Archivio Journal of Plant Pathology

Abstract:

The complete genome sequence of leek yellow stripe virus (LYSV) isolate AC-50 from garlic in India was determined and the predicted amino acid (aa) sequence was analyzed. The LYSV RNA genome is 10,131 nucleotides (nt) long excluding the poly(A) tail (KP168261) and has a large open reading frame (ORF) encoding a putative polyprotein of 3152 aa with conserved motifs typical of members of the genus Potyvirus in the family Potyviridae. The pretty interesting Potyviridae ORF (PIPO) coding region was identified in the P3 coding region. LYSV isolate AC-50 shares maximum nt and aa sequence identity of 79.9% and 87.2% with a LYSV isolate from Australia (HQ258895) at the full genome and polyprotein level, respectively, and clusters with clade II isolates from China, Mexico, Australia, Brazil and Spain. The P1 coding region of isolate AC-50 was highly variable with an identity range of 48.9-70.9% with other LYSV isolates and a deletion of 204 nt compared to Japanese and Australian isolates. The ratio of nonsynonymous (dN) and synonymous (dS) polymorphic sites suggested that purifying selection dominates in the evolution of LYSV and the mean dN/dS ratio was highest for P1, confirming that this coding region is under less evolutionary constraints.