Identification of a pathogenicity determinant of Plum pox virus in the sequence encoding the C-terminal region of protein P3+6K1

Abstract

A full-length genomic cDNA clone of a plum pox potyvirus (PPV) isolate belonging to the M strain (PPV-PS) has been cloned downstream from a bacteriophage T7 polymerase promoter and sequenced. Transcripts from the resulting plasmid, pGPPVPS, were infectious and, in herbaceous hosts, produced symptoms that differed from those of virus progeny of pGPPV, a full-length genomic cDNA clone of the D strain PPV-R. Viable PPV-R/-PS chimeric viruses were constructed by recombination of the cDNA clones in vitro. Analysis of plants infected with the different chimeras indicated that sequences encoding the most variable regions of the potyvirus genome, the P1 and capsid protein coding sequences, were not responsible for symptom differences between the two PPV isolates in herbaceous hosts. On the contrary, complex symptomatology determinants seem to be located in the central region of the PPV genome. The results indicate that a genomic fragment that encodes 173 aa from the C-terminal part of the P3M6K 1 coding region is enough to confer, on a PPV-R background, a PS phenotype in Nicotiana clevelandii. This pathogenicity determinant also participates in symptom induction in Pisum sativum, although the region defining the PS phenotype in this host is probably restricted to 74 aa.

Unfolding the secrets of plum pox virus: from epidemiology to genomics

“…As an alternative to commercial devices, various simpler gene delivery systems may be applied (Gray et al, 1994;Sikorskaite et al, 2010) including sport air guns with either inert metals (gold, tungsten) or diatomaceous earth (Celite) used as nucleic acid carriers Nagyová et al, 2011). Infectious clones of several PPV isolates have been constructed (Maiss et al, 1992;Riechmann et al, 1990;Sáenz et al, 2000;Predajňa et al, 2012a) and applied for studies of the infectious cycle and particularly for mapping various phenotypes in the PPV genome. Varrelmann and Maiss (2000) demonstrated two motifs in the CP essential for systemic transport of the infectious clone PPV-NAT (strain PPV-D).…”

Identification of Quantitative Trait Loci Controlling Symptom Development During Viral Infection inArabidopsis thaliana

“…The PPV-R isolate is available as an infectious cDNA clone called pICPPV (Saenz et al 2000). It was initially inoculated by particle-gun bombardment and was then further propagated in N. benthamiana.…”

The Potyviral P3 Protein Targets Eukaryotic Elongation Factor 1A to Promote the Unfolded Protein Response and Viral Pathogenesis

“…The precise biochemical function of SMV P3, and indeed the potyviral P3 protein in general, is largely uncharacterized due to the lack of structural or functional motifs in its sequence. Roles in viral replication, movement, virulence activity, and in one case, avirulence, have been suggested (Rodriguez-Cerezo et al, 1993;Sáenz et al, 2000;Desbiez et al, 2003;Jenner et al, 2003;Choi et al, 2005;Hajimorad et al, 2005Hajimorad et al, , 2006Hjulsager et al, 2006;Eggenberger et al, 2008;). Some potyviral P3 proteins were detected in the nucleoli of early-infected cells, whereas others were detected exclusively in the cylindrical inclusions of infected cells (Rodriguez-Cerezo et al, 1993;Langenberg and Zhang, 1997).…”