One of Two Major Paralogs of AVR-Pita1 Is Functional in Japanese Rice Blast Isolates

We analyzed the avirulence gene AVR-Pita1 in Japanese rice blast isolates to determine how they gain virulence toward rice cultivars containing the Pita resistance gene. An avirulent isolate, OS99-G-7a (G7a), from a Japanese commercial field contained two paralogs of AVR-Pita1, designated as AVR-Pita1JA and AVR-Pita1JB. Analysis of virulent, independent mutants derived from G7a, a single avirulent progenitor strain, indicated that AVR-Pita1JA was functional but AVR-Pita1JB was nonfunctional. The most frequent mutation was loss of AVR-Pita1JA. Analyses of field isolates collected from diverse areas in Japan revealed that most of the AVR-Pita1 genes carried by Japanese isolates were identical to AVR-Pita1JA or AVR-Pita1JB. The relationship between these major paralogs in Japanese isolates and the virulence of the strains carrying them indicate that AVR-Pita1JA is functional but AVR-Pita1JB is not, as is the case in G7a. Isolates that show virulence toward rice cultivars containing the Pita gene are presumed to have evolved virulence from avirulent origins via loss of AVR-Pita1JA, except for one case in which virulence resulted from a base substitution. In this study, we discuss the properties and specificities of Japanese rice blasts that relate to virulence against Pita-containing rice. Furthermore, we present a method to amplify AVR-Pita1JA and AVR-Pita1JB separately and, specifically, to monitor functional AVR-Pita1 in Japan.

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Identification of an Avirulence Gene in the Fungus Magnaporthe grisea Corresponding to a Resistance Gene at the Pik Locus

Phytopathology ◽

10.1094/phyto-95-0768 ◽

2005 ◽

Vol 95 (7) ◽

pp. 768-772 ◽

Cited By ~ 14

Author(s):

N. Yasuda ◽

M. T. Noguchi ◽

Y. Fujita

Keyword(s):

Resistance Gene ◽

Genetic Basis ◽

Magnaporthe Grisea ◽

Fragment Length Polymorphism ◽

Random Amplified Polymorphic Dna ◽

Genetic Maps ◽

Avirulence Gene ◽

Chinese Isolate ◽

Rice Cultivars ◽

Almost All

A rice isolate of Magnaporthe grisea collected from China was avirulent on rice cvs. Hattan 3 and 13 other Japanese rice cultivars. The rice cv. Hattan 3 is susceptible to almost all Japanese blast fungus isolates from rice. The genetic basis of avirulence in the Chinese isolate on Japanese rice cultivars was studied using a cross between the Chinese isolate and a laboratory isolate. The segregation of avirulence or virulence was studied in 185 progeny from the cross, and monogenic control was demonstrated for avirulence to the 14 rice cultivars. The resistance gene that corresponds to the avirulence gene (Avr-Hattan 3) is thought to be located at the Pik locus. Resistance and susceptibility in response to the Chinese isolate in F3 lines of a cross of resistant and susceptible rice cultivars were very similar to the Pik tester isolate, Ken54-20. Random amplified polymorphic DNA markers and restriction fragment length polymorphism markers from genetic maps of the fungus were used to construct a partial genetic map of Avr-Hattan 3. We obtained several flanking markers and one co-segregated marker of Avr-Hattan 3 in the 144 mapping population.

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A Telomeric Avirulence Gene Determines Efficacy for the Rice Blast Resistance Gene Pi-ta

The Plant Cell ◽

10.2307/3871102 ◽

2000 ◽

Vol 12 (11) ◽

pp. 2019 ◽

Cited By ~ 8

Author(s):

Marc J. Orbach ◽

Leonard Farrall ◽

James A. Sweigard ◽

Forrest G. Chumley ◽

Barbara Valent

Keyword(s):

Resistance Gene ◽

Rice Blast ◽

Blast Resistance ◽

Avirulence Gene ◽

Rice Blast Resistance ◽

Blast Resistance Gene

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Dynamic Insertion of Pot3 in AvrPib Prevailing in a Field Rice Blast Population in the Philippines Led to the High Virulence Frequency Against the Resistance Gene Pib in Rice

Phytopathology ◽

10.1094/phyto-06-18-0198-r ◽

2019 ◽

Vol 109 (5) ◽

pp. 870-877 ◽

Cited By ~ 1

Author(s):

Toluwase Olukayode ◽

Berlaine Quime ◽

Yin-Chi Shen ◽

Mary Jeannie Yanoria ◽

Suobing Zhang ◽

...

