Search Results (4)

Sharka disease, caused by the plum pox virus (PPV), negatively impacts stone fruit production, resulting in economic losses. It has been demonstrated that grafting the almond (Prunus dulcis (Miller) D.A. Webb) variety ‘Garrigues’ into susceptible peach (Prunus persica (L.) Batsch) rootstocks can result in PPV resistance. The molecular circuits related to grafting in Prunus species, however, have not been fully investigated. In this study, susceptible peach rootstocks ‘GF305’ were either heterografted with ‘Garrigues’ almond or homografted with the same cultivar. Peach samples were collected at two stages of scion development, with ungrafted plants utilized as controls. Profiles of transcripts, small RNAs (sRNAs), and DNA methylation were obtained and analyzed on a genome-wide scale. Homografting and heterografting significantly altered the transcriptome and methylome of peach rootstocks, with these modifications being more pronounced during the early stages of scion development. The profiles of sRNAs were significantly more impacted when almonds were used as a scion as opposed to peaches, likely due to the transmission of PPV-unrelated viral sequences. Gene expression differences resulting from DNA methylation alterations are more thoroughly documented at the promoter sequences of genes than within their bodies. This study suggests that the ‘Garrigues’ almond variety triggers a complex defense response in the peach rootstock, potentially involving the interplay of epigenetic modifications and small RNA-mediated priming of antiviral defenses, which ultimately may contribute to PPV resistance. Full article

Viral infections can lead to transplant dysfunction, and their possible role in rejection is described. In total, 218 protocol biopsies performed in 106 children at 6, 12 and 24 months after transplantation were analyzed according to Banff ’15. RT-PCR for cytomegalovirus, Epstein-Barr virus, BK virus and Parvovirus B19 was performed on blood and bioptic samples at the time of transplant and each protocol biopsy. The prevalence of intrarenal viral infection increases between 6 and 12 months after transplantation (24% vs. 44%, p = 0.007). Intrarenal Parvovirus B19 infection is also associated with antibody-mediated rejection (ABMR) (50% ABMR vs. 19% T-cell-mediated rejection, p = 0.04). Moreover, Parvovirus infection is higher at 12 months of follow-up and it decreases at 48 months (40.4% vs. 14%, p = 0.02), while in 24% of grafts, Parvovirus is already detectable at the moment of transplantation. Intrarenal Parvovirus B19 infection seems to be related to ABMR in pediatric kidney recipients. The graft itself may be the way of transmission for Parvovirus, so performance of a PCR test for Parvovirus B19 should be considered to identify high-risk patients. Intrarenal Parvovirus infection presents mainly during the first-year post-transplantation; thus, we recommend an active surveillance of donor-specific antibodies (DSA) in patients with intrarenal Parvovirus B19 infection during this period. Indeed, it should be considered a treatment with intravenous immunoglobulins in patients with intrarenal Parvovirus B19 infection and DSA positivity, even in the absence of ABMR criteria for kidney biopsy. Full article

Virus diseases of strawberry present several complex problems. More than 25 viruses have been described in the genus Fragaria thus far. Here, we describe a novel rhabdovirus, tentatively named strawberry virus 1 (StrV-1), that infects F. ananassa and F. vesca plants. Genomic sequences of three distinct StrV-1 genotypes co-infecting a single F. ananassa host were obtained using combined Illumina and Ion Proton high-throughput sequencing. StrV-1 was transmitted to herbaceous plants via Aphis fabae and A. ruborum, further mechanically transmitted to Nicotiana occidentalis 37B and sub-inoculated to N. benthamiana, N. benthamiana DCL2/4i, N. occidentalis 37B, and Physalis floridana plants. Irregular chlorotic sectors on leaf blades and the multiplication of calyx leaves seem to be the diagnostic symptoms for StrV-1 on indexed F. vesca clones. StrV-1 was detected in asymptomatic grafted plants and in 49 out of 159 field strawberry samples via RT-PCR followed by Sanger sequencing. The bacilliform shape of the virions, which have a cytoplasm-limited distribution, their size, and phylogenetic relationships support the assignment of StrV-1 to a distinct species of the genus Cytorhabdovirus. Acyrthosiphon malvae, A. fabae, and A. ruborum were shown to transmit StrV-1 under experimental conditions. Full article

Chrysanthemum is a vegetative propagated culture in which viral transmission with planting material is important for its production. Chrysanthemum virus B (CVB) belongs to the viruses that strike this plant culture. Chrysanthemum virus B is found everywhere where chrysanthemum is cultivated. Damage to plants by CVB often leads to a complete loss of floral yield. Chrysanthemum (Chrysanthemum morifolium Ramat cv. White Snowdon) was transformed via Agrobacterium-mediated DNA delivery with the aim of improving resistance to CVB infection. Transformation vectors contain the nucleotide sequence of CVB coat proteins (CP) in sense, antisense, and double sense orientation. The transformative vectors also invert repeats of CVB coat protein gene fragments for the induction of RNA-interference. The transgenic chrysanthemum plants were successfully obtained. The integration of the target sequences in plant genomes was confirmed by polymerase chain reaction (PCR) and Southern blot analyses. Chrysanthemum lines were transformed with antisense, sense, and double sense CVB CP sequences, as well as with hairpin RNA-interference constructs that were assayed for resistance to CVB. Infection of transgenic plants by CVB through the grafting of infected scions shows resistance only among plants with carried double sense (16.7%) and hairpin (12.5%) constructs. The plants transformed by sense and double sense sequences were observed and classified as tolerant. Full article