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This study was initiated to examine the tomato-infecting viruses belonging to the Tobamovirus and Potexvirus genera in Iraq. Field observations and surveys were carried out for three successive cropping seasons (2020/21 to 2022/23) in selected tomato production areas. The purpose was to identify the main viruses associated with tomato epidemics and assess the impact of different tomato cultivars on disease occurrence. A total of 700 tomato leaf samples were collected from seven governorates (Baghdad, Diyala, Babylon, Najaf, Kerbala, Nasiriya, and Basrah) and tested using pathogen-specific immunostrip kits. The survey showed a presence of Tomato brown rugose fruit virus (ToBRFV), Tobacco mosaic virus (TMV), Pepper mild mottle virus (PMMoV), Cymbidium mosaic virus (CymMV), Odontoglossum ringspot virus (ORSV), Cucumber green mottle mosaic virus (CGMMV), Pepino mosaic virus (PepMV) and Potato virus X (PVX) in tomato fields in Iraq. ToBRFV secured the highest relative incidence in tomato fields (7 governorates) followed by PepMV and CymMV and PMMoV (6 out of 7 governorates) and CGMMV, TMV (5 governorates), and PVX (3 governorates). The least was ORSV (only in Basrah). To our knowledge, this is the first comprehensive survey investigating Tobamovirus and Potexvirus on tomato fields in Iraq and the first report of ToBRFV, PMMoV, CymMV, ORSV, CGMMV and PepMV infecting tomato crops in Iraq. [ABSTRACT FROM AUTHOR]

Orchids are significant ornamental plants whose viral infection results in substantial economic damage. Cymbidium mosaic virus (CymMV), Odontoglossum ringspot virus (ORSV), and Cymbidium ringspot virus (CymRSV) represent three important and prevalent orchid viruses. The detection system proposed in this study uses a triplex TaqMan quantitative real-time PCR assay to identify CymMV, ORSV, and CymRSV in a simultaneous manner. We designed specific primers and probes for CymMV, ORSV, and CymRSV, with amplified sequences of 156 bp, 148 bp, and 145 bp, respectively. The minimum detection limit of the triplex qRT-PCR assay for CymMV and CymRSV was 1 copy/assay, and the minimum detection limit was 10 copies/assay for ORSV. The minimum stable detection limits for CymMV, ORSV, and CymRSV were 10, 10², and 10² copies/assay, respectively. Therefore, this system exhibited higher sensitivity (approximately 10 to 104-fold) than RT-- PCR. The intra-and interassay CVs of Cq values are less than 0.55 and 0.95%, respectively, indicating that the triplex assay is highly reliable and accurate. In addition, 66 samples from five different orchid genera were analyzed using the established assay and gene chip. The detection results demonstrated that the triplex probe qRT--PCR demonstrated higher sensitivity than the gene chip, indicating that the triplex real-time PCR assay could be used for the detection of field samples. Our findings suggest that the triplex real-time RT--PCR detection system represents a rapid, simple, and accurate tool for detecting CymMV, ORSV, and CymRSV on orchids. [ABSTRACT FROM AUTHOR]

