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These 10 PVY isolates had one to four amino acid differences from the epitope recognized by MAb N1 but contained the epitope recognized by M1 and M2. Keywords: cocktail; detection; epitope; monoclonal antibody; potato virus Y; serology EN cocktail detection epitope monoclonal antibody potato virus Y serology 1725 1727 3 08/23/23 20230901 NES 230901 Antibody-based serological methods, including enzyme-linked immunosorbent assay (ELISA), dot immunobinding assay (DIBA) and Western blot, play an essential role in the detection of plant viruses. [Extracted from the article]

Potato (Solanum tuberosum L) is affected by several viral pathogens with the most economically damaging being potato virus Y (PVY). At least nine biologically distinct variants of PVY are known to attack potato, with necrotic types named PVYNTN and PVYN-Wi being the most recent additions to the list. So far, the molecular plant-virus interactions underlying this pathogenicity are not fully understood. In this study, gas chromatography coupled with mass spectroscopy (GC–MS) was used for an untargeted investigation of the changes in leaf metabolomes of PVY-resistant cultivar Premier Russet, and a susceptible cultivar, Russet Burbank, following inoculation with three PVY strains, PVYNTN, PVYN-Wi, and PVYO. Analysis of the resulting GC–MS spectra with the online software Metaboanalyst (version 5.0) uncovered several common and strain-specific metabolites that are induced by PVY inoculation. In Premier Russet, the major overlap in differential accumulation was found between PVYN-Wi and PVYO. However, the 14 significant pathways occurred solely due to PVYN-Wi. In contrast, the main overlap in differential metabolite profiles and pathways in Russet Burbank was between PVYNTN and PVYO. Overall, limited overlap was observed between PVYNTN and PVYN-Wi. As a result, PVYN-Wi-induced necrosis may be mechanistically distinguishable from that of PVYNTN. Furthermore, 10 common and seven cultivar-specific metabolites as potential indicators of PVY infection and susceptibility/resistance were identified by using PLS-DA and ANOVA. In Russet Burbank, glucose-6-phosphate and fructose-6-phosphate were particularly affected by strain–time interaction. This highlights the relevance of the regulation of carbohydrate metabolism for defense against PVY. Some strain- and cultivar-dependent metabolite changes were also observed, reflecting the known genetic resistance–susceptibility dichotomy between the two cultivars. Consequently, engineering broad-spectrum resistance may be the most effective breeding strategy for managing these necrotic strains of PVY. [ABSTRACT FROM AUTHOR]

The ubiquitin–proteasome system (UPS) plays an important role in virus–host interactions. However, the mechanism by which the UPS is involved in innate immunity remains unclear. In this study, we identified a novel major latex protein-like protein 43 (NbMLP43) that conferred resistance to Nicotiana benthamiana against potato virus Y (PVY) infection. PVY infection strongly induced NbMLP43 transcription but decreased NbMLP43 at the protein level. We verified that B-box zinc finger protein 24 (NbBBX24) interacted directly with NbMLP43 and that NbBBX24, a light responsive factor, acted as an essential intermediate component targeting NbMLP43 for its ubiquitination and degradation via the UPS. PVY, tobacco mosaic virus, (TMV) and cucumber mosaic virus (CMV) infections could promote NbMLP43 ubiquitination and proteasomal degradation to enhance viral infection. Ubiquitination occurred at lysine 38 (K38) within NbMLP43, and non-ubiquitinated NbMLP43(K38R) conferred stronger resistance to RNA viruses. Overall, our results indicate that the novel NbMLP43 protein is a target of the UPS in the competition between defense and viral anti-defense and enriches existing theoretical studies on the use of UPS by viruses to promote infection. [ABSTRACT FROM AUTHOR]

Potato virus Y (PVY) is one of the common viruses in potato production. Detection of potato virus is an important basis for safeguarding potato quality and yield in production. Batch detection after harvest is one of the main bases for seed potato quality evaluation. In this study, dormant tuber samples from the potato varieties (lines) of '56-2', 'Ivory Russet', 'Clearwater Russet', 'Longshu 14', 'Longshu 3', 'Longshu 15', 'Longyu 201401-70', 'Longshu 7', 'Kexin 23' and 'Kexin 28' were used to extract the total RNA in bud eyes tissues of apical end and stolon end by TRIzol method. The distribution of PVY content in bud eyes tissues of the apical end and stolon end was compared by qRTPCR and RT- PCR detection analysis. The PVY concentration in bud eyes tissues of the stolon end of the tested varieties (lines) was higher than that in the apical end, indicating that the presence of the virus could be accurately detected in stolon end. One hundred diseased tuber samples were selected from the dormant tubers of 'Ivory Russet', and the total RNA in eye tissues of the apical end and stolon end was extracted by TRIzol method. The samples were combined by 4 in 1 method for PVY RT-PCR detection. The band brightness of apical end was lower than that of stolon end in all treatments, indicating that PVY could be detected more accurately using stolon end sample than apical end in dormant tubers. The results of this study provide a scientific basis for the reasonable sampling and detection of PVY after seed potato harvest. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is one of the main food crops worldwide, including in Kazakhstan. Viral diseases are a major constraint to sustainable potato production, as they cause large losses in crop quantity and quality. To determine the current status of potato production in Kazakhstan, we studied tuber and leaf samples in large seed and commercial farms of the Republic. Samples of tuber and leaf samples randomly sampled were tested for five main viruses: potato virus Y (PVY), potato virus X (PVX), potato virus M (PVM), potato virus S (PVS), and potato leafroll virus (PLRV). A multiplex reverse transcription polymerase chain reaction (mpRT-PCR) was used to monitor viral infection. During the monitoring of tuber samples, it was found that the most common virus in almost all regions was the PVS virus at 64.5%. Moreover, most of the viruses originated in commercial farms. As a result of the analysis of leaves selected in the fields, it was found that the most common viruses in the regions were PVM at 46% and PVS at 35.3%. The work performed to monitor viral diseases in various regions of Kazakhstan will enable direct actions to maintain and improve the phytosanitary status of potatoes in Kazakhstan in the future. [ABSTRACT FROM AUTHOR]

Echo Russet is a medium- to late-maturing selection with long, large, russeted tubers. Total yields are similar to those of Russet Burbank and Ranger Russet, however Echo Russet produced significantly greater yields than Russet Norkotah. Further, Echo Russet produced significantly higher US No. 1 yields when compared to these standard varieties (6—29% more). Echo Russet has high protein, high specific gravity, light fry color, low acrylamide level, and few internal and external tuber defects. In three years of evaluations in U.S. Western Regional Potato Variety Trials, post-harvest merit scores for fresh and processing qualities were high for Echo Russet when compared to standard varieties. Echo Russet is resistant to Fusarium dry rot, Pectobacterium (syn. Erwinia) soft rot, and common scab. Echo Russet exhibits moderate resistance to Verticillium wilt, early blight, Potato virus Y (PVY), Potato leaf roll virus (PLRV), Potato mop top virus (PMTV), and corky ring spot. The preponderance of resistances to major diseases gives Echo Russet great potential for organic production and sustainable farming systems. [ABSTRACT FROM AUTHOR]

