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. 2018 May;19(5):1252-1256.
doi: 10.1111/mpp.12609. Epub 2017 Dec 10.

Rmg8 and Rmg7, wheat genes for resistance to the wheat blast fungus, recognize the same avirulence gene AVR-Rmg8

Vu Lan Anh  1 , Yoshihiro Inoue  1 , Soichiro Asuke  1 , Trinh Thi Phuong Vy  1 , Nguyen Tuan Anh  1 , Shizhen Wang  1 , Izumi Chuma  1 , Yukio Tosa  1
Affiliations

Rmg8 and Rmg7, wheat genes for resistance to the wheat blast fungus, recognize the same avirulence gene AVR-Rmg8

Vu Lan Anh et al. Mol Plant Pathol. 2018 May.

Abstract

Rmg8 and Rmg7 are genes for resistance to the wheat blast fungus (Pyricularia oryzae), located on chromosome 2B in hexaploid wheat and chromosome 2A in tetraploid wheat, respectively. AVR-Rmg8, an avirulence gene corresponding to Rmg8, was isolated from a wheat blast isolate through a map-based strategy. The cloned fragment encoded a small protein containing a putative signal peptide. AVR-Rmg8 was recognized not only by Rmg8, but also by Rmg7, suggesting that these two resistance genes are equivalent to a single gene from the viewpoint of resistance breeding.

Keywords: Magnaporthe oryzae; Pyricularia oryzae; avirulence gene; gene-for-genes; wheat blast.

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Figures

Figure 1
Figure 1
Pedigree of Pyricularia oryzae strains used in this study.
Figure 2
Figure 2
Genetic map of the AVR‐Rmg8 region constructed using 67 BC1F1 cultures derived from Br48 × 200R29. The original positions of markers reported by Zheng et al. (2008) are shown on the right. cM, centimorgans.
Figure 3
Figure 3
Cloning of AVR‐Rmg8. (a) Fine genetic map of the AVR‐Rmg8 region constructed using 58 recombinants selected from 449 BC1F1 cultures derived from Br48 × 200R29 with two flanking markers, MAT and MGM301. Shown in square brackets are the numbers of recombinants between markers. (b) Physical map of the 45‐kb region delimited by the fine mapping in (a). Black arrows indicate the five candidate genes detected in this region. Shown in parentheses are the number of transformants avirulent on S‐615/number of transformants tested. (c) Detailed analysis of the 2.3‐kb fragment selected in (b). White arrows indicate the primers used for the amplification of fragments F2.2, F1.7 and F1.1. Shown in parentheses are the number of transformants avirulent on S‐615/number of transformants tested. (d) Nucleotide and amino acid sequences of gene 4315.4 (AVR‐Rmg8) conferring avirulence on S‐615. The predicted signal peptide is shadowed.
Figure 4
Figure 4
Symptoms on primary leaves of S‐615 (rmg7/Rmg8), St24 (Rmg7/rmg8), Sch (rmg7/rmg8) and Hope (rmg7/rmg8) inoculated with Br48 (Triticum isolate), 200R54 (F1 culture derived from Br48 × MZ5‐1‐6), and transformants of 200R54 carrying an empty vector (200R54 + Vector), F2.2 (200R54 + F2.2), F1.7 (200R54 + F1.7) and F1.1 (200R54 + F1.1), 6 days after inoculation. One representative transformant was arbitrarily chosen from each of the eight to nine transformants with F2.2, F1.7 and F1.1 (Fig. 3c).
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References

    1. Anh, V.L. , Anh, N.T. , Tagle, A.G. , Vy, T.T.P. , Inoue, Y. , Takumi, S. , Chuma, I. and Tosa, Y. (2015) Rmg8, a new gene for resistance to Triticum isolates of Pyricularia oryzae in hexaploid wheat. Phytopathology, 105, 1568–1572. - PubMed
    1. Ashfield, T. , Ong, L.E. , Nobuta, K. , Schneider, C.M. and Innes, R.W. (2004) Convergent evolution of disease resistance gene specificity in two flowering plant families. Plant Cell, 16, 309–318. - PMC - PubMed
    1. Bhattacharya, R. and Mondal, H. (2017) Fungus sees wheat crops in Bengal go up in flames as govt controls its spread Available at: http://www.hindustantimes.com/india-news/fungus-sees-wheat-crops-in-beng.... Accessed on Sept. 8, 2017.
    1. Callaway, E. (2016) Devastating wheat fungus appears in Asia for first time. Nature, 532, 421–422. - PubMed
    1. Cruz, C.D. , Bockus, W.W. , Stack, J.P. , Tang, X. , Valent, B. , Pedley, K.F. and Peterson, G.L. (2012) Preliminary assessment of resistance among U.S. wheat cultivars to the Triticum pathotype of Magnaporthe oryzae . Plant Dis. 96, 1501–1505. - PubMed

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