Disease resistance. Soil-borne cereal mosaic virus (SBCMV) resistance in bread wheat
SBCMV resistance gene Sbm1
Contributed by Dragan Perovic, Kostya Kanyuka, and Frank Ordon
Soil-borne cereal mosaic virus (SBCMV) that belongs to the genus Furovirus is transmitted by the plasmodiophorid Polymyxa graminis (1). Following transmission by P. graminis, SBCMV is translocated into the upper parts of susceptible plants causing stunting and mosaic symptoms on leaves that are most prominent in early spring. Winter wheat plants infected in autumn are particularly sensitive to frost damage resulting in increased winter killing or reduced vigour during spring. Chemical control except soil fumigation, which is unacceptable for economical and ecological reasons, is ineffective against P. graminis, therefore, the only possibility of controlling this virus on infested fields is the growing of resistant cultivars.
Historically, Soil-borne wheat mosaic virus (SBWMV) was first recognized as a serious winter wheat disease in Indiana and Illinois in 1919 (2) and has subsequently been detected in other winter wheat growing areas around the globe (3-5). In Europe, however, the most common causal agent of mosaic disease of wheat (Triticum aestivum), durum wheat (Triticum durum), rye (Secale cereale) and triticale is SBCMV, a virus species related to SBWMV and until recently considered as a European strain of SBWMV. Complete sequencing of SBWMV and SBCMV genomes revealed that they share only approximately 70% nucleotide identity, and therefore should be classified as separate species (6,7).
SBCMV-resistant wheat cultivars exhibit the so-called ‘translocation resistance’ (8). In such cultivars, virus accumulates to a certain degree in the roots, but its movement from the roots to the stem and leaves is blocked or delayed such that the virus coat protein antigen is undetectable in above ground tissues. A locus for resistance to SBCMV, designated as Sbm1, has been mapped to the long arm of chromosome 5D in the UK wheat cv. Cadenza (9). So far, this is the only one major resistance gene effective against SBCMV.
Perovic et al. (10) determined that microsatellite locus Xgwm469-5D maps 1 cM of Sbm1. They tested a collection of SBCMV resistant and susceptible cultivars. All susceptible genotypes carried a null allele of Xgwm469-5D, whereas resistant genotypes presumably related to either Claire and Tremie or Cadenza revealed a 152-bp or 154-bp allele of Xgwm469-5D, respectively. These authors also developed a modified PCR protocol to improve detection of the resistant allele on Li-Cor, ABI/Beckman or other capillary systems (see Methods), making this dominant marker easier to analyze with high-throughput systems. Also, a set of KASP markers was developed in 2013. the details are available in the methods section.
1. Relation of soil-borne wheat mosaic virus and its fungal vector, Polymyxa graminis. Rao AS, Brakke MK. In: Phytopathology, 1969, 59:581-587
2. Investigation of the rosette disease of wheat and its control. McKinney HH. In: Journal of Agricultural Research, 1923, 23:771-800
3. Assessing resistance of UK winter wheat varieties to Soil-borne wheat mosaic virus and Wheat spindle streak mosaic virus. Budge G, Henry CM. In: HGCA Project Report, 2002, No. 293. Home-Grown Cereals Authority, London, UK
4. Nachweis des Weizenspindelstrichelmosaik-Virus (wheat spindle streak mosaic virus) in der DDR. Proeseler G, Stanarius A. In: Archiv fur Phytopathologie und Pflanzenschutz, 1983, 19:345-349.
5. Studies on soil-borne virus disease of wheat and barley. I. Several properties of viruses. Saito Y, Takanashi K, Iwata Y, Okamoto H. In: Bulletin of the National Institute of Agricultural Sciences (Japan), 1964, Ser C 17:1-19.
6. Soil-borne rye mosaic virus and European wheat mosaic virus: two names for a furovirus with variable genome properties which is widely distributed in several cereal crops in Europe. Koenig R, Huth W. In: Archives of Virology, 2000, 145:689-697. DOI:10.1007/s007050050663.
7. Furovirus. Torrance L, Koenig R. In: Fauquet CM, Mayo MA, Maniloff J, Desselberger U, Ball LA (Eds) Virus Taxonomy, Classification and Nomenclature of Viruses, 2004, Elsevier, Amsterdam, pp. 1027-1032.
8. Multiplication of Soil-borne wheat mosaic virus (SBWMV) in wheat roots infected by a soil carrying SBWMV and Wheat yellow mosaic virus (WYMV). Hariri D, Courtillot M, Zaoui P, Lapierre H. In: Agronomie, 1987, 7:789-796.
9. The Sbm 1 locus conferring resistance to Soil-borne cereal mosaic virus maps to a gene-rich region on 5DL in wheat. Bass C, Hendley R, Adams MJ, Hammond-Kosack KE, Kanyuka K. In: Genome, 2006, 49:1140-1148. DOI:10.1139/G06-064.
10. Mapping and diagnostic marker development for Soil-borne cereal mosaic virus resistance in bread wheat. Perovic D, Förster J, Devaux P, Hariri D, Guilleroux M, Kanyuka K, Lyons R, Weyen J, Feuerhelm D, Kastirr U, Sourdille P, Röder M and Ordon F. In: Molecular breeding, 2009, 23:641–653. DOI:10.1007/s11032-009-9262-2.
11. A microsatellite map of wheat. Röder MS, Korzun V, Wendehake K, Plaschke J, Tixier MH, Leroy P, Ganal MW. In: Genetics, 1998, 149:2007-2023.