Sequencing of two Sunflower chlorotic mottle virus isolates obtained from different natural hosts shed light on its evolutionary history

BEJERMAN, NICOLÁS; GIOLITTI, FABIÁN; DE BREUIL SOLEDAD; LENARDON, SERGIO

VIRUS GENES

SPRINGER

Lugar: Berlin; Año: 2013 vol. 46 p. 105 - 110

0920-8569

Sunflower chlorotic mottle virus (SuCMoV), themost prevalent virus of sunflower in Argentina, was reportednaturally infecting not only sunflower but also weeds. Tounderstand SuCMoV evolution and improve the knowledgeon its variability, the complete genomic sequences of twoSuCMoV isolates collected from Dipsacus fullonum (-dip)and Ibicella lutea (-ibi) were determined from three overlappingcDNA clones and subjected to phylogenetic andrecombination analyses. SuCMoV-dip and -ibi genomeswere 9,953-nucleotides (nt) long; their sequences containedan open reading frame of 9,561 nucleotides, which encoded apolyprotein of 3,187 amino acids flanked by a 50-noncodingregion (NCR) of 135 nt and a 30-NCR of 257 nt. SuCMoVdipand -ibi genome nucleotide sequences were 90.9 identicaland displayed 90 and 94.6 % identity to that ofSuCMoV-C, and 90.8 and 91.4 % identity to that ofSuCMoV-CRS, respectively. P1 of SuCMoV-dip and -ibiwas 3-nt longer than that of SuCMoV-CRS, but 12-nt shorterthan that of SuCMoV-C. Two recombination events weredetected in SuCMoV genome and the analysis of dN/dS ratioamong SuCMoV complete sequences showed that thegenomic regions are under different evolutionary constraints,suggesting that SuCMoV evolution would be conservative.Our findings provide evidence that mutation andrecombination would have played important roles in theevolutionary history of SuCMoV.