Potatoes are developed vegetatively from tubers, and therefore potato virus transmission is always a possibility. The potato leafroll virus (PLRV) is a highly devastating virus of the genus Polerovirus and family Luteoviridae and is regarded as the second-most destructive virus after Potato virus Y. Multiple species of aphids are responsible for the persistent and non-propagating transmission of PLRV. Due to intrinsic tuber damage (net necrosis), the yield and quality are drastically diminished. PLRV is mostly found in phloem cells and in extremely low amounts. Therefore, we have attempted to detect PLRV in both potato tuber and leaves using a highly sensitive, reliable and cheap method of one-step reverse transcription-recombinase polymerase amplification (RT-RPA). In this study, an isothermal amplification and detection approach was used for efficient results. Out of the three tested primer sets, one efficiently amplified a 153-bp product based on the coat protein gene. In the present study, there was no cross-reactivity with other potato viruses and the optimal amplification reaction time was thirty minutes. The products of RT-RPA were amplified at a temperature between 38 and 42 °C using a simple heating block/water bath. The present developed protocol of one-step RT-RPA was reported to be highly sensitive for both leaves and tuber tissues equally in comparison to the conventional reverse transcription-polymerase chain reaction (RT-PCR) method. By using template RNA extracted employing a cellular disc paper-based extraction procedure, the method was not only simplified but it detected the virus as effectively as purified total RNA. The simplified one-step RT-RPA test was proven to be successful by detecting PLRV in 129 samples of various potato cultivars (each consisting of leaves and tubers). According to our knowledge, this is the first report of a one-step RT-RPA performed using simple RNA extracted from cellular disc paper that is equally sensitive and specific for detecting PLRV in potatoes. In terms of versatility, durability and the freedom of a highly purified RNA template, the one-step RT-RPA assay exceeds the RT-PCR assay, making it an effective alternative for the certification of planting materials, breeding for virus resistance and disease monitoring. [ABSTRACT FROM AUTHOR]

Summary: We present here the first complete coding sequence of tomato mild mottle virus (TMMoV) infecting tree tomato in Kenya. A survey was conducted in three tree tomato-growing regions: Nairobi, Eastern, and Rift Valley. Leaf samples displaying mosaics, mottling, and malformation, were collected and analysed using high throughput RNA sequencing, which revealed the presence of TMMoV in the Eastern and the Rift Valley regions. Two coding sequences, MW537584 and MW537585 were assembled, and the HTS data were verified using RT-PCR and Sanger sequencing. Phylogenetic analysis revealed that both of these Kenyan isolates were highly similar to the Ethiopian isolate (NC038920) with 97 and 96% sequence identity, respectively. Samples from two farms that tested positive for TMMoV, also tested positive for potato virus Y (PVY), making it difficult to associate the symptoms observed with TMMoV, PVY, or a co-infection of both. [ABSTRACT FROM AUTHOR]

Summary: Hypersensitive response (HR)‐conferred resistance is associated with induction of programmed cell death and pathogen spread restriction in its proximity. The exact role of chloroplastic reactive oxygen species and its link with salicylic acid (SA) signaling in HR remain unexplained.To unravel this, we performed a detailed spatiotemporal analysis of chloroplast redox response in palisade mesophyll and upper epidermis to potato virus Y (PVY) infection in a resistant potato genotype and its transgenic counterpart with impaired SA accumulation and compromised resistance.Besides the cells close to the cell death zone, we detected individual cells with oxidized chloroplasts further from the cell death zone. These are rare in SA‐deficient plants, suggesting their role in signaling for resistance. We confirmed that chloroplast redox changes play important roles in signaling for resistance, as blocking chloroplast redox changes affected spatial responses at the transcriptional level.Through spatiotemporal study of stromule induction after PVY infection, we show that stromules are induced by cell death and also as a response to PVY multiplication at the front of infection. Overall induction of stromules is attenuated in SA‐deficient plants. [ABSTRACT FROM AUTHOR]

We investigated the roles of different concentrations of chemical synthetic spherical silver nanoparticles (AgNPs) in protecting pepper seedlings of the Mecca region, which were naturally and artificially infected by the pepper mild mottle virus (PMMoV). The virus shows many infection symptoms, including pepper leaf deformation with filiform leaves and severe mosaic symptoms. Our study focused on the antiviral activity of different concentrations of spherical nanoparticles in controlling PMMoV infecting pepper seedlings. PMMoV identification was confirmed via DAS-ELISA using the following antiserum: PMMoV, cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), tomato mosaic virus (ToMV), potato virus Y (PVY), and tomato spotted wilt virus (TSWV). The presence of PMMoV was confirmed using electron microscopy and reverse transcription polymerase chain reaction (RT-PCR). We evaluated the effects of exogenously applied different concentrations of AgNPs on CMV infection rate, infection severity, virus concentration, and the concentrations of photosynthetic pigments chlorophyll a, chlorophyll b, carotenoid content, phenolic compounds, and protein components in virus-infected plant cells that were treated with three different concentration of nanoparticles (200, 300, and 400 µg/L) compared to the positive and negative control. [ABSTRACT FROM AUTHOR]

Mineral oils have been used for many decades to control the transmission of plant viruses and their ensuing epidemics. Although it is not clearly defined, the mode of action of these oils has been extensively studied, and effects on the feeding behaviour and orientation of the vector or the transmission of the virus by its vector have often been put forward as possible explanations. This study examines the effect of mineral oil on the interaction between potato virus Y (PVY) and its vector, the green peach aphid Myzus persicae, with particular focus on the transmission organ. A lipophilic staining technique was used to visualize the oil inside the insect's stylets for the first time. Virus binding and localization were also examined in aphid stylets following PVY acquisition. The results indicate that the presence of mineral oil on leaves reduces the likelihood of acquiring the virus. This study verified that this reduced acquisition could be accompanied by a reduction in viral load, as measured by reverse transcription‐quantitative PCR on the stylets. The effect of the oil on virus retention inside the stylets was also measured. The mechanism by which the oil impacts virus acquisition seems to take place in the very early stages of acquisition, well before the virus attaches to the stylets. [ABSTRACT FROM AUTHOR]

Potato virus Y (PVY) is one of the most dangerous pathogens that cause serious damage to crop production. Fighting plant viral infections is crucial to limit these damages and save millions of dollars for farmers. Gene suppression of selected virus genes is one of the modern, innovative and effective approaches to block viral replication and infection. The virus, in turn, has developed its own strategy to avoid this gene suppression through mutations in the attacked genes of the virus genome. For this reason, blocking several important viral genes simultaneously led to better results in blocking viral replication. In this study, we achieved an epigenetic control of viral infection of PVY N/NTN of potato plants cultivar Agria by applying a combination of ds/siRNAs specific for two different conservative regions from the PVY genome, CI-6K2-NIa and HC-Pro. The potato plants that received the ds/siRNAs remained virus-free, suggesting that the CI-6K2-NIa and HC-Pro regions could serve as effective targets for control of PVY. [ABSTRACT FROM AUTHOR]