• PCR-based techniques are the most widely used diagnostic tools for virus indexing. • Out of 681 total genera, only 49 genera were reported for virus infection. • Cypripedioideae is the most affected among the sub-family in Orchidaceae. • Production of Virus-free orchids using in vitro techniques is a desirable approach. The maximum number of genera in the family Orchidaceae are well represented by their floricultural importance and are exported globally for trade exchanges. However, economic loss due to viral diseases has a profound impact on the orchid trade industry worldwide. Further, enduring phytosanitary certificates and undergoing stringent quarantine measures for virus-free orchids pose a major setback during the exchange of breeding materials between regions or countries. Fortunately, the spread of orchid viruses can be effectively controlled if proper diagnosis of viral diseases is made at an early stage and strict application of appropriate eradication methods are deliberated in a holistic approach. This bibliographic review highlights the substantial advancements in the diagnostic and eradication techniques of orchid viruses during the past few decades. The review shows that PCR-based techniques, which are represented as the "gold standard" method, are the most widely used diagnostic tools because of their accuracy, simplicity, and sensitivity. Considering the large diversity of orchids, only 7.2% of the genera belonging to the sub-families Epidendroideae, Orchidoideae, Cypripedioideae, and Vanilloideae have been detected for virus infection. The tribes Podochileae, Thaieae, Nervilieae, Gastrodieae, Xerorchideae, Triphoreae, Wullschlaegelieae, Tropidieae, Sobralieae, and Neottieae of the family Orchidaceae are under-represented. In vitro techniques, including meristem culture, thermotherapy, chemotherapy, and their combinations, represent the most desirable and effective approaches for orchid viral elimination. The use of cryotherapy, a simple technique based on cryopreservation, should have a high priority for viral elimination from infected orchids. This review could pave the way forward for comprehensive research on the production of virus-free orchids. [ABSTRACT FROM AUTHOR]

• ORSV was found to be more prevalent than CymMV with the incidence percentages of 53.5% and 46.4% respectively. • Mixed infection of ORSV and CymMV was found to be 35.7%. • The Nucleotide sequences of ORSV and CymMV CP genes from Meghalaya showed high sequence identities of 96.90–99.56% and 96.91–99.66% respectively with other available sequences in Genbank. Odontoglossum ringspot virus (ORSV) and cymbidium mosaic virus (CymMV) are the most prevalent viruses infecting orchids all around the world. These viruses cause a serious threat to the orchid industry as they can spread from infected plants to healthy plants through vegetative propagation, contaminated tools, and human hands. This result in negative vigour of infected plants, showing stunted growth, producing fewer flowers, and decreasing flower quality. In this study, 84 leaf samples of orchids were collected from nine horti-hubs and orchid nurseries in Meghalaya. The orchid leaf samples were subjected to multiplex RT-PCR amplification using gene-specific primers targeting the coat protein (CP) genes of CymMV and ORSV. The most prevalent virus detected was ORSV with a 53.5% incidence while CymMV showed a 46.4% incidence. Mixed infections of ORSV and CymMV were detected in 30 samples (35.7%). The nucleotide sequences of ORSV and CymMV CP genes from Meghalaya showed high sequence identities of 96.90–99.56% and 96.91–99.66%, respectively when compared to other sequences in GenBank. The phylogenetic relationship among ORSV isolates and CymMV, based on infected host or geographical origin, showed no clear-cut clustering of isolates. [ABSTRACT FROM AUTHOR]

Plant ARGONAUTES (AGOs) play a significant role in the defense against viral infection. Previously, we have demonstrated that AGO5s encoded in Phalaenopsis aphrodite subsp. formosana (PaAGO5s) took an indispensable part in defense against major viruses. To understand the underlying defense mechanism, we cloned PaAGO5s promoters (pPaAGO5s) and analyzed their activity in transgenic Nicotiana benthamiana using β-glucuronidase (GUS) as a reporter gene. GUS activity analyses revealed that during Cymbidium mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV) infections, pPaAGO5b activity was significantly increased compared to pPaAGO5a and pPaAGO5c. Analysis of pPaAGO5b 5′-deletion revealed that pPaAGO5b_941 has higher activity during virus infection. Further, yeast one-hybrid analysis showed that the transcription factor NbMYB30 physically interacted with pPaAGO5b_941 to enhance its activity. Overexpression and silencing of NbMYB30 resulted in up- and downregulation of GUS expression, respectively. Exogenous application and endogenous measurement of phytohormones have shown that methyl jasmonate and salicylic acid respond to viral infections. NbMYB30 overexpression and its closest related protein, PaMYB30, in P. aphrodite subsp. formosana reduced CymMV accumulation in P. aphrodite subsp. formosana. Based on these discoveries, this study uncovers the interaction between virus-responsive promoter and the corresponding transcription factor in plants. [ABSTRACT FROM AUTHOR]

