Molecular Plant-Microbe Interactions (2005) 18, 1148-1160

Yukio Tosa, Jun Osue, Yukiko Eto, Hong-Sik Oh, Hitoshi Nakayashiki, Shigeyuki Mayama and Sally A. Leong (2005)
Evolution of an avirulence gene, AVR1-CO39, concomitant with the evolution and differentiation of Magnaporthe oryzae
Molecular Plant-Microbe Interactions 18 (11), 1148-1160
Abstract: 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 were 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.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Yukio Tosa, Hitoshi Nakayashiki

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pyricularia oryzae	Rice (Oryza)