Ioannis Tzanetakis

• Doctor of Philosophy
• Professor and Director of the Arkansas Clean Plant Center at University of Arkansas at Fayetteville

The commercial cultivation of Andean blackberry (Rubus glaucus Benth) in Ecuador has expanded significantly over the past decade. No certification program exists to ensure the production of planting material free of pathogens of concern. This multi-year study explored the virome of R. glaucus as a first step toward a hazard analysis to identify vir...

This collaborative work by over 180 researchers from 40+ countries addresses the challenges posed by "phantom agents"-putative patho-genic agents named in literature without supporting data on their existence. Those agents remain on regulatory lists, creating barriers in trade and plant certification. Historically identified based solely on symptom...

Emaraviruses are segmented, negative-sense RNA viruses that are transmitted by eriophyoid mites. Advances in virus detection and discovery have significantly improved our understanding of these viruses, yet several challenges persist. This review emphasizes the significant gaps in our knowledge of virus replication, transmission dynamics, and plant...

We developed a dodder-mediated approach to efficiently transfer infectious clones to woody plants, overcoming longstanding challenges in plant virology! Highlights: Significantly outperforms agroinoculation for virus transmission - p-values ranged from 0.005 to 4.09e-06! - Systemic virus: Transmission efficiencies reach 73%, compared to 9% using...

Munger black raspberry (Rubus occidentalis) has been a preferred indicator for Rubus viruses. The working hypothesis behind the Munger elevated susceptibility to viruses is its ability to sustain elevated virus titers; however, no research has yet explored this concept. To address this, we utilized an infectious clone of blackberry chlorotic ringsp...

Woody hosts are notoriously resistant to genetic transformation. Traditional methods, such as Agrobacterium-mediated transformation, are often inefficient, and this limitation extends to delivering infectious clones to woody plants. Dodder species (Cuscuta spp.) are holoparasitic plants that can establish direct connections with the vascular tissue...

Advancements in breeding have facilitated the global expansion of berry cultivation. This expansion has also spread pathogens and diseases, primarily because traditional detection methods often fail to identify asymptomatic pathogen infections, allowing for the propagation of infected material. This communication proposes a systems-based approach u...

A new crinivirus, hereafter referred to as strawberry Kurdistan virus (SKV), has been identified using high-throughput sequencing. The 16,553-nucleotide genome is divided into two RNA segments and exhibits 44–56% nucleotide identity with other criniviruses. Phylogenetic analysis indicates that SKV is a member of the Crinivirus group 2. A diagnostic...

Criniviruses are emerging pathogens responsible for significant disease outbreaks worldwide. Among them, blackberry yellow vein-associated virus (BYVaV) is prevalent in blackberry-producing areas of the United States and, when present in the blackberry yellow vein disease complex with other viruses, can lead to substantial crop losses. To better un...

Blackberry chlorotic ringspot virus (BCRV) was described about 20 years ago and since then there have been several publications of the virus infecting rosaceous hosts including blackberry, raspberry, rose and apple at high rates. Still the effect of the virus on disease development is poorly understood. Aiming to bridge this knowledge gap, we devel...

Understanding the interaction between rose rosette emaravirus (RRV) and its vectors is pivotal in addressing the epidemic outbreak of rose rosette disease. This study employed quantitative real-time RT-PCR to assess RRV genome copy numbers in Phyllocoptes fructiphilus and P. adalius, providing insights into the viral dynamics and vector competency....

Cucurbits (family Cucurbitaceae) includes globally important fruit and vegetable crops. Virus diseases pose a serious threat to cucurbits, limiting crop quality and yield (Regina et al. 2021). In fall 2023, leaf and fruit samples from two squash plants with chlorotic mosaic symptoms and fruit distortion from Monroe and Pope counties in Arkansas wer...

In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished...

A major bottleneck in the development of detection assays is the availability of positive controls. Their acquisition can be problematic, their maintenance is expensive and without them, assays cannot be validated. Herein we present a novel strategy for the development of virus-mimicking artificial positive controls (ViMAPCs). The time between desi...

