Complete Genomic Sequence Analysis of a Sugarcane Streak Mosaic Virus Isolate from Yunnan Province of China

Development and application of sugarcane streak mosaic virus vectors

Sugarcane streak mosaic virus (SCSMV) is one of the major pathogens of sugarcane in the world. Molecular studies and disease management of SCSMV are hindered by the lack of efficient infectious clones. In this study, we successfully constructed Agrobacterium infiltration based infectious clone of SCSMV with different variants. Infectious clones of wild type SCSMV could efficiently infect Nicotiana benthamiana and sugarcane plants resulting in streak and mosaic symptoms on systemic leaves which were further confirmed with RT-PCR and serological assays. SCSMV variants of less adenylation displayed attenuated pathogenicity on N.benthamiana. SCSMV-based recombinant heterologous EGFP protein vector was also developed. The EGFP-tagged recombinant SCSMV could highly expressed in vegetative organs including roots. These infectious clones of SCSMV could be further developed for platform tools for both biotechnological studies and management of SCSMV disease.

Historical Review of Sugarcane Streak Mosaic Virus that Has Recently Emerged in Africa

Sugarcane streak mosaic virus (SCSMV), now assigned to the genus Poacevirus of the family Potyviridae, was reported for the first time in 1932 in Louisiana and was believed to be strain F of sugarcane mosaic virus (SCMV) for more than six decades. SCMV-F was renamed SCSMV in 1998 after partial sequencing of its genome and phylogenetic investigations. Following the development of specific molecular diagnostic methods in the 2000s, SCSMV was recurrently found in sugarcane exhibiting streak mosaic symptoms in numerous Asian countries but not in the Western hemisphere or in Africa. In this review, we give an overview of the current knowledge on this disease and the progression in research on SCSMV. This includes symptoms, geographical distribution and incidence, diagnosis and genetic diversity of the virus, epidemiology, and control. Finally, we highlight future challenges, as sugarcane streak mosaic has recently been found in Africa, where this disease represents a new threat to sugarcane production.