Soybean mosaic virus: a successful potyvirus with a wide distribution but restricted natural host range

Abstract

The interactions of SMV with soybean genotypes containing different dominant R genes and an understanding of the functional role(s) of SMV-encoded proteins in virulence, transmission and pathogenicity have been investigated intensively. The SMV-soybean pathosystem has become an excellent model for the examination of the genetics and genomics of a uniquely complex gene-for-gene resistance model in a crop of worldwide importance.

Soybean RNA interference lines silenced for eIF4E show broad potyvirus resistance

“…Considerable efforts have been made to exploit genes conferring resistance to diverse SMV strains in soybean. To date, four independent single‐dominant resistance loci ( Rsv1 , Rsv3 , Rsv4, and Rsv5 ) and a series of Rsc loci conferring resistance to the U.S. and Chinese SMV strains have been fine‐mapped to soybean chromosomes 2, 6, 13, and 14 (MLG‐D1b, C2, F, and B2) (Hajimorad et al ., ). Although Rsv and Rsc loci are located in close proximity to each other, the allelic relationship between them remains unclear, and none of these genes have been cloned thus far, therefore it is impossible to simply transform the resistance genes for generating transgenic SMV resistance (Liu et al ., ; Hajimorad et al ., ).…”

“…To date, four independent single‐dominant resistance loci ( Rsv1 , Rsv3 , Rsv4, and Rsv5 ) and a series of Rsc loci conferring resistance to the U.S. and Chinese SMV strains have been fine‐mapped to soybean chromosomes 2, 6, 13, and 14 (MLG‐D1b, C2, F, and B2) (Hajimorad et al ., ). Although Rsv and Rsc loci are located in close proximity to each other, the allelic relationship between them remains unclear, and none of these genes have been cloned thus far, therefore it is impossible to simply transform the resistance genes for generating transgenic SMV resistance (Liu et al ., ; Hajimorad et al ., ). In addition, the resistance spectrum of the Rsv and Rsc loci is limited or late‐susceptible, making it difficult to cultivate soybean varieties with multistrain SMV resistance through traditional breeding programmes, which is a labour‐intensive and time‐consuming process, and is always accompanied by the generation of undesirable traits (Gao et al ., ).…”

“…However, it is still not known if eIF4E-VPg interaction is the unique determinant of potyviral infectivity in a wide range of plant-potyvirus pairs (Mazier et al, 2011). As shown in Chinese SMV strains have been fine-mapped to soybean chromosomes 2, 6, 13, and 14 (MLG-D1b, C2, F, and B2) (Hajimorad et al, 2018). Although Rsv and Rsc loci are located in close proximity to each other, the allelic relationship between them remains unclear, and none of these genes have been cloned thus far, therefore it is impossible to simply transform the resistance genes for generating transgenic SMV resistance (Liu et al, 2016;Hajimorad et al, 2018).…”

“…and viruses, which are responsible for significant economic losses annually (Liu et al, 2016;Whitham et al, 2016). Among these, soybean mosaic virus (SMV) is the most widespread and devastating viral pathogen in soybean-growing areas, resulting in serious yield reductions and seed quality deterioration (Hill and Whitham, 2014;Hajimorad et al, 2018). Yield losses are usually reported to be approximately 8-35% (Hill and Whitham, 2014); however, losses of more than 50% and even total crop failure have been documented during severe outbreaks (Liao et al, 2002).…”

“…Soybean mosaic virus is a member of the largest and most successful genus of plant pathogenic viruses, Potyvirus, within the family Potyviridae (Adams et al, 2005;Luan et al, 2016). Similar to other potyviruses, the genome of SMV is a monopartite, single-stranded, positive-sense RNA molecule of approximately 10 kb, harboring a viral genome-linked protein (VPg) covalently attached to the 5′ terminus and a poly(A) tail at the 3′ end (Gagarinova et al, 2008;Hajimorad et al, 2018). The viral genome contains two open reading frames (ORF) encoding 11 mature multifunctional proteins, namely protein 1 (P1), helper component-proteinase (HC-Pro), protein 3 (P3), pretty interesting Potyviridae ORF (P3N-PIPO), six kilodalton 1 (6K1), cylindrical inclusion protein (CI), six kilodalton 2 (6K2), VPg, nuclear inclusion a-proteinase (NIa-Pro), nuclear inclusion b (NIb), and coat protein (CP) (Chung et al, 2008;Gagarinova et al, 2008).…”