Screening of blueberry accessions using high throughput sequencing revealed the presence of a new virus. Genomic structure and sequence are similar to that of nectarine stem pitting associated virus (NSPaV), a member of the genus Luteovirus, family Tombusviridae. The full genome of the new luteovirus, tentatively named blueberry virus L (BlVL), was...

A major bottleneck in the development of detection assays is the availability of positive controls. Their acquisition can be problematic; their maintenance is expensive and without them assays cannot be validated. Herein we present a novel strategy for the development of virus-mimicking positive controls (ViMAPCs). The time between design and appli...

Blue cardinal (Lobelia siphilitica L., family: Campanulaceae) is a popular perennial ornamental plant. Lobelia spp. have been reported as hosts of economically important viruses including cucumber mosaic virus (Nameth and Fisher, 2001), turnip mosaic virus (Lockhart et al., 2002), and tomato spotted wilt virus (Brown, 1988). During fall 2022, in a...

Rose rosette devastates the ornamentals industry in the United States. The disease, caused by rose rosette emaravirus (RRV), is vectored by the eriophyoid mite Phyllocoptes fructiphilus (Acari: Eriophyoidea). In this communication, we investigate two other Phyllocoptes species, P. adalius and P. arcani for their vector competency and transmission e...

In March 2022, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by two new families (bunyaviral Discoviridae and Tulasviridae), 41 new genera, and 98 new species. Three hundred forty-nine species were renam...

Currently, many viruses are classified based on their genome organization and nucleotide/amino acid sequence identities of their capsid and replication-associated proteins. Although biological traits such as vector specificities and host range are also considered, this later information is scarce for the majority of recently identified viruses, cha...

In 2020, a novel agent was discovered in strawberry, a rhabdovirus closely related to lettuce necrotic yellows virus. The new virus, named strawberry virus 2 (StrV-2), was discovered in an accession of the Fragaria virus collection of the National Clonal Germplasm Repository (NCGR), and for this reason, it was studied in-depth. The complete StrV-2...

Rubus yellow net virus (RYNV) is a badnavirus that infects Rubus spp. Mixed infections with black raspberry necrosis virus and raspberry leaf mottle virus cause raspberry mosaic, a disease that leads to significant losses and even plant death. RYNV has been reported in several European countries and the Americas yet there is substantial lack of kno...

Strawberry (Fragaria x ananassa) is the most important berry crop worldwide and viruses pose a constant threat to the industry. In this communication, we describe a novel virus in the family Rhabdoviridae referred to as strawberry virus 3 (StrV-3). The virus does not show significant homology when compared to recognized rhabdoviruses and therefore...

A small-scale survey for blueberry viruses in Bosnia and Herzegovina was performed in 2018. A total of 20 samples from three locations were collected and analyzed for the presence of 11 viruses. ELISA assays were performed for blueberry scorch virus, blueberry shock virus, blueberry shoestring virus, blueberry leaf mottle virus, tobacco ringspot vi...

Potyviridae, the largest family of known RNA viruses (realm Riboviria), belongs to the picorna-like supergroup and has important agricultural and ecological impacts. Potyvirid genomes are translated into polyproteins, which are in turn hydrolyzed to release mature products. Recent sequencing efforts revealed an unprecedented number of potyvirids wi...

Rubus yellow net virus (RYNV) is a badnavirus that infects Rubus spp. In mixed infections with black raspberry necrosis and raspberry leaf mottle they cause raspberry mosaic, a disease that leads to significant losses and even plant death. RYNV has been reported in several European countries and the Americas yet there is substantial lack of knowled...

This datasheet on Tobacco streak virus covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Vectors & Intermediate Hosts, Diagnosis, Biology & Ecology, Seedborne Aspects, Impacts, Prevention/Control, Further Information.

This datasheet on Strawberry necrotic shock virus covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Vectors & Intermediate Hosts, Diagnosis, Biology & Ecology, Seedborne Aspects, Impacts, Prevention/Control, Further Information.

This book contains 19 chapters providing information on fig ( Ficus carica ) botany, production, processing, nutritive value and marketing.

