Characterization of the 3′-terminal nucleotide sequence of two Korean isolates of Daphne virus S support its placement as a distinct species of the genus Carlavirus

Summary.

 This study determined the 3′-terminal nucleotide sequences of two Korean isolates of Daphne virus S (DVS), a tentative member of the genus Carlavirus, causing leaf distortion and chlorotic spot disease symptoms in daphne plants. The 3′-terminal 1,465 nucleotide sequences of the two isolates contained two open reading frames coding for proteins of 36 kDa viral coat protein (CP) and 12 kDa from the 5′–3′ end, which is a typical genome structure of the 3′-terminal region of carlaviruses. Both DVS isolates were 98.1% and 93.6% amino acid identical in the CP and 12 kDa, respectively. The CP gene of DVS shares 25.2–55.2% and 42.9–56.1% similarities with that of 19 other carlaviruses at the amino acid and nucleotide levels, respectively. The 3′-proximal 12 kDa gene of DVS shares 20.2–57.8% amino acid identities with that of 18 other members of the genus. The 3′ noncoding region of DVS consists of 73 nucleotides with long excluding poly A tract, and shares 69.1–77.1% identities to the known carlaviruses. In the phylogenetic analyses of the two proteins, DVS was closely related to Helenium virus S and Chrysanthemum virus B. This is the first sequence information for the DVS, and further confirms the classification of DVS as a distinct member of the genus Carlavirus.