Orchids (Orchidaceae) are one of the most popular ornamental plants having diverse flower shapes and colors. They are vastly applied as cut flowers, potted plants, and garden elements. Infectious diseases are still a major obstacle in the cultivation of orchids in Indonesia. Odontoglossum ringspot virus (ORSV) is one of the most widely reported viruses that infect orchids worldwide, including Indonesia. This research was done by mechanically injecting the virus on Phalaenopsis amabilis and Dendrobium Salaya Fancy. This study aimed to determine the symptoms of the disease, plant resistance, and chlorophyll content. The results showed that each orchid had severe disease symptoms, the incidence of both orchids was 80%, and Phalaenopsis amabilis reaction was more susceptible than Dendrobium Salaya Fancy that showed tolerant response to ORSV. Physiological response analysis also showed that the content of chlorophyll A,B, and total Dendrobium Salaya Fancy was higher (0.35 ± 0.02; 0.29 ± 0.05; 0.63 ± 0.05) than Phalaenopsis amabilis (0, 18 ± 0.0; 0.31 ± 0.06; 0.48 ± 0.04) respectively, after viral infection. This proves that Phalaenopsis is the most susceptible type of orchid virus compared to Dendrobium. [ABSTRACT FROM AUTHOR]

Cymbidium mosaic virus and Odontoglossum ringspot virus are the most common and widespread viruses in ornamental orchids. Infections caused by these viruses can lead to a decrease in the phenotypic diversity of orchid collections, and as a result – to their complete depletion. The aim of the study is to determine the origin of Ukrainian isolates of orchid viruses in the collection of protected soil from O.V. Fomin Botanical Garden of Taras Shevchenko National University of Kyiv. The properties of nucleotide and amino acid sequences of the coat proteins (CP) of Cymbidium mosaic virus (CymMV) and of Odontoglossum ringspot virus (ORSV) were investigated. RNAs of CymMV and ORSV were isolated from leaves of Phalaenopsis sp. collected from A.V. Fomin Botanical Garden of Taras Shevchenko National University of Kyiv, amplified through RT-PCR and sequenced. Obtained sequences were compared at nucleotide and amino acid levels with CymMV and ORSV isolates available in the GenBank. ORSV isolated in Ukraine shared 96-99 % and 93,4-98 % CP similarity to other known ORSV isolates at nucleotide and amino acid levels, respectively. CymMV isolated in Ukraine revealed approximately 77-97 % similarity for nucleotide sequences and 84-100 % for amino acid sequences to isolates from the GenBank. Phylogenetic analysis showed that studied ORSV and CymMV isolates may have common origin with some South Korean isolates. [ABSTRACT FROM AUTHOR]

Societal Impact Statement Orchid viruses are capable of causing flower deformities and death, which can severely impact the horticultural industry and wild orchid conservation. Here we show how two of these quickly evolving viruses display few genetic differences since their first emergence, across countries and host plants. This is concerning as, despite biosecurity regulations to control the movement of orchids and their related pathogens, these patterns are suggestive of rapid and regular international movement of horticultural material. Poor biosecurity practices could threaten the orchid horticultural industry and result in the accidental translocation or reintroduction of infected plant material intended to recover wild populations.