Cycas necrotic stunt virus (CNSV) has an extensive host range and is detected in an accelerated pace around the globe in several agricultural crops. One of the plant species affected is peony (Paeonia lactiflora Pall.). The virus is asymptomatic in most peony cultivars, but there have been reports of symptoms in others. It is thus important to stud...

Lemoine's disease of peonies (LDP) is associated with root galls that could lead to stunted growth and reduced flowering. In the quest to identify the causal agent(s) of LDP, two symptomatic plants (cv. Alice Crousse [AC] and Alice Harding [AH]) were sampled in Arkansas in 2019 and sequenced as described (Shaffer et al., 2019). Gentian Kobu-sho-ass...

In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, a...

In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, a...

There are few plant maladies as devastating as rose rosette, a disease caused by an eriophyoid -transmitted virus. Rosette annihilates roses across North America, and to date, there is a single verified vector of the virus, Phyllocoptes fructiphilus Keifer. In direct contrast to the importance of rose for the ornamental industry there is limited kn...

HTS compared with standard methods. Through this research it is clear that testing once is not enough..

A comprehensive study comparing virus detection between high throughput sequencing (HTS) and standard protocols in 30 berry selections (12 Fragaria, 10 Vaccinium and 8 Rubus) with known virus profiles was completed. The study examined temporal detection of viruses at four sampling times encompassing two growing seasons. Within the standard protocol...

There are few plant maladies as devastating as rose rosette, a disease caused by an eriophyoid -transmitted virus. Rosette annihilates roses across North America, and to date, there is a single verified vector of the virus, Phyllocoptes fructiphilus Keifer. In direct contrast to the importance of rose for the ornamental industry there is limited kn...

Cycas necrotic stunt virus (CNSV) has an extensive host range and is detected in an accelerated pace around the globe in several agricultural crops. One of the plant species affected is peony (Paeonia lactiflora Pall.). The virus is asymptomatic in most peony cultivars, but there have been reports of symptoms in others. It is thus important to stud...

Rubus yellow net virus (RYNV) belongs to genus Badnavirus. Badnavirids are found in plants as endogenous, inactive sequences, and/or in episomal (infectious and active) forms. To assess the state of RYNV infections, we sequenced the genomes of various Rubus cultivars and mined eight additional published whole genome sequencing datasets. Sequence an...

Published in Virus Research - http://dx.doi.org/10.1016/j.virusres.2021.198468

Lychnis mottle virus (LycMoV), family Secoviridae, is one of several viruses recently detected in peony. Given the high prevalence of the virus in the more than 300 samples tested, the population structure of the virus was studied using 48 isolates representing at least 20 cultivars and collected from major producing and propagating states in the U...

Citrus yellow-vein disease (CYVD) was first reported in California in 1957. We now report that CYVD is associated with a virus-like agent, provisionally named citrus yellow-vein associated virus (CYVaV). The CYVaV RNA genome has 2,692 nucleotides and codes for two discernable open reading frames (ORFs). ORF1 encodes a protein of 190 amino acid (aa)...

An unprecedented number of viruses have been discovered by leveraging advances in high-throughput sequencing. Infectious clone technology is a universal approach that facilitates the study of biology and role in disease of viruses. In recent years homology-based cloning methods such as Gibson assembly have been used to generate virus infectious clo...

p>In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted...

This article provides an up-to-date review of disease causing viruses and phytoplasmas of currants including symptoms, transmission, detection, economic impact and control measures. Currants are widely cultivated in more than 30 countries in the temperate zones of Europe, Asia, South America, Australia and New Zealand. Ribes spp. can be infected by...

Pathogen-tested foundation plant stocks are the cornerstone of sustainable specialty crop production. They provide the propagative units that are used to produce clean planting materials, which are essential as the first-line management option of diseases caused by graft-transmissible pathogens such as viruses, viroids, bacteria and phytoplasmas. I...

Lemoine’s disease of peony (LDP) symptoms include root galliing and stunted growth, making it a major concern for the peony industry (Garfinkel and Chastagner 2016). In an effort to elucidate the causal agent of the disease three viruses (citrus leaf blotch, cycas necrotic stunt, and lychnis mottle) have previously been detected in peony (Paeonia l...