Bioinformatic approaches for the identification of microorganisms have evolved rapidly, but existing methods are time-consuming, complicated or expensive for massive screening of pathogens and their non-pathogenic relatives. Also, bioinformatic classifiers usually lack automatically generated performance statistics for specific databases. To address this problem, we developed Clasnip (www.clasnip. com), an easy-to-use web-based platform for the classification and similarity evaluation of closely related microorganisms at interspecies and intraspecies levels. Clasnip mainly consists of two modules: database building and sample classification. In database building, labeled nucleotide sequences are mapped to a reference sequence, and then single nucleotide polymorphisms (SNPs) statistics are generated. A probability model of SNPs and classification groups is built using Hidden Markov Models and solved using the maximum likelihood method. Database performance is estimated using three replicates of two-fold cross-validation. Sensitivity (recall), specificity (selectivity), precision, accuracy and other metrics are computed for all samples, training sets, and test sets. In sample classification, Clasnip accepts inputs of genes, short fragments, contigs and even whole genomes. It can report classification probability and a multi-locus sequence typing table for SNPs. The classification performance was tested using short sequences of 16S, 16-23S and 50S rRNA regions for 12 haplotypes of Candidatus Liberibacter solanacearum (CLso), a regulated plant pathogen associated with severe disease in economically important Apiaceous and Solanaceous crops. The program was able to classify CLso samples with even only 1-2 SNPs available, and achieved 97.2%, 98.8% and 100.0% accuracy based on 16S, 16-23S, and 50S rRNA sequences, respectively. In comparison with all existing 12 haplotypes, we proposed that to be classified as a new haplotype, given samples have at least 2 SNPs in the combined region of 16S rRNA (OA2/Lsc2) and 16-23S IGS (Lp Frag 4-1611F/Lp Frag 4-480R) regions, and 2 SNPs in the 50S rplJ/rplL (CL514F/CL514R) regions. Besides, we have included the databases for differentiating Dickeya spp., Pectobacterium spp. and Clavibacter spp. In addition to bacteria, we also tested Clasnip performance on potato virus Y (PVY). 251 PVY genomes were 100% correctly classified into seven groups (PVYC, PVYN, PVYO, PVYNTN, PVYN:O, Poha, and Chile3). In conclusion, Clasnip is a statistically sound and user-friendly bioinformatic application for microorganism classification at the intraspecies level. [ABSTRACT FROM AUTHOR]

Copyright of Ziemniak Polski is the property of Instytutem Hodowli & Aklimatyzacji Roslin - Panstwowym Instytutem Badawczym and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tobacco (Nicotiana tabacum L.) is an important industrial crop. Among the diseases causing losses in tobacco cultivation, viral ones are of particular importance due to the very low effectiveness of chemical protection allowing only for vector control. The greatest threat to tobacco cultivation in Poland and in many countries of the world is posed by potato virus Y (PVY), tomato spotted wilt virus (TSWV) and, in recent years, the increasingly frequent tobacco mosaic virus (TMV). The genetic resources studies carried out in the genus Nicotiana have shown a wide variation in species resistance, assessed biologically, serologically and molecularly, depending on the virus used and, in the case of PVY, also on the specific isolate. The results of the assessment of resistance in Nicotiana accessions presented in this paper, gathered from literature data as well as from our own research, allow us to broaden and systematise our knowledge on the sources of resistance to viral diseases. This is the only such an extensive study in this field. It provides an excellent information base for the appropriate selection of accessions for use in resistance breeding. [ABSTRACT FROM AUTHOR]

Passiflora virus Y was detected naturally infecting soybean (Glycine max) for the first time in Brazil. Here, we report the nearly complete genome sequence and molecular and biological properties of the PaVY-Br isolate. The nearly complete genome sequence is 9679 nt long and shares 84.4% nt sequence identity with a previously reported PaVY isolate from Passiflora sp. PaVY-Br induced chlorotic spots and systemic mosaic on soybean and chlorotic local lesions on yellow passion fruit (Passiflora edulis) and sesame (Sesamum indicum). The virus was successfully transmitted by Myzus persicae, indicating that this aphid vector can contribute to the spread of PaYV from passion fruit to soybean plants. Additional epidemiological research is in progress to investigate the distribution of PaVY in soybean production areas in Brazil. [ABSTRACT FROM AUTHOR]

Viruses pose a serious threat to the sustainable production of economically important crops around the world. In the past 20 years, potato virus Y (PVY) emerged as a relatively new and very serious problem in potatoes, even though it is the oldest known plant virus. Multiple strains of the virus cause various symptoms on the leaves and tubers of potatoes, resulting in yield reduction and poor-quality tubers. Consequently, it would be very interesting to learn what causes systemic PVY resistance in plants. Natural compounds such as chitosan (CHT) and phosphorus have been developed as alternatives to chemical pesticides to manage crop diseases in recent years. In the current study, potato leaves were foliar-sprayed with chitosan and phosphorus to assess their ability to induce PVY resistance. Compared to untreated plants, the findings demonstrated a significant decrease in disease severity and PVY accumulation in plants for which CHT and P were applied. Every treatment includes significantly increased growth parameters, chlorophyll content, photosynthetic characteristics, osmoprotectants (glycine betaine, proline, and soluble sugar), non-enzymatic antioxidants (glutathione, phenols, and ascorbic acid), enzymatic antioxidants (peroxidase, superoxide dismutase, lipoxygenase, glutathione reductase, catalase, β-1,3 glucanase, and ascorbate peroxidase), phytohormones (gibberellic acid, indole acetic acid, jasmonic acid, and salicylic acid), and mineral content (phosphorus, nitrogen, and potassium), compared to infected plants. However, compared to PVY infection values, CHT and P treatments showed a significant decrease in malondialdehyde, DPPH, H2O2, O2, OH, and abscisic acid levels. In addition, increased expression levels of some regulatory defense genes, including superoxide dismutase (SOD), ascorbic acid peroxidase (APX), relative pathogenesis-related 1 basic (PR-1b), and relative phenylalanine ammonia-lyase (PAL), were found in all treated plants, compared to PVY-infected plants. Conclusion: Phosphorus is the most effective treatment for alleviating virus infections. [ABSTRACT FROM AUTHOR]

