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Ključne besede: diagnostika, virusi, bakterije, fitoplazme, viroidi, varstvo rastlin
Objavljeno v DiRROS: 12.02.2026; Ogledov: 357; Prenosov: 0

Povzetek: Background Aquatic plants play key roles in ecosystems, serving as primary producers and providing habitat for other aquatic life. While many are ecologically important, some invasive species, often introduced through the ornamental plant trade, pose threats to various aquatic ecosystems. Although viral infections have been documented to some extent in aquatic crops, the viral diversity in wild and ornamental aquatic plants remains largely unexplored. Investigating the viral communities of aquatic plants is important, as their direct contact with water allows for the potential long-distance transmission of stable viruses released from infected individuals. Invasive aquatic plants exacerbate this issue by introducing novel microbes, including viruses, to new regions, increasing the potential threat to native plant populations. Results Here, we investigated the viral communities of diverse aquatic plants by mining publicly available transcriptome data of 79 wild aquatic species and sequencing the RNA from 14 plant species (some of them of different ornamental varieties), sourced from hobby aquascaping stores. Plant viruses from various families were detected in taxonomically diverse aquatic plants, ranging from algae to angiosperms. Alongside sequences of known crop pathogens, such as turnip yellows virus, cucumber mosaic virus, and lettuce chlorosis virus, we identified contigs of putative novel viral species belonging to several plant-infecting viral families. Most notably, we discovered sequences of known and novel begomoviruses, which may be causing observed ornamental phenotypes in two different aquatic plants. Further, we identified a novel potyvirus that appears to be globally present in multiple ornamental plants from the genus Sagittaria. We detected it in three plants sourced from online stores in Slovenia, as well as six plants intercepted during the import process into the UK. Conclusions Our findings expand on the so far limited knowledge of aquatic plant viruses, revealing known and putative novel plant viral species across diverse aquatic plant taxa. The detection of crop viruses, including regulated pathogens, in ornamental aquatic plants highlights the risks associated with their unregulated global trade. Further research into viruses of aquatic plants may provide insights into their role in ecosystems as well as their potential impact on agriculture.
Ključne besede: aquatic plants, macrophytes, viromes, high-throughput sequencing, data mining, virology
Objavljeno v DiRROS: 26.11.2025; Ogledov: 753; Prenosov: 157
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Povzetek: Phytoplasmas are non-culturable obligate intracellular bacteria that cause considerable economic losses in agriculture. Genome sequencing provides crucial insights into their biology and vector dependence. However, genome studies on phytoplasmas are often hampered by their low abundance in naturally infected plants. Propagation in test plants is usually necessary but time-consuming and resource-intensive, especially for quarantine phytoplasmas such as the phytoplasma causing Flavescence dorée (FD), a serious threat to European viticulture. To overcome these challenges, we aimed to develop a protocol for efficient enrichment of phytoplasma DNA directly from field-collected samples, enabling genome sequencing using both Illumina and Oxford Nanopore Technologies platforms. We evaluated six sample preparation protocols that included stepwise enrichment steps to improve phytoplasma genome coverage and assembly quality. The most effective approach combined differential centrifugation, CTAB extraction and removal of CpG-methylated host DNA and resulted in a notable increase in the relative abundance of phytoplasma reads compared to other protocols. Rarefaction analysis of the dataset generated using this protocol demonstrated that the entire phytoplasma genome was covered by reads in a dataset comprising 3 billion nucleotides. We also evaluated and compared de novo phytoplasma genome assemblies generated from short Illumina reads and long nanopore sequencing reads. While Illumina sequencing yielded more accurate assemblies with longer total lengths, the assemblies derived from nanopore sequencing data contained longer individual contigs. This advantage was reflected in hybrid assemblies that combined both technologies, yielding longer phytoplasma contigs than assemblies from Illumina datasets and lower mismatch rates compared to assemblies from nanopore sequencing datasets. A hybrid de novo assembled genome of the Slovenian FD phytoplasma isolate achieved 96% reference genome coverage, with high contiguity and low error rates. This streamlined and accessible protocol enables high-quality genome sequencing of phytoplasma-infected grapevines without the need for propagation in test plants. This facilitates broader phytoplasma research and can potentially be extended to other naturally infected phytoplasma hosts or organisms infected with other non-culturable microbes.
Ključne besede: plant pathogen, nanopore, grapevine, enrichment, HTS, Flavescence dorée, phytoplasma
Objavljeno v DiRROS: 08.10.2025; Ogledov: 355; Prenosov: 186
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Ključne besede: high throughput sequencing, HTS, viruses, metagenomic analysis, doctoral dissertations
Objavljeno v DiRROS: 05.09.2025; Ogledov: 434; Prenosov: 194
Celotno besedilo (8,70 MB)
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Povzetek: Expanding international pet trade has emerged as one of the main introduction pathways of aquatic invasive species, with ornamental crayfish species commonly available on the EU and global markets. Besides most frequently studied crayfish pathogens, such as Aphanomyces astaci and white spot syndrome virus (WSSV), ornamental crayfish carry associated microbial communities, which may potentially lead to the emergence of known or even novel diseases following intentional or unintentional release of animals into the wild. This is especially problematic in the case of viruses, which represent an important, yet considerably understudied, group of crayfish pathogens. Here we analyzed viromes of hepatopancreas tissue of four crayfish species acquired in the international pet trade in Europe (Procambarus clarkii, Procambarus alleni, Cherax holthuisi, and Cherax quadricarinatus) using a high throughput sequencing based metagenomic approach. Seven different known viruses were identified, which were previously either directly associated with crayfish (WSSV, Cherax quadricarinatus reovirus, chequa iflavirus, athtab bunya-like virus) or with hosts from subphylum Crustacea or invertebrates associated with freshwater environment (Shahe ispoda virus 5, Dicistroviridae sp.). Additional sequences represented 8 potential novel and divergent RNA viruses, most similar to sequences belonging to members of Picornavirales, Elliovirales, Reovirales, Hepelivirales, Tolivirales and Ghabrivirales orders. We discuss our findings in relation to their phylogenetic relationships, geographical origins, and putative pathogenicity implications. The results highlight the need for further research into the risks related to disease emergence associated with the pet trade.
Ključne besede: virome, RNA viruses, ornamental crayfish, pet-trade, high throughput sequencing, ecology, molecular biology, pathology, virology, environmental risk assessment
Objavljeno v DiRROS: 23.05.2025; Ogledov: 882; Prenosov: 566
Celotno besedilo (14,36 MB)
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