Evolution of wheat blast resistance gene Rmg8accompanied by differentiation of variants recognizing the powdery mildew fungus

Autor: Asuke, Soichiro, Morita, Kohei, Shimizu, Motoki, Abe, Fumitaka, Terauchi, Ryohei, Nago, Chika, Takahashi, Yoshino, Shibata, Mai, Yoshioka, Motohiro, Iwakawa, Mizuki, Kishi-Kaboshi, Mitsuko, Su, Zhuo, Nasuda, Shuhei, Handa, Hirokazu, Fujita, Masaya, Tougou, Makoto, Hatta, Koichi, Mori, Naoki, Matsuoka, Yoshihiro, Kato, Kenji, Tosa, Yukio
Zdroj: Nature Plants; 20240101, Issue: Preprints p1-13, 13p
Abstrakt: Wheat blast, a devastating disease having spread recently from South America to Asia and Africa, is caused by Pyricularia oryzae(synonym of Magnaporthe oryzae) pathotype Triticum, which first emerged in Brazil in 1985. Rmg8and Rmg7, genes for resistance to wheat blast found in common wheat and tetraploid wheat, respectively, recognize the same avirulence gene, AVR-Rmg8. Here we show that an ancestral resistance gene, which had obtained an ability to recognize AVR-Rmg8before the differentiation of Triticumand Aegilops, has expanded its target pathogens. Molecular cloning revealed that Rmg7was an allele of Pm4, a gene for resistance to wheat powdery mildew on 2AL, whereas Rmg8was its homoeologue on 2BL ineffective against wheat powdery mildew. Rmg8variants with the ability to recognize AVR-Rmg8were distributed not only in Triticumspp. but also in Aegilops speltoides, Aegilopsumbellulataand Aegilopscomosa. This result suggests that the origin of resistance gene(s) recognizing AVR-Rmg8dates back to the time before differentiation of A, B, S, U and M genomes, that is, ~5 Myr before the emergence of its current target, the wheat blast fungus. Phylogenetic analyses suggested that, in the evolutionary process thereafter, some of their variants gained the ability to recognize the wheat powdery mildew fungus and evolved into genes controlling dual resistance to wheat powdery mildew and wheat blast.
Databáze: Supplemental Index
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