Interplay between Cymbidium mosaic virus (CymMV)/Odontoglossum ringspot virus (ORSV) and its host plant Phalaenopsis equestris remain largely unknown, which led to deficiency of effective measures to control disease of P. equestris caused by infecting viruses. In this study, for the first time, we characterized viral small interfering RNAs (vsiRNAs) profiles in P. equestris co-infected with CymMV and ORSV through small RNA sequencing technology. CymMV and ORSV small interfering RNAs (siRNAs) demonstrated several general and specific/new characteristics. vsiRNAs, with A/U bias at the first nucleotide, were predominantly 21-nt long and they were derived predominantly (90%) from viral positive-strand RNA. 21-nt siRNA duplexes with 0-nt overhangs were the most abundant 21-nt duplexes, followed by 2-nt overhangs and then 1-nt overhangs 21-nt duplexes in infected P. equestris. Continuous but heterogeneous distribution and secondary structures prediction implied that vsiRNAs originate predominantly by direct Dicer-like enzymes cleavage of imperfect duplexes in the most folded regions of the positive strand of both viruses RNA molecular. Furthermore, we totally predicted 54 target genes by vsiRNAs with psRNATarget server, including disease/stress response–related genes, RNA interference core components, cytoskeleton-related genes, photosynthesis or energy supply related genes. Gene Ontology classification showed that a majority of the predicted targets were related to cellular components and cellular processes and performed a certain function. All target genes were down-regulated with different degree by vsiRNAs as shown by realtime reverse transcription polymerase chain reaction. Taken together, CymMV and ORSV siRNAs played important roles in interplay with P. equestris by down modulating the expression levels of endogenous genes in host plant.

Ninety-six symptomatic orchids representing 36 genera from seven orchid collections, including two conservatories, in Minnesota, USA were tested for cymbidium mosaic virus (CymMV), odontoglossum ringspot virus (ORSV), and orchid fleck virus (OFV) using dipsticks (CymMV and ORSV), RT-PCR (OFV), and transmission electron microscopy (all viruses). CymMV was identified in 22% of the samples, OFV was identified in 17% of the samples, and ORSV was detected in 6% of the samples. Five percent of samples were infected with both CymMV and ORSV and 1% of samples were infected with both OFV and ORSV. Characteristic orchid virus symptoms of chlorotic and necrotic patterns were observed for the majority of infected orchids. Polyclonal antibodies were produced against Escherichia coli expressed OFV phosphoprotein (OFV P) and evaluated for use in plate trapped antigen-enzyme linked immunosorbent assay (PTA-ELISA). After an overnight incubation with PNPP the OFV P polyclonal antisera diluted from 1:1000–1:20,000 (v/v) readily differentiated between fresh healthy and OFV infected orchid (Phalaenopsis hybrid) tissue diluted from 1:5–1:20 (w/v). The high incidence of viruses detected in orchids (50%) suggests limited use of certified virus-free propagation stock and highlights the importance of sanitation to prevent transmission between plants. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Orchid viruses are capable of causing flower deformities and death, which can severely impact the horticultural industry and wild orchid conservation. Here we show how two of these quickly evolving viruses display few genetic differences since their first emergence, across countries and host plants. This is concerning as, despite biosecurity regulations to control the movement of orchids and their related pathogens, these patterns are suggestive of rapid and regular international movement of horticultural material. Poor biosecurity practices could threaten the orchid horticultural industry and result in the accidental translocation or reintroduction of infected plant material intended to recover wild populations. [ABSTRACT FROM AUTHOR]

