Analysis of the Molecular Variability of Grapevine Leafroll-associated Virus 1 Reveals the Presence of Two Distinct Virus Groups and their Mixed Occurrence in Grapevines

Abstract

Genetic diversity of eight Grapevine leafroll-associated virus 1 (GLRaV-1) isolates recovered from grapevines in three distinct locations in the Czech Republic and Slovakia was characterised by restriction fragment length polymorphism (RFLP) analysis and by sequencing of cloned 540 bp fragment of the heat shock protein 70 (HSP70) gene. Comparison and phylogenetic analysis of obtained and previously available sequence data revealed the existence of two groups of GLRaV-l isolates, tentatively named A and E (genetic divergence between A and E group reached 13.9%). An RT-PCR detection method followed by simple restriction analysis was developed, showing the potential to differentiate GLRaV-1 isolates of these groups. Interestingly, a mixed infection of two GLRaV-1 groups in the same plant was frequently detected together with a high intra-group variability in some isolates.

Populations of Genomic RNAs Devoted to the Replication or Spread of a Bipartite Plant Virus Differ in Genetic Structure

“…For instance, intraisolate diversity of CTV in citrus reached 0.142, with diversity in this case estimated as the genetic distance between two haplotypes (defined by the single-strand conformation polymorphism pattern) (25). For the Hsp70h region of GLRaV-1 in grapevine, diversity values obtained from sequencing data were from 2.0 ϫ 10 Ϫ3 to 3.6 ϫ 10 Ϫ2 , although these figures were obtained from comparison of six or fewer clones (24). The lower level of genetic variation found in ToCV than in CTV and GLRaV-1 might be caused in part by differences in host plants and/or modes of transmission, as suggested for CYSDV (46).…”

“…Intraisolate genetic diversity has been studied for a few members of the Closteroviridae family, namely the closterovirus Citrus tristeza virus (CTV) (2,3,25,47,56), the ampeloviruses Grapevine leafroll-associated virus 1 (GLRaV-1) and GLRaV-3 (24,51), and the criniviruses Cucurbit yellow stunt disease virus (CYSDV) and Lettuce infectious yellows virus (LIYV) (45,46). This paper reports a detailed analysis of within-host viral populations in field isolates of ToCV from southeastern Spain.…”

Analysis of multiple virus-infected grapevine plant reveals persistence but uneven virus distribution

“…In contrast, two different RT-PCRs targeting different genome portions did not detect this virus in all of the samples. The RT-PCR according to Komínek et al (2005) failed to detect GLRaV-1 in all 4 samples from shoot 2 of LN33. On the other hand, the RT-PCR according to Habili et al (2003) consistently detected GLRaV-1 in all 8 samples from LN33.…”

“…For GLRaV-1 detection, ELISA unexpectedly appears to be more effective than RT-PCR probably due to an insufficient specificity of primers, not reflecting the actual genetic variability of the virus (Komínek et al, 2005).…”

General properties of grapevine viruses occurring in Hungary

“…The symptoms have seen mainly at the end of growing season (Meng et al, 2005). A new genus: Ampelovirus, including Grapevine leafroll-associated virus 1 (GLRaV-1), Grapevine leafroll-associated virus 3 (GLRaV-3) with Grapevine leafrollassociated virus 5 (GLRaV-5), was proposed distinct from the genus Closterovirus (Komínek et al, 2005). Tentative species of the genus Ampelovirus are: Grapevine leafroll-associated virus 4 (GLRaV-4), Grapevine leafroll-associated virus 6 (GLRaV-6), Grapevine leafroll-associated virus 8 (GLRaV-8) too.…”