For many years, potato seed lots have been tested for economically important pathogens in order to restrict their spread. Despite this, some pathogens inevitably make it into commercial fields and require management. Although knowledge about pathogen prevalence in commercial seed lots has increased over the last decade, assessment of the tuber necrotic viruses, Tobacco rattle virus and Potato mop-top virus, has been lacking. For seven years, four tubers from each seed lot in the Washington State University Seed Lot Trial were assessed for these two viruses. Tobacco rattle virus levels were negligible, but 1.76 to 5.50% of seed lots were infected with Potato mop-top virus each year. Potato mop-top virus was found in seven seed growing regions and 23 cultivars. These results are concerning, as the rate of transmission from seed to daughter tubers is largely unknown, and fields across the region are infested with Spongospora subterranea, the vector of Potato mop-top virus. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Polish germplasm collection of Nicotiana tabacum was started in the 1920s. Up to now, more than eight hundred accessions originating from different regions of the world have been gathered in the collection. It includes valuable breeding lines and obsolete cultivars, among them cytoplasmic male-sterile lines. Numerous cultivars are rich sources of features desired in tobacco breeding. Therefore, the accessions are continually characterised in terms of their various features, one of the most important of which is disease resistance. Much research is being done to explain the nature of resistance and its genetic basis. Moreover, cultivars with good agronomic characteristics are used in wide hybridisation, being recipients of resistance genes from wild species or are genetically modified with transgenes conditioning resistance. The biological diversity of cultivars also allows a proper selection of plant material for pathogen studies, while the large number of the accessions facilitates research into the conditions for long seed storage. Numerous examples of the use of Polish tobacco germplasm in research and breeding, specifically in disease resistance, have been presented in this paper. [ABSTRACT FROM AUTHOR]

Background. The harmful organisms affecting potato cause great economic damage in all areas where the crop is grown. One of the most economically important pathogens is the potato late blight (agent Phytophthora infestans Mont. (de Bary)). Also, Potato Virus Y (PVY) and potato cyst nematode (PCN) of the Ro1 pathotype, the only one that occurs in the Russian Federation, cause significant yield losses. Materials and methods. Phytopathological and molecular screening was carried out on original interspecific potato hybrids obtained in 11 crossing combinations, seven of which were studied for the first time. Hybrids resulted from crosses that involved Mexican and South American potato species as sources of late blight and PVY resistance. Field observations of late blight resistance were conducted during three seasons under high infection pressure. A part of plant material was screened in laboratory tests. PCR tests employed 9 DNA markers of genes associated with resistance to Ph. infestans, PVY and PCN of Ro1 pathotype used in our previous study. Results. In field evaluation, hybrid clones mostly expressed high, and a part of them moderate late blight resistance. Of the 6 markers of the used Rpi genes, at least two were detected in most clones, while some had 3 or 4 markers. Some clones were found to have markers of PCN resistance genes and of several genes for resistance to PVY. The cytoplasm type was determined for all plant material. Conclutions. Within a small but pedigree-diverse set of interspeсific hybrids, the markers of resistance genes to all three pests were found. A part of clones obtained by using the sources of PVY and late blight resistance which we had identified, were found to contain two or more resistance genes to these pathogens. According to the results of molecular tests, the clones were found to carry several markers of late blight and PVY resistance genes. Original interspecific potato hybrids with determined late blight resistance levels, cytoplasm type and availability of markers of genes for resistance to three pests can be used in further hybridization.

• With the development of a novel nanosystem, TDN-siR099@CPP@PDA-MS, this study is the first to deliver small compounds to plant by "spraying" method, so we would like to publicly present our results, and we believe that this technology broadens the application of RNA silencing (and other compounds) in plant disease management. • Attached, please carefully evaluate our scheme figure as below. • In the past, my research group published a highly cited paper in Cell Host&Microbe on the incorporation of host metabolizing enzymes (GAPDH) into the viral replicase complex by TBSV, a plus-strained RNA virus. Through in-depth mechanistic studies, we found that TBSV co-opts the RNA binding function of a metabolic protein, helping covert the host cell into a viral factory. • Similarly, the development of a nano-deliver system in a "spraying" approach for plant disease management in this study should be another sign of a new strategy for plant antiviral control (large area in the field). At the present time, the control of plant viral diseases is primarily achieved through the use of traditional pesticides. However, the tendency of RNA viruses to mutate and develop resistance to pesticides represents a significant challenge. The development of nanoscale strategies based on RNA interference (RNAi) represents a rapidly evolving approach to sustainable plant disease control. In this study, an siRNA was screened that effectively targets the 70-kDa heat shock protein (HSP70), which is closely associated with plant virus infection and replication. Additionally, a novel nanosystem for hierarchical delivery of siRNA was developed. This consisted of the cellular shuttle peptide (CPP)-modified tetrahedral DNA nanoparticles (TDN) as the core and polydopamine-hybridized mesoporous silica nanoparticles (PDA-MSN) as the shell. This was named TDN-siR099@CPP@PDA-MSNs. The results demonstrated that upon entering the leaf tissue through the stomata, TDN-siR099@CPP@PDA-MSNs encountered a weak acidic environment, prompting the PDA-MSN to release TDN-siR099@CPP. This resulted in the intercellular shuttling of TDN-siR099@CPP. The nanoscale dimensions of TDN-siR099@CPP facilitate facile displacement, while the intrinsic properties of CPP enhance the efficacy of long-distance siR099 intercellular shuttling. In this nanosystem, we also demonstrated that PDA-MSN retarded the susceptible degradation of siRNA in vitro and responded to the acidic release of the drug, which improve the utilization efficiency of siRNA in terms of both improving the delivery efficiency and delaying the degradation. It effectively down-regulated 56.2% of HSP70 protein and inhibited the infection of tobacco mosaic virus (TMV) and potato Y virus (PVY) by 70.2% and 41.0%, respectively. By skillfully constructing a framework for siRNA inhibition of target genes, this technology broadens the application of RNA silencing in plant disease management. [ABSTRACT FROM AUTHOR]

The external application of double-stranded RNA (dsRNA) has recently been developed as a non-transgenic approach for crop protection against pests and pathogens. This novel and emerging approach has come to prominence due to its safety and environmental benefits. It is generally assumed that the mechanism of dsRNA-mediated antivirus RNA silencing is similar to that of natural RNA interference (RNAi)-based defence against RNA-containing viruses. There is, however, no direct evidence to support this idea. Here, we provide data on the high-throughput sequencing (HTS) analysis of small non-coding RNAs (sRNA) as hallmarks of RNAi induced by infection with the RNA-containing potato virus Y (PVY) and also by exogenous application of dsRNA which corresponds to a fragment of the PVY genome. Intriguingly, in contrast to PVY-induced production of discrete 21 and 22 nt sRNA species, the externally administered PVY dsRNA fragment led to generation of a non-canonical pool of sRNAs, which were present as ladders of ~18–30 nt in length; suggestive of an unexpected sRNA biogenesis pathway. Interestingly, these non-canonical sRNAs are unable to move systemically and also do not induce transitive amplification. These findings may have significant implications for further developments in dsRNA-mediated crop protection.

