Grapevine is a widely grown fruit crop that is seriously affected by different viruses, reducing grape yield and quality, as well as threatening profitability. Vineyard disease management requires ...accurate identification of viral infections. This study aimed to survey the presence of ten grapevine viruses in four geographic sites in the Mendoza province of Argentina. Two hundred twenty-three composite cane samples from 1060 plants of six cultivars were collected from 26 blocks distributed across 11 vineyards. The cane samples were screened by RT-PCR for the following viruses: grapevine leafroll-associated viruses 1-4 (GLRaV 1, 2, 3, and 4), grapevine fanleaf virus (GFLV), grapevine fleck virus (GFkV), grapevine virus A (GVA) and B (GVB), grapevine rupestris stem pitting associated virus (GRSPaV), and arabis mosaic virus (ArMV). The results showed an uneven occurrence of viruses through the sampled regions, with GRSPaV being prevalent (71.1%), followed by GFLV (28.9%), GFkV (20.6%), and GLRaV-2 (14.7%). GVB was not detected. This study revealed a moderate prevalence of viruses associated with economically impactful diseases in the vineyards surveyed.
ABSTRACT
The plant vascular system has remained an underexplored niche despite its potential for hosting beneficial microbes. The aim of this work was to determine the origin of the microbial ...endophytes inhabiting grapevine. We focused on a single commercial vineyard in California over a two-year period and used an amplicon metagenomics approach to profile the bacterial (16S–V4) and fungal (ITS) communities of the microbiome across a continuum of six grapevine compartments: bulk soil, rhizosphere, root, cordon, cane and sap. Our data supported that roots are a bottleneck to microbial richness and that they are mostly colonized with soilborne microbes, including plant growth-promoting bacteria recruited by the host, but also saprophytic and pathogenic fungal invaders. A core group of taxa was identified throughout the vine; however, there was clear partitioning of the microbiome with niche adaptation of distinct taxonomic groups. Above- and belowground plant tissues displayed distinct microbial fingerprints and were intermixed in a limited capacity mostly by way of the plant sap. We discuss how cultural practices and human contact may shape the endosphere microbiome and identify potential channels for transmission of its residents.
This study investigates the origin and assembly of the microbial endophytes inhabiting grapevine, and highlights bacteria and fungi that may play a role in the host environmental fitness.
Summary During May and June of 2021, a total of 123 grapevine leaf samples were collected and analyzed for infection by grapevine fanleaf virus (GFLV) and three viruses from the grapevine ...leafroll-associated virus complex -1, -2 and -3 (GRLaV-1, GRLaV-2 and GRLaV-3, respectively). The samples were collected from commercial vineyards, small backyard vineyards and grapevine nurseries located across the entire Vojvodina Province (Bačka, Banat and Srem). OEPP/EPPO sampling protocols were followed during the sampling of leaf tissues showing possible virus infection symptoms. Among the 123 samples, 47 were collected from Bačka region (Bačko Gradište − 11, Bečej − 10, Temerin − 15, Vrbas − 1, Hajdukovo − 10), 50 from Banat region (Srpska Crnja − 10, Vojvode Stepe − 10, Čoka − 10, Uljma −20) and 26 from Srem region (Šid − 6, Banoštor − 10, Sremski Karlovci − 10) and serological ELISA tests were performed for virus detection. GFLV was detected in five samples (4.06%), GLRaV-1 was detected in six samples (4.87%), while GLRaV-2 was not detected in any of the analyzed grapevine samples. GLRaV-3 was present in five samples (4.06%). When infection rates were examined in relation to cultivars, GFLV was detected in Cardinal, Zalagyöngye, Black Muscat, Italian Riesling and Dornfelder. GRLaV-1 was detected in cultivars Cardinal, Black Muscat, Italian Riesling and Merlot, and GRLaV-3 in cultivars Othello and Italian Riesling. Based on these results, it can be concluded that GFLV and GRLaV-1 and GRLaV-3 are present in vineyards across Vojvodina Province and affect different grapevine cultivars. To effectively control virus infections and their spreading, continuous monitoring of these viruses and their vectors is required along with the planting of healthy propagation material.
An interactive relationship between vitiviruses and grapevine leafroll viruses was characterized in grapevine.
Grapevine viruses A
and
B
(GVA and GVB) were found more frequently in the presence of ...co-infecting
Grapevine leafroll associated viruses
(GLRaV-1, −2 or −3) than in their absence. The titers of the vitiviruses in co-infection with leafroll viruses were found to be higher than were their titers in the absence of leafroll virus infection. The occurrence of vitivirus-associated stem-pitting symptoms was correlated with leafroll virus co-infection. Specific pairing associations on the species level were found between different viti- and leafroll virus species: GVB was associated preferentially with GLRaV-2; GVA was associated preferentially with GLRaV-1 and GLRaV-3. In contrast to the increase in vitivirus titer seen with leafroll virus co-infection, the incidence and titer of grapevine leafroll virus appeared to be unaltered by vitivirus co-infection. The potential for a synergistic enhancement of grapevine disease in co-infected vines is discussed.