Raspberry leaf blotch virus (RLBV) is the putative agent of the homonymous disease and even though Bosnia and Herzegovina is a major producer worldwide there is no report of the virus presence in the country. We studied the virus population structure and assessed its ability to move systemically. RLBV is widespread in production areas and has a hom...

A new member of the family Secoviridae was discovered in a symptomatic American blackcurrant plant. In-silico analysis of the genome of the virus, blackcurrant waikavirus A (BCWVA), predicted two open reading frames (ORFs). ORF1 encodes a polyprotein with conserved domains of a leader protein, three capsid proteins, a superfamily 3 viral helicase,...

Rose rosette virus (RRV) (genus Emaravirus), is the causal agent of the homonymous disease, the most destructive malady of roses in the United States. Although the importance of the disease is recognized there is little sequence information and no full genomes of RRV, a multi-segmented RNA virus, available. To better understand the population struc...

We recently completed the Special Issue on ‘Plant Virus Epidemiology and Control’. As editors, we decided not to offer vouchers to scientists that submit to this issue. This action had an effect on the number of papers received and accepted. We received a total of 19 papers and we accepted four [...]

We present a taxonomic proposal for revision of the family Secoviridae, a taxon of plant viruses in the order Picornavirales. We propose the reorganization of the genus Sadwavirus to create three new subgenera and to update the classification of five existing species. The proposed subgenera are “Satsumavirus” (one species: Satsuma dwarf virus), “St...

The family Amalgaviridae, part of the realm Riboviria was recognized by the International Committee on Taxonomy of Viruses (ICTV) in 2014. The family includes viruses infecting plants and fungi (yeasts) with a non-segmented, bicistronic dsRNA genome of 3.1–3.5 kbp and is currently composed of two genera: Amalgavirus and Zybavirus. The 5′ proximal O...

Soybean vein necrosis virus (SVNV), the causal agent of the homonymous disease, is a ubiquitous virus in North America. The widespread presence of the virus has led to the hypothesis that mixed infections with other viruses could alter disease symptoms, localization in the plant and even epidemiology. The potential interaction between bean pod mott...

Orthotospoviruses are acquired by thrips during feeding on infected tissue. Virions travel through the foregut and enter midgut epithelial cells through the interaction between the viral glycoproteins and cellular receptors. Glycoprotein RGD motifs and N-linked glycosylation sites have been predicted to mediate receptor binding or play important ro...

The prevalence of soybean vein necrosis virus (SVNV) in soybean (Glycine max (L.), Merr.) across major producing areas in North America and its negative impact on seed oil content demonstrate the need for effective control strategies against the virus. Varieties with resistance to vectors could modify their behavior, reduce transmission and consequ...

Eriophyoids affect crops around the globe directly or indirectly as virus vectors. Eriophyoid systematics initiated over a century ago, yet more than 90% of their fauna remain undescribed. Morphological identification is challenging because of a limited number of traits, cryptic speciation and complex life cycle reported for many species in the gro...

Over the last decade, virologists have discovered an unprecedented number of viruses using high throughput sequencing (HTS), which led to the advancement of our knowledge on the diversity of viruses in nature, particularly unraveling the virome of many agricultural crops. However, these new virus discoveries have often widened the gaps in our under...

Few diseases have emerged in such a short period of time as soybean vein necrosis. The disease is present in all major producing areas in North America, affecting one of the major row field instead of row crops for the United States. Because of the significance of soybean in the agricultural economy and the widespread presence of the disease, the c...

Reversion disease, thought to be caused by the eriophyid mite transmitted blackcurrant reversion virus (BRV), is the most economically important disease of black currants (Ribes nigrum L.) and can be found nearly everywhere blackcurrants are cultivated except North America and Australia (Jones & McGavin, 2002; Lemmetty et al., 1997; Susi, 2004). BR...

The causal agent of Lemoine’s disease of peony (Paeonia lactiflora Pall.) (LDP) remains unknown (Garfinkel and Chastagner, 2016). Plants from Arkansas with typical LDP symptoms were subjected to highthroughput sequence analysis as previously described (Gress et al. 2017). Two viruses that have never been identified in peony in North America, cycas...