Potato (Solanum tuberosum L) is affected by several viral pathogens with the most economically damaging being potato virus Y (PVY). At least nine biologically distinct variants of PVY are known to attack potato, with necrotic types named PVYNTN and PVYN-Wi being the most recent additions to the list. So far, the molecular plant-virus interactions underlying this pathogenicity are not fully understood. In this study, gas chromatography coupled with mass spectroscopy (GC–MS) was used for an untargeted investigation of the changes in leaf metabolomes of PVY-resistant cultivar Premier Russet, and a susceptible cultivar, Russet Burbank, following inoculation with three PVY strains, PVYNTN, PVYN-Wi, and PVYO. Analysis of the resulting GC–MS spectra with the online software Metaboanalyst (version 5.0) uncovered several common and strain-specific metabolites that are induced by PVY inoculation. In Premier Russet, the major overlap in differential accumulation was found between PVYN-Wi and PVYO. However, the 14 significant pathways occurred solely due to PVYN-Wi. In contrast, the main overlap in differential metabolite profiles and pathways in Russet Burbank was between PVYNTN and PVYO. Overall, limited overlap was observed between PVYNTN and PVYN-Wi. As a result, PVYN-Wi-induced necrosis may be mechanistically distinguishable from that of PVYNTN. Furthermore, 10 common and seven cultivar-specific metabolites as potential indicators of PVY infection and susceptibility/resistance were identified by using PLS-DA and ANOVA. In Russet Burbank, glucose-6-phosphate and fructose-6-phosphate were particularly affected by strain–time interaction. This highlights the relevance of the regulation of carbohydrate metabolism for defense against PVY. Some strain- and cultivar-dependent metabolite changes were also observed, reflecting the known genetic resistance–susceptibility dichotomy between the two cultivars. Consequently, engineering broad-spectrum resistance may be the most effective breeding strategy for managing these necrotic strains of PVY.

Potato virus Y (Potyviridae, PVY) is a plant virus that poses a significant threat to potato producers on a global basis. The pathogen has disrupted seed potato supplies and negatively impacted yield and quality of commercial potato crops. The potato industry currently manages PVY infection levels via insecticide applications, regional seed certification programs that rely on field scouting to visually assess individual plants for infection status, and destructive and costly tissue sampling coupled with laboratory assays. Despite these efforts, PVY continues to confound potato industry stakeholders resulting in economic harm. Remote sensing and machine learning provide for the development of new tools to more accurately detect and spatially quantify PVY-infected plants versus the current state of the art. However, there is a need to understand how the occurrence of many different potato varieties impact the dynamics of developing models to detect potato plants impacted with PVY and their potential effectiveness. This study evaluates classification modelling outcomes using spectral datasets collected in different temporal and spatial environments (greenhouse and a production field) on multiple potato varieties consisting of labelled instances of plants infected with PVY and those not infected with the virus. A modelling framework was developed to support iterative modelling runs using artificial neural network (ANN) architectures configured as binary classifiers to develop sample populations to support statistical analysis on model performance using specific spectral subsets. When using spectral data to detect PVY-infected plants, ANN models achieved the highest mean accuracy of 0.894 on a single variety. Conversely, the same ANN model architecture only achieved a mean accuracy of 0.575 on a spectral data set representing 29 potato breeding lines. Additionally, statistical analysis indicates spectral regions including the red edge, near infrared and shortwave infrared contain more important spectral features for the ANN classifier introduced in this research.

Potato, the world's most popular crop is reported to provide a food source for nearly a billion people. It is prone to a number of biotic stressors that affect yield and quality, out of which Potato Virus Y (PVY) occupies the top position. PVY can be transmitted mechanically and by sap-feeding aphid vectors. The application of insecticide causes an increase in the resistant vector population along with detrimental effects on the environment; genetic resistance and vector-virus control are the two core components for controlling the deadly PVY. Using transcriptomic tools together with differential gene expression and gene discovery, several loci and genes associated with PVY resistance have been widely identified. To combat this virus we must increase our understanding on the molecular response of the PVY-potato plant-aphid interaction and knowledge of genome organization, as well as the function of PVY encoded proteins, genetic diversity, the molecular aspects of PVY transmission by aphids, and transcriptome profiling of PVY infected potato cultivars. Techniques such as molecular and bioinformatics tools can identify and monitor virus transmission. Several studies have been conducted to understand the molecular basis of PVY resistance/susceptibility interactions and their impact on PVY epidemiology by studying the interrelationship between the virus, its vector, and the host plant. This review presents current knowledge of PVY transmission, epidemiology, genome organization, molecular to bioinformatics responses, and its effective management. [ABSTRACT FROM AUTHOR]

Plants of Physalis peruviana showing typical virus symptoms of mosaic and leaf distortion were found in the municipalities of Piracicaba city, São Paulo state, and Senador Amaral, Minas Gerais state, Brazil. Based on molecular assays and nucleotide sequencing, two potyviruses, potato virus Y (PVY) and pepper yellow mosaic virus (PepYMV) were identified in mixed infection with the sobemovirus physalis rugose mosaic virus (PhyRMV) in symptomatic plants collected in Piracicaba. Collected plants in Senador Amaral showed mixed infection with PepYMV and PhyRMV. To our knowledge, this is the first report of these potyviruses naturally infecting P. peruviana in Brazil. [ABSTRACT FROM AUTHOR]

Proteins of the alkylation B (AlkB) superfamily show RNA demethylase activity removing methyl adducts from N6‐methyladenosine (m6A). m6A is a reversible epigenetic mark of RNA that regulates human virus replication but has unclear roles in plant virus infection. We focused on Potyvirus—the largest genus of plant RNA viruses—and report here the identification of AlkB domains within P1 of endive necrotic mosaic virus (ENMV) and an additional virus of a putative novel species within Potyvirus. We show that Nicotiana benthamiana m6A levels are reduced by infection of plum pox virus (PPV) and potato virus Y (PVY). The two potyviruses lack AlkB and the results suggest a general involvement of RNA methylation in potyvirus infection and evolution. Methylated RNA immunoprecipitation sequencing of virus‐infected samples showed that m6A peaks are enriched in plant transcript 3′ untranslated regions and in discrete internal and 3′ terminal regions of PPV and PVY genomes. Down‐regulation of N. benthamiana AlkB homologues of the plant‐specific ALKBH9 clade caused a significant decrease in PPV and PVY accumulation. In summary, our study provides evolutionary and experimental evidence that supports the m6A implication and the proviral roles of AlkB homologues in Potyvirus infection. [ABSTRACT FROM AUTHOR]

Potato virus Y (PVY) is one of the most harmful phytopathogens. It causes big problems for potatoes and other important crops around the world. Nanoclays have been extensively studied for various biomedical applications. However, reports on their interactions with phytopathogens, particularly viral infections, are still limited. In this study, the protective activity of Egyptian nanoclay (CE) and standard nanoclay (CS) against PVY was evaluated on potato (Solanum tuberosum L.) plants. Their physicochemical and morphological properties were examined with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and energy dispersive spectrometer (EDS). SEM and TEM analyses revealed that CE has a spherical and hexagonal structure ranging from 20 to 80 nm in size, while CS has boulder-like and tubular structures of about 320 nm in size. FTIR and EDS showed that both nanoclay types have different functional groups and contain many vital plant nutrients that are necessary for every stage and process of the plant, including development, productivity, and metabolism. Under greenhouse conditions, a 1% nanoclay foliar application enhanced potato growth, reduced disease symptoms, and reduced PVY accumulation levels compared with non-treated plants. Significant increases in levels of antioxidant enzymes (PPO and POX) and considerable decreases in oxidative stress markers (MDA and H2O2) were also reported. Moreover, a significant increase in the transcriptional levels of defense-related genes (PAL-1, PR-5, and CHI-2) was observed. All experiment and analysis results indicate that the CE type is more effective than the CS type against PVY infection. Based on these results, the foliar applications of nanoclay could be used to manage plant viral infections in a way that is both effective and environmentally friendly. To our knowledge, this is the first report of the antiviral activity of the foliar application of nanoclay against PVY infection. [ABSTRACT FROM AUTHOR]