Natural orchids are one of the important ornamental plants that were cultivated in tropical countries, including Indonesia. Virus infections has been important limiting factor in orchids cultivation because it decreases the orchids quality. Odontoglossum ringspot virus (ORSV) is one of the most reported virus infecting orchids which spread widely in the world. During 2010–2014 surveys of viral infections were conducted in Indonesia. The orchids were found infected by virus, showed symptoms of mosaic, mottle, chlorotic, necrotic, streak, wilting leaf, and ringspot on leaf surface. Detection with serological test DAS-ELISA showed only 11 from 125 samples were infected by ORSV with total incidence of 8,8%. Nine leaf samples of Phalaenopsis sp. were infected, respectively. Thus, it was concluded that Phalaenopsis is orchids genus which is the most abundantly and susceptibly infected by ORSV. The results proved that ORSV have entered and spread widely by infected orchids in orchids landscape (nursery), semi-natural forests (botanical gardens), and natural forest (national park) throughout Indonesia. This is the first report of ORSV infecting natural tropical orchids in Indonesia. INTISARI Anggrek alam merupakan salah satu kekayaan flora asli negara tropis, termasuk Indonesia. Keberadaan di habitat aslinya sudah sangat berkurang yang disebabkan kerusakan hutan dan adanya penyakit. Infeksi virus masih menjadi faktor pembatas terpenting dalam budidaya dan pengembangan potensi anggrek alam. Odontoglossum ringspot virus (ORSV) adalah salah satu jenis virus yang dilaporkan paling banyak menginfeksi anggrek serta memiliki penyebaran yang luas di dunia. Selama 2010-2014 telah dilakukan survei lapangan terhadap infeksi virus di Indonesia. Beberapa anggrek yang ditemukan terinfeksi oleh virus menunjukkan gejala berupa mosaik, belang, klorosis, nekrosis, streak, daun layu, dan bercak cincin pada permukaan daun. Deteksi dengan uji serologis DAS-ELISA menunjukkan bahwa 11 dari 125 sampel terinfeksi oleh ORSV dengan total kejadian 8,8%. Masing-masing sembilan dari total sampel daun terinfeksi merupakan Phalaenopsis sp. Hal ini menjelaskan bahwa Phalaenopsis adalah genus anggrek yang paling cocok dan rentan terhadap infeksi ORSV. Hasil penelitian survei kejadian infeksi Odontoglossum ringspot virus (ORSV) membuktikan bahwa virus ini telah masuk dan menyebar secara luas oleh anggrek-anggrek alam tropis yang terinfeksi di pertamanan anggrek (nurseri), hutan semi-alami (kebun raya), dan hutan alam (taman nasional) di seluruh wilayah Indonesia. Ini merupakan laporan pertama mengenai infeksi ORSV terhadap anggrek-anggrek alam tropis di Indonesia.

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The micropropagation efficiency of four interspecific Cattleya hybrids (clones: 69, 75, 149 and 150) infected with Cymbidium mosaic (CyMV) and Odontoglossum ringspot (ORSV) viruses was assessed. The aim of experiments was to evaluate with that model to what extent viral infection affects the morphogenesis in vitro in orchid hybrids of different origin. The effectiveness of plant material exposure to therapeutic levels of plant growth regulators supplied with media in order to suppress infection was also verified. The vitality of proliferating infected shoot cultures was limited, and the symptoms of senility were frequently observed. Regardless genotype of the studied clone, during acclimation to ex vitro conditions considerable losses become visible what indicates the necessity of testing the donor material for possible latent viral infections. Infection with CyMV and ORSV mostly persisted in every tested clone.

The article reports on the virus that affect orchids. It states that orchids are constantly infected with pathogenic agents that decrease their quality and attractiveness. The most important and most prevalent among the virus identified are the Tobamovirus Odontoglossum ringspot virus (ORSV) and the Potexvirus Cymbidium mosaic virus (CymMV). The author notes on the study made on the Cattleya hybrid from the Revenga provinces in Venezuela to identify the causal agent of the symptomatology.

Early detection of pathogens is crucial for the effective surveillance of diseases. Many efforts have been made to explore methods which can detect these pathogens within a short period of time without requiring a tedious protocol. However, these developed methods have disadvantages such as they are relatively time-consuming or require specialized laboratory facilities. In this work, we have developed an integrated microfluidic system for rapid and automatic detection of viruses by direct analysis from fresh Phalaenopsis orchid leaves. The entire protocol, including ribonucleic acid (RNA) purification, reverse transcription loop-mediated-isothermal-amplification (RT-LAMP) and optical detection by measuring changes in turbidity was performed on a single chip. This is the first time that an integrated microfluidic system for the detection of viruses infecting the Phalaenopsis orchid has been demonstrated. The sensitivity of the developed system was also explored in this study to validate its performance., From the Clinical Editor: In this study, the authors report the development of an integrated microfluidic system for rapid and automatic detection of viruses by direct analysis of fresh Phalaenopsis orchid leaves, performing the 3-step protocol using a single chip. Similar methods may find clinical application for fast and accurate detection of viral infections., (Copyright © 2013 Elsevier Inc. All rights reserved.)