Molecular characterization of a Strawberry mild yellow edge virus isolate from Canada

摘要

Over the past several years, strawberry production in Canada and the United States has been severely affected by strawberry acute decline symptoms. The decline disease is apparently caused by synergistic infections of several viruses, including Strawberry mild yellow edge virus (SMYEV) and Strawberry mottle virus (SMoV). To better understand the causal viral pathogens, we cloned and sequenced the entire genome of a SMYEV isolate, AB5-2, from a strawberry field in Prince Edward Island. The viral genome of AB5-2 consists of 5969 nucleotides excluding the 3' terminal poly(A) tail. Searches of the NCBI database identified two SMYEV isolates (MY-18 from the USA and D74 from Germany) whose complete genome sequences were documented and 28 SMYEV isolates with determined coat protein (CP) sequences. At the genome level, the Canadian SMYEV isolate shares 86% and 90% nucleotide sequence identities to MY-18 and D74, respectively. Phylogenetic analysis of all CP sequences available clustered 28 SMYEV isolates into five phylogroups, including AB5-2 alone as a new group, suggesting this Canadian isolate is distinct from SMYEV isolates of other origins. This report represents the first molecular characterization of a SMYEV isolate from Canada. ResumeAu cours des dernieres annees, la production de fraises au Canada et aux Etats-Unis a ete gravement touchee par des symptomes de deperissement aigu. La maladie du deperissement est apparemment causee par l'infection synergique de plusieurs virus, y compris du virus du jaunissement du bord des feuilles du fraisier (SMYEV) et du virus de la marbrure du fraisier (SMoV). Afin de mieux comprendre les virus pathogenes, nous avons clone et sequence tout le genome d'un isolat de SMYEV, AB5-2, provenant d'une fraisiere de l'ile-du-Prince-Edouard. Le genome viral d'AB5-2 comporte 5969 nucleotides, a l'exception de la queue poly(A) en 3'. Des recherches effectuees dans la base de donnees du National Center for Biotechnology Information (NCBI) ont permis de trouver 2 isolats de SMYEV (MY-18, des Etats-Unis, et D74, d'Allemagne) dont les genomes entiers etaient documentes, et 28 isolats qui possedaient des sequences determinees de proteine capsidiaire (CP). l'echelle du genome, l'isolat canadien de SMYEV partage 86% et 90% de l'identite des sequences des nucleotides avec MY-18 et D74, respectivement. L'analyse phylogenetique de toutes les sequences de CP disponibles a rassemble les 28 isolats de SMYEV en 5 phylogroupes, y compris AB5-2 comme nouveau groupe unique, ce qui suggere que cet isolat canadien est different des isolats de SMYEV provenant d'ailleurs. Ce rapport constitue la premiere caracterisation moleculaire d'un isolat canadien de SMYEV.