Simple Summary: Klebsiella oxytoca, as a type of plant growth-promoting rhizobacteria (PGPR), was studied with regards to promoting plant growth and inducing plant systemic resistance against Potato Virus Y (PVY). The results of greenhouse experiments with tobacco and potato plants demonstrated that treatments with the Klebsiella oxytoca and biochar significantly enhanced the growth, while clearly lowering the disease severity and concentration of PVY. An RT-PCR analysis of the defense genes in the tobacco and potato treated with the Klebsiella oxytoca and biochar revealed an association with enhancing the systemic resistance of tobacco and potato to PVY. Klebsiella oxytoca and biochar may be considered valuable options to control PVY in potato and other Solanaceae crops. Potato Virus Y (PVY) is a serious potato disease that may significantly decrease potato production. To suppress potato virus infection, several measures have been undertaken. The utilization of plant growth-promoting rhizobacteria is one of these methods. Biochar soil treatment is believed to provide plants with a number of advantages, including increased plant growth and the development of systemic resistance to a variety of plant diseases. The goal of this research was to see whether adding biochar and Klebsiella oxytoca to the soil might cause PVY resistance and enhance the involved mechanisms in PVY resistance. Potato and tobacco seedlings treated with Klebsiella oxytoca and biochar exhibited the same impact of significant symptom reduction, with complete negative ELISA findings, supporting the antiviral activity of K. oxytoca and biochar. Furthermore, owing to the connection between the ISR implicated substrates, significant amounts of polyphenol oxidase, catalase, and superoxide dismutase were observed in treated plants, with the same behavior as defense genes expression levels. It may be a step forward in the development of biochar and K. oxytoca as potential environmentally friendly disease control strategies against PVY. [ABSTRACT FROM AUTHOR]

Myzus persicae (Sulzer) is an important agricultural pest worldwide causing major economic losses due to its ability to transmit over 100 viruses including Potato virus Y (PVY). Myzus persicae shows considerable variation with respect to performance on its host plants. The objective of this study was to use a survival experiment, behavioural observations, including observations of probing and feeding behaviour obtained using the electrical penetration graph (EPG) technique, and a PVY acquisition experiment to determine whether or not potato was still the more suitable host for M. persicae originating on potato and reared on a novel host, table beet, for over 15 years. In a survival experiment, the pre-reproductive period was significantly longer while adult survival and whole longevity were significantly lower for M. persicae reared on beet fed beet leaves compared to M. persicae reared on potato fed potato leaves. The number of progenies produced and fecundity were both significantly reduced (90 and 85%, respectively) for M. persicae reared on beet fed beet leaves. Ethological observations and EPG assessment of M. persicae behaviour reared on beet placed on beet leaves showed significantly impaired behavioural responses compared to M. persicae reared on potato placed on potato leaves. The rate of PVY acquisition was the same for M. persicae reared on beet and on potato. These results indicate that after 15 years on table beet, M. persicae still performs better on its original host, potato, and appears to be a specialized potato-adapted genotype. [ABSTRACT FROM AUTHOR]

Pepper (Capsicum annuum L.) plants produce berry fruits that are used as spices. Here, we examined the viromes of 15 pepper cultivars through RNA sequencing. We obtained 1,325 virus-associated contigs derived from 8 virus species. Bean broad wilt virus 2 (BBWV2) and cucumber mosaic virus (CMV) were identified as the major viruses infecting pepper plants, followed by potato virus Y, bell pepper endornavirus, and hot pepper endornavirus. The proportion of viral reads in each transcriptome ranged from 0.04% to 24.5%. BBWV2 was the dominant virus in seven cultivars, whereas CMV was dominant in five cultivars. All the bell pepper cultivars showed severe viral disease symptoms, whereas the commercially developed hot pepper cultivars were asymptomatic or had mild symptoms. In addition, 111 complete viral segments were obtained from 7 viruses. Based on the obtained viral genomes, the genetic relationship between the identified viruses and quasispecies of BBWV2 and CMV in each pepper plant was determined. Newly designed primers for nine viruses confirmed the results of RNA sequencing. Taken together, this study, for the first time, provides a comprehensive overview of viromes in 15 major pepper cultivars through RNA sequencing. [ABSTRACT FROM AUTHOR]

Aphid transmitted viruses are the most significant constraint for quality seed potato production. Potato virus Y and Potato leaf roll virus are the most important aphid transmitted viruses in potato, which can be transmitted by a large number of aphid species. In order to determine the species composition of aphids infesting potato crops and to determine their viruliferous nature, aphid samples were collected from all the potatoes growing zones in India. Fourteen distinct aphid species were identified from 541 samples using morphological and molecular characterization. The identified species include Aphis craccivora, A. gossypii, A. fabae, A. spiraecola, Aulacorthum solani, Macrosiphum euphorbiae, Rhopalosiphum rufiabdominale, and Myzus persicae among the colonizing species and A. nerii, R. padi, R. maidis, Hyadaphis coriandri, Brevicoryne brassicae, and Lipaphis erysimi among the non-colonizing species. M. persicae and A. gossypii were the most abundant and most widespread species on potato in the country. Based on whole body testing of aphid samples through RT-PCR, M. persicae, A. gossypii, A. solani, and M. euphorbiae were found positive for PVY while M. persicae and A. gossypii tested positive for PLRV, which could potentially transmit the respective viruses in potato crops. The current study revealed that aphid species other than M. persicae could be important in determining the virus incidence in seed crops in the country. Therefore, management decisions should include such information to maintain the health standard of seed stocks. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum) is a valuable crop worldwide and is widely infected with the potyvirus potato virus Y (PVY), which causes serious yield loss. Viral infection depends on host elements and the eukaryotic translation initiation factor 4E (eIF4E) is essential in the potyvirus life cycle. To generate potyvirus resistance, the tomato SleIF4E1 and SleIF4E2 genes were disrupted and knockout mutants (sleif4e1, sleif4e2 and double mutant sleif4e1/e2) were generated using CRISPR/Cas9 technology. Mutant plants were evaluated for resistance to PVY following mechanical inoculation. The sleif4e1 and sleif4e1/e2 mutants did not display the PVY related symptoms as observed in wild type and sleif4e2 plants. During the first 21 days post infection, PVY coat protein accumulation was significantly lower in the sleif4e1, sleif4e1/e2 mutants than in the wild type and sleif4e2 plants and was undetectable 32 days post infection. However, PVY RNA accumulation was observed in sleif4e1 and sleif4e1/e2 virus resistant plants, reflecting that resistance is associated with impaired translation and not viral RNA accumulation. Interestingly, two amino acid changes, 119H/Y and 123S/N, were observed in the viral-encoded VPg gene in sleif4e1/e2 double mutant plants infected with PVY, indicating selection pressure on viral genes during replication. None of the mutant plants showed resistance to any virus but PVY when challenged with eggplant mild leaf mottle virus, cucumber mosaic virus, pepino mosaic virus and tomato brown rugose fruit virus. Thus, it was demonstrated that SleIF4E-mediated resistance is specific to PVY. [ABSTRACT FROM AUTHOR]

