanism of fungal avirulence protein recognition by WAKL-type R genes can be determined.


2006 ◽  
Vol 60 (1) ◽  
pp. 67-80 ◽  
Author(s):  
Lilian Gout ◽  
Isabelle Fudal ◽  
Marie-Line Kuhn ◽  
Francoise Blaise ◽  
Maria Eckert ◽  
...  

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