A novel virus with distinct genome features was discovered by high throughput sequencing in a symptomatic blackcurrant plant. The virus, tentatively named Ribes americanum virus A (RAVA), has distinct genome organization and molecular features bridging genera in the order Tymovirales. The genome consists of 7106 nucleotides excluding the poly(A) ta...

In 2018, the family Arenaviridae was expanded by inclusion of 1 new genus and 5 novel species. At the same time, the recently established order Bunyavirales was expanded by 3 species. This article presents the updated taxonomy of the family Arenaviridae and the order Bunyavirales as now accepted by the International Committee on Taxonomy of Viruses...

Peony, Paeonia lactiflora, Pall. is a perennial ornamental grown around the globe. Lemoine described a disease in the early 1900s with symptoms that include root galls, reduced flowering, and stunted growth with the causal agent remaining elusive. Large scale sequencing was employed to determine whether a virus is associated with the symptoms. Abou...

Five isolates of a new member of the family Closteroviridae, tentatively named blackcurrant leafroll-associated virus 1 (BcLRaV-1), were identified in the currant. The 17-kb-long genome codes for 10 putative proteins. The replication-associated polyprotein has several functional domains, including papain-like proteases, methyltransferase, Zemlya, h...

Blackberries exhibiting yellow vein disease symptoms were found to be infected by a new virus, a putative member of the genus Vitivirus. Recombination assessment of several vitiviruses revealed multiple events involving the newly identified virus isolate. Occurrence in areas of high disease pressure was investigated and the population structure was...

There is limited information on the distribution of blueberry viruses in the U.S. or around the world other than where the viruses were first discovered and characterized. A survey for blueberry viruses was carried out in the U.S. in 2015⁻2017. Most blueberry viruses have been characterized to the point that sensitive diagnostic assays have been de...

Five isolates of a new putative member of the genus Closterovirus, tentatively named blackcurrant leafroll associated virus 1 (BcLRaV-1), were identified in currant. The 17 kb long genome of BcLRaV-1 contained 10 open reading frames (ORFs). The replication associated polyprotein has two papain-like leader proteases, a methyltransferase, a helicase...

The Potyviridae family is a major group of plant viruses that includes ca. 200 species, most of which have narrow host ranges. The potyvirid P1 leader proteinase self-cleaves from the remainder of viral polyprotein and shows large sequence variability linked to host adaptation. P1 proteins can be classified as Type A or Type B based, among other th...

A novel virus with distinct genome features was discovered by high throughput sequencing in a symptomatic blackcurrant plant. The virus tentatively named as blackcurrant virus A (BCVA) has distinct genome organization and molecular features bridging genera in the order Tymovirales. The genome consists of 7106 nucleotides excluding the poly(A) tail....

Peonies have been plagued for a hundred years by a disease that causes reduced flowering, stunted growth, and galling of the roots. The biology of Lemoine’s disease remains a mystery and the cause biotic or abiotic, has not been determined. Cycas necrotic stunt virus (CNSV), a member of the genus Nepovirus, has been found in 90% of 200 leaf samples...

Pilot studies to evaluate the feasibility and effectiveness of the proposed National Blueberry Certification Scheme are underway in three states with a tradition in blueberry propagation (Michigan, Oregon and Washington). The guidelines describe propagation, testing and maintenance procedures at four stages (generations - G-levels) in the certifica...

Blueberry mosaic associated virus (BlMaV), the presumed causal agent of the homonymous disease and blackberry vein banding associated virus (BVBaV), a component of the blackberry yellow vein disease complex, are recently characterized RNA viruses. There is a need for efficient and sensitive detection protocols for the two viruses, not only for scre...

The Ophioviridae is a family of filamentous plant viruses, with single-stranded negative, and possibly ambisense, RNA genomes of 11.3-12.5 kb divided into 3-4 segments, each encapsidated separately. Virions are naked filamentous nucleocapsids, forming kinked circles of at least two different contour lengths. The sole genus, Ophiovirus, includes sev...