Wild plant species play an important role in plant virus epidemiology, mainly by harbouring viruses pathogenic to cultivated plant species. The genus Solanum includes important crop species as well as some highly abundant and widely distributed wild plant species. The aim of the present study was to profile the viromes of 11 wild Solanum spp. found in five provinces of South Africa. Metatranscriptomic analysis of pooled RNA samples from each of the Solanum spp. detected viruses belonging to 13–19 families. Reverse transcription PCR confirmed the detection of potato virus Y (PVY), potato leaf roll virus (PLRV), tomato torrado virus (ToTV) and tomato chlorosis virus (ToCV) for the first time in some of the Solanum spp. studied. Phylogenetic analyses indicated that the PVY and PLRV strains from the wild Solanum spp. were divergent from those reported in cultivated crops, while there was limited divergence among ToTV and ToCV isolates. Viruses detected for the first time in South Africa included tobacco mild green mosaic virus, tomato matilda virus, a pepper enamovirus from Rwanda and a cytorhabdovirus from potato in Kenya. Potentially novel viruses were also detected in S. lichtensteinii, S. mauritianum and S. viarum. This study demonstrates the role of Solanum spp. in harbouring viruses pathogenic to solanaceous crops, and in the emergence of new virus strains. It may therefore inform strategies for virus disease management by control of wild solanums that harbour viruses pathogenic to important Solanum crops. [ABSTRACT FROM AUTHOR]

A viral chimera in which the P1-HCPro bi-cistron of a plum pox virus construct (PPV-GFP) was replaced by that of potato virus Y (PVY) spread slowly systemically in Nicotiana benthamiana plants and accumulated to levels that were 5−10% those of parental PPV-GFP. We tested whether consecutive mechanical passages could increase its virulence, and found that after several passages, chimera titers rose and symptoms increased. We sequenced over half the genome of passaged chimera lineages infecting two plants. The regions sequenced were 5′NCR-P1-HCPro-P3; Vpg/NIa; GFP-CP, because of being potential sites for mutations/deletions leading to adaptation. We found few substitutions, all non-synonymous: two in one chimera (nt 2053 HCPro, and 5733 Vpg/NIa), and three in the other (2359 HCPro, 5729 Vpg/NIa, 9466 CP). HCPro substitutions 2053 AUU(Ile)→ACU(Thr), and 2359 CUG(Leu)→CGG(Arg) occurred at positions where single nucleotide polymorphisms were observed in NGS libraries of sRNA reads from agroinfiltrated plants (generation 1). Remarkably, position 2053 was the only one in the sequenced protein-encoding genome in which polymorphisms were common to the four libraries, suggesting that selective pressure existed to alter that specific nucleotide, previous to any passage. Mutations 5729 and 5733 in the Vpg by contrast did not correlate with polymorphisms in generation 1 libraries. Reverse genetics showed that substitution 2053 alone increased several-fold viral local accumulation, speed of systemic spread, and systemic titers. [ABSTRACT FROM AUTHOR]

Potato virus Y (PVY, Potyviridae) is among the most important viral pathogens of potato. The potato resistance gene Ny tbr confers hypersensitive resistance to the ordinary strain of PVY (PVY O ), but not the necrotic strain (PVY N ). Here, we unveil that residue 247 of PVY helper component proteinase (HCPro) acts as a central player controlling Ny tbr strain-specific activation. We found that substituting the serine at 247 in the HCPro of PVY O (HCPro O ) with an alanine as in PVY N HCPro (HCPro N ) disrupts Ny tbr recognition. Conversely, an HCPro N mutant carrying a serine at position 247 triggers defence. Moreover, we demonstrate that plant defences are induced against HCPro O mutants with a phosphomimetic or another phosphorylatable residue at 247, but not with a phosphoablative residue, suggesting that phosphorylation could modulate Ny tbr resistance. Extending beyond PVY, we establish that the same response elicited by the PVY O HCPro is also induced by HCPro proteins from other members of the Potyviridae family that have a serine at position 247, but not by those with an alanine. Together, our results provide further insights in the strain-specific PVY resistance in potato and infer a broad-spectrum detection mechanism of plant potyvirus effectors contingent on a single amino acid residue., (© 2024 The Author(s). Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)

In this study, the impact of culture media filtrate of QD3 actinobacterial isolate on two potato cultivars, Spunta and Diamond, infected with potato virus Y (PVY) was investigated. Various parameters, including infection percentage, PVY virus infectivity, disease severity scoring, PVY optical density, photosynthetic and defense-related biochemical markers, enzymatic profiling, phenolic compounds, proline content, salicylic acid levels, and growth and yield parameters, were assessed to elucidate the potential of the QD3 actinobacterial isolate culture filtrate in mitigating PVY-induced damage. The physiological and biochemical characteristics of the QD3 actinobacterial isolate, including its salinity tolerance, pH preferences, and metabolic traits, were investigated. Molecular identification via 16S rRNA gene sequencing confirmed its classification as Streptomyces fradiae QD3, and it was deposited in GenBank with the gene accession number MN160630. Distinct responses between Spunta and Diamond cultivars, with Spunta displaying greater resistance to PVY infection. Notably, pre-infection foliar application of the QD3 filtrate significantly reduced disease symptoms and virus infection in both cultivars. For post-PVY infection, the QD3 filtrate effectively mitigated disease severity and the PVY optical density. Furthermore, the QD3 filtrate positively influenced photosynthetic pigments, enzymatic antioxidant activities, and key biochemical components associated with plant defense mechanisms. Gas chromatography‒mass spectrometry (GC‒MS) analysis revealed palmitic acid (hexadecanoic acid, methyl ester) and oleic acid (9-octadecanoic acid, methyl ester) as the most prominent compounds, with retention times of 23.23 min and 26.41 min, representing 53.27% and 23.25%, respectively, of the total peak area as primary unsaturated fatty acids and demonstrating antiviral effects against plant viruses. Cytotoxicity assays on normal human skin fibroblasts (HSFs) revealed the safety of QD3 metabolites, with low discernible toxicity at high concentrations, reinforcing their potential as safe and effective interventions. The phytotoxicity results indicate that all the seeds presented high germination rates of approximately 95-98%, suggesting that the treatment conditions had no phytotoxic effect on the Brassica oleracea (broccoli) seeds, Lactuca sativa (lettuce) seeds, and Eruca sativa (arugula or rocket) seeds. Overall, the results of this study suggest that the S. fradiae filtrate has promising anti-PVY properties, influencing various physiological, biochemical, and molecular aspects in potato cultivars. These findings provide valuable insights into potential strategies for managing PVY infections in potato crops, emphasizing the importance of Streptomyces-derived interventions in enhancing plant health and crop protection., (© 2024. The Author(s).)