Keyword(s):

Resistance Gene ◽

Rice Blast ◽

Indica Rice ◽

The Philippines ◽

Avirulence Gene ◽

Rice Varieties ◽

Breeding Programs ◽

Genome Wide ◽

A Genome ◽

Polymerase Chain

The Magnaporthe oryzae avirulence gene AvrPib is required for the resistance mediated by its cognate resistance gene Pib, which has been intensively used in indica rice breeding programs in many Asian countries. However, the sequence diversity of AvrPib among geographically distinct M. oryzae populations was recently shown to be increasing. Here, we selected a field population consisting of 248 rice blast isolates collected from a disease hotspot in Philippine for the analysis of AvrPib haplotypes and their pathogenicity against Pib. We found that all of the isolates were virulent to Pib and each of them contained an insertion of Pot3 transposon in AvrPib. Moreover, Pot3 insertion was detected in different genomic positions, resulting in three different AvrPib haplotypes, designated avrPib-H1 to H3. We further conducted a genome-wide Pot2 fingerprinting analysis by repetitive element palindromic polymerase chain reaction (PCR) and identified seven different lineages out of 47 representative isolates. The isolates belonging to the same lineage often had the same AvrPib haplotype. In contrast, the isolates having the same AvrPib haplotypes did not always belong to the same lineages. Both mating types MAT1-1 and MAT1-2 were identified in the population in Bohol and the latter appeared dominant. On the host side, we found that 32 of 52 released rice varieties in the Philippines contained Pib diagnosed by PCR gene-specific primers and DNA sequencing of gene amplicons, suggesting that it was widely incorporated in different rice varieties. Our study highlights the genetic dynamics of rice blast population at both the AvrPib locus and the genome-wide levels, providing insight into the mechanisms of the mutations in AvrPib leading to the breakdown of Pib-mediated resistance in rice.

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Function and evolution of Magnaporthe oryzae avirulence gene AvrPib responding to the rice blast resistance gene Pib

Scientific Reports ◽

10.1038/srep11642 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 51

Author(s):

Shulin Zhang ◽

Ling Wang ◽

Weihuai Wu ◽

Liyun He ◽

Xianfeng Yang ◽

...

Keyword(s):

Resistance Gene ◽

Magnaporthe Oryzae ◽

Rice Blast ◽

Blast Resistance ◽

Avirulence Gene ◽

Rice Blast Resistance ◽

Blast Resistance Gene

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Understanding the Co-evolution of the Rice Blast Resistance Gene PI-TA and Magnaporthe oryzae Avirulence Gene AVR-PITA

Advances in Genetics, Genomics and Control of Rice Blast Disease ◽

10.1007/978-1-4020-9500-9_14 ◽

2009 ◽

pp. 137-147 ◽

Cited By ~ 4

Author(s):

Yulin Jia ◽

Xueyan Wang ◽

Stefano Costanzo ◽

Seonghee Lee

Keyword(s):

Resistance Gene ◽

Magnaporthe Oryzae ◽

Rice Blast ◽

Blast Resistance ◽

Avirulence Gene ◽

Rice Blast Resistance ◽

Blast Resistance Gene

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A Telomeric Avirulence Gene Determines Efficacy for the Rice Blast Resistance Gene Pi-ta

The Plant Cell ◽

10.1105/tpc.12.11.2019 ◽

2000 ◽

Vol 12 (11) ◽

pp. 2019-2032 ◽

Cited By ~ 312

Author(s):

Marc J. Orbach ◽

Leonard Farrall ◽

James A. Sweigard ◽

Forrest G. Chumley ◽

Barbara Valent

Keyword(s):

Resistance Gene ◽

Rice Blast ◽

Blast Resistance ◽

Avirulence Gene ◽

Rice Blast Resistance ◽

Blast Resistance Gene

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Evolution of an Avirulence Gene, AVR1-CO39, Concomitant with the Evolution and Differentiation of Magnaporthe oryzae

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-18-1148 ◽

2005 ◽

Vol 18 (11) ◽

pp. 1148-1160 ◽

Cited By ~ 38

Author(s):

Yukio Tosa ◽

Jun Osue ◽

Yukiko Eto ◽

Hong-Sik Oh ◽

Hitoshi Nakayashiki ◽

...

Keyword(s):

Resistance Gene ◽

Ribosomal Dna ◽

Magnaporthe Oryzae ◽

Dna Sequences ◽

Early Stage ◽

Pyricularia Oryzae ◽

Avirulence Gene ◽

Rice Cultivars ◽

Blast Fungus ◽

Specific Subgroup

The significance of AVR1-CO39, an avirulence gene of the blast fungus corresponding to Pi-CO39(t) in rice cultivars, during the evolution and differentiation of the blast fungus was evaluated by studying its function and distribution in Pyricularia spp. When the presence or absence of AVR1-CO39 was plotted on a dendrogram constructed from ribosomal DNA sequences, a perfect parallelism was observed between its distribution and the phylogeny of Pyricularia isolates. AVR1-CO39 homologs were exclusively present in one species, Pyricularia oryzae, suggesting that AVR1-CO39 appeared during the early stage of evolution of P. oryzae. Transformation assays showed that all the cloned homologs tested are functional as an avirulence gene, indicating that selection has maintained their function. Nevertheless, Oryza isolates (isolates virulent on Oryza spp.) in P. oryzae exceptionally noncarriers of AVR1-CO39. All Oryza isolates suffered from one of the two types of known rearrangements at the Avr1-CO39 locus (i.e., G type and J type). These types were congruous to the two major lineages of Oryza isolates from Japan determined by MGR586 and MAGGY. These results indicate that AVR1-CO39 was lost during the early stage of evolution of the Oryza-specific subgroup of P. oryzae. Interestingly, its corresponding resistance gene, Pi-CO39(t), is not widely distributed in Oryza spp.

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