Analysis of a new strain of Euphorbia mosaic virus with distinct replication specificity unveils a lineage of begomoviruses with short Rep sequences in the DNA-B intergenic region

摘要: Background: Euphorbia mosaic virus (EuMV) is a member of the SLCV clade, lineage New World begomoviruses that display distinctive features in their replication-associated protein (Rep) and virion-strand replication origin. The first entirely characterized EuMV isolate native from Yucatan Peninsula, Mexico; subsequently, was detected weeds pepper plants another region Mexico, partial DNA-A sequences revealed significant differences putative specificity determinants with respect to EuMV-YP. This study aimed investigate compatibility between two isolates same country. Results: A new obtained collected at Jalisco, Mexico. Full-length clones both genomic components EuMV-Jal were biolistically inoculated into three different species, which developed symptoms indistinguishable those induced by Pseudorecombination experiments EuMV-YP demonstrated these viruses do not form infectious reassortants Nicotiana benthamiana, presumably because Rep-iteron incompatibility. Sequence analysis DNA-B intergenic (IR) led unexpected discovery 35-nt-long sequence identical segment rep gene cognate viral DNA-A. Similar short ranging 35- 51-nt length identified all distinct South America related EuMV. These IR are positioned downstream ~160-nt non-coding domain highly similar CP promoter belonging clade. Conclusions: strains compatible replication, indicating this begomovirus species probably replicating nature. subgroup clade contain component, located CP-promoter-like domain. assemblage DNA-A-related within reminiscent polyomavirus microRNAs could be involved posttranscriptional regulation gene, an intriguing possibility should experimentally explored.