The combined availability of whole genome sequences and genome editing tools is set to revolutionize the field of fruit biotechnology by enabling the introduction of targeted genetic changes with ...unprecedented control and accuracy, both to explore emergent phenotypes and to introduce new functionalities. Although plasmid-mediated delivery of genome editing components to plant cells is very efficient, it also presents some drawbacks, such as possible random integration of plasmid sequences in the host genome. Additionally, it may well be intercepted by current process-based GMO regulations, complicating the path to commercialization of improved varieties. Here, we explore direct delivery of purified CRISPR/Cas9 ribonucleoproteins (RNPs) to the protoplast of grape cultivar
and apple cultivar such as
fruit crop plants for efficient targeted mutagenesis. We targeted
, a susceptible gene in order to increase resistance to powdery mildew in grape cultivar and
, and
in the apple to increase resistance to fire blight disease. Furthermore, efficient protoplast transformation, the molar ratio of Cas9 and sgRNAs were optimized for each grape and apple cultivar. The targeted mutagenesis insertion and deletion rate was analyzed using targeted deep sequencing. Our results demonstrate that direct delivery of CRISPR/Cas9 RNPs to the protoplast system enables targeted gene editing and paves the way to the generation of DNA-free genome edited grapevine and apple plants.
Xylella fastidiosa (Xf) is a plant pathogen which attacks vines, citrus fruits, olive, almond and several many other species, causing considerable economic losses. In the last few years Xf has become ...a global threat after being a local problem for decades: while it was once known only in circumscribed regions of the Americas, in 2013 it began to devastate olive groves in Southern Italy, and its presence has also been reported in France, Spain, and Portugal. Even though Xf has been under study since the late 1980s, the rapid worldwide spread raises the question of whether research infrastructure is adequately prepared to address new challenges, such as the need for novel methods to control and prevent Xf infection, gaining a deeper understanding of its biology and life cycle to identify vulnerable intervention points, coordinating international responses to combat its spread, and mitigating impacts on crops and the agricultural environment. Using a bibliometric approach, this study tried to answer this question by tracing an overview of the evolution of Xf literature from 1989 to present. The analysis was conducted on the Scopus database focusing separately on three periods (1989–1999; 2000–2010; 2011–2021). After a pioneering phase in 1989–1999, the intermediate period resulted the one with the highest scientific production, in which most currently ongoing research lines were started. The last period showed a revitalization of research after some years of decline, mostly due to the recent outbreak on olive in Europe, but it was characterized by a slower increment of topics with a growth of interconnection level among themes, indicating an ongoing process of consolidation of the established research lines. The authorship and thematic characterization demonstrated that Xf research was shaped by a "geographical factor", which has represented a crucial element over time and continues to have an impact on how collaborations and topics are organized.
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•Xylella fastidiosa (Xf) is the pathogenic cause of severe diseases in many tree crops.•Once known only in the Americas, it has recently spread to Europe.•It has been investigated how research is responding to the pathogen's global spread.•To this end, a bibliometric analysis embracing 33 years of Xf literature was performed.
Grapevine leafroll disease (GLD) is one of the most economically damaging virus diseases in grapevine, with grapevine leafroll-associated virus 1 (GLRaV-1) and grapevine leafroll-associated virus 3 ...(GLRaV-3) as the main contributors. This study complements a previously published transcriptomic analysis and compared the impact of two different forms of GLD to a symptomless control treatment: a mildly symptomatic form infected with GLRaV-1 and a severe form with exceptionally early leafroll symptoms (up to six weeks before veraison) infected with GLRaV-1 and GLRaV-3. Vine physiology and fruit composition in 17-year-old Pinot noir vines were measured and a gradient of vigor, yield, and berry quality (sugar content and berry weight) was observed between treatments. Virome composition, confirmed by individual RT-PCR, was compared with biological indexing. Three divergent viromes were recovered, containing between four to seven viruses and two viroids. They included the first detection of grapevine asteroid mosaic-associated virus in Switzerland. This virus did not cause obvious symptoms on the indicators used in biological indexing. Moreover, the presence of grapevine virus B (GVB) did not cause the expected corky bark symptoms on the indicators, thus underlining the important limitations of the biological indexing. Transmission of GLRaV-3 alone or in combination with GVB by Planococcus comstocki mealybug did not reproduce the strong symptoms observed on the donor plant infected with a severe form of GLD. This result raises questions about the contribution of each virus to the symptomatology of the plant.
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