Background: Potato virus Y (PVY) is a prominent representative of plant viruses. It can inflict severe damage upon Solanaceae plants, leading to global dissemination and substantial economic losses. To discover new antiviral agents, a class of planar chiral thiourea molecules through the key step of N-heterocyclic carbene-catalyzed nitrile formation reaction was synthesized with excellent optical purities for antiviral evaluations against plant virus PVY., Results: The absolute configurations of the planar chiral compounds exhibited obvious distinctions in the anti-PVY activities. Notability, compound (S)-4u exhibited remarkable curative activities against PVY, with a half maximal effective concentration (EC 50 ) of 349.3 μg mL -1 , which was lower than that of the ningnanmycin (NNM) (EC 50  = 400.8 μg mL -1 ). Additionally, The EC 50 value for the protective effects of (S)-4u was 146.2 μg mL -1 , which was superior to that of NNM (276.4 μg mL -1 ). Furthermore, the mechanism-of-action of enantiomers of planar chiral compound 4u was investigated through molecular docking, defensive enzyme activity tests and chlorophyll content tests., Conclusion: Biological mechanism studies have demonstrated that the configuration of planar chiral target compounds plays a crucial role in the molecular interaction with PVY-CP, enhancing the activity of defense enzymes and affecting chlorophyll content. The current study has provided significant insights into the roles played by planar chiralities in plant protection against viruses. This paves the way for the development of novel green pesticides bearing planar chiralities with excellent optical purities. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Tobacco is an important commercial crop and a rich source of alkaloids for pharmaceutical and agricultural applications. However, its yield can be reduced by up to 70% due to virus infections, especially by a potyvirus Potato virus Y (PVY). The replication of PVY relies on host factors, and eukaryotic translation initiation factor 4Es (eIF4Es) have already been identified as recessive resistance genes against potyviruses in many plant species. To investigate the molecular basis of PVY resistance in the widely cultivated allotetraploid tobacco variety K326, we developed a dual guide RNA CRISPR/Cas9 system for combinatorial gene editing of two clades, eIF4E1 (eIF4E1-S and eIF4E1-T) and eIF4E2 (eIF4E2-S and eIF4E2-T) in the eIF4E gene family comprising six members in tobacco. We screened for CRISPR/Cas9-induced mutations by heteroduplex analysis and Sanger sequencing, and monitored PVYO accumulation in virus challenged regenerated plants by DAS-ELISA both in T0 and T1 generations. We found that all T0 lines carrying targeted mutations in the eIF4E1-S gene displayed enhanced resistance to PVYO confirming previous reports. More importantly, our combinatorial approach revealed that eIF4E1-S is necessary but not sufficient for complete PVY resistance. Only the quadruple mutants harboring loss-of-function mutations in eIF4E1-S, eIF4E1-T, eIF4E2-S and eIF4E2-T showed heritable high-level resistance to PVYO in tobacco. Our work highlights the importance of understanding host factor redundancy in virus replication and provides a roadmap to generate virus resistance by combinatorial CRISPR/Cas9-mediated editing in non-model crop plants with complex genomes. [ABSTRACT FROM AUTHOR]

The Potato virus Y (PVY) is responsible for huge economic losses for the potato industry worldwide and is the fifth most consequential plant virus globally. The main strategies for virus control are to limit aphid vectors, produce virus-free seed potatoes, and breed virus-resistant varieties. The breeding of PVY-resistant varieties is the safest and most effective method in terms of cost and environmental protection. Rychc, a gene that confers extreme resistance to PVY, is from S. chacoense, which is a wild diploid potato species that is widely used in many PVY-resistant breeding projects. In this study, Rychc was fine mapped and successfully cloned from S. chacoense accession 40-3. We demonstrated that Rychc encodes a TIR-NLR protein by stably transforming a diploid susceptible cultivar named AC142 and a tetraploid potato variety named E3. The Rychc conferred extreme resistance to PVYO, PVYN:O and PVYNTN in both of the genotypes. To investigate the genetic events occurring during the evolution of the Rychc locus, we sequenced 160 Rychc homologs from 13 S. chacoense genotypes. Based on the pattern of sequence identities, 160 Rychc homologs were divided into 11 families. In Family 11 including Rychc, we found evidence for Type I evolutionary patterns with frequent sequence exchanges, obscured orthologous relationships and high non-synonymous to synonymous substitutions (Ka/Ks), which is consistent with rapid diversification and positive selection in response to rapid changes in the PVY genomes. Furthermore, a functional marker named MG64-17 was developed in this study that indicates the phenotype with 100% accuracy and, therefore, can be used for marker-assisted selection in breeding programs that use S. chacoense as a breeding resource. [ABSTRACT FROM AUTHOR]

Summary: Knowledge of the immune mechanisms responsible for viral recognition is critical for understanding durable disease resistance and successful crop protection. We determined how potato virus Y (PVY) coat protein (CP) is recognised by Rysto, a TNL immune receptor.We applied structural modelling, site‐directed mutagenesis, transient overexpression, co‐immunoprecipitation, infection assays and physiological cell death marker measurements to investigate the mechanism of Rysto–CP interaction.Rysto associates directly with PVY CP in planta that is conditioned by the presence of a CP central 149 amino acids domain. Each deletion that affects the CP core region impairs the ability of Rysto to trigger defence. Point mutations in the amino acid residues Ser125, Arg157, and Asp201 of the conserved RNA‐binding pocket of potyviral CP reduce or abolish Rysto binding and Rysto‐dependent responses, demonstrating that appropriate folding of the CP core is crucial for Rysto‐mediated recognition.Rysto recognises the CPs of at least 10 crop‐damaging viruses that share a similar core region. It confers immunity to plum pox virus and turnip mosaic virus in both Solanaceae and Brassicaceae systems, demonstrating potential utility in engineering virus resistance in various crops. Our findings shed new light on how R proteins detect different viruses by sensing conserved structural patterns. [ABSTRACT FROM AUTHOR]

Aged plants are more difficult to infect than young plantlets. This modification of susceptibility is described as mature plant resistance (MPR). For potato virus Y (PVY), MPR is known to lead to low infection rates of plants inoculated at the postflowering stage and a decrease in the number of infected daughter tubers. However, the impact of inoculation date on the capacity of PVY to accumulate in daughter tubers has not been studied so far. Field and greenhouse experiments were carried out to better understand PVY epidemiology and to help potato growers to evaluate consequences of early/late infections on the quality of their crops. In field trials, potato plants (cv. Bintje) were covered by insectproof nets from planting to harvest except for a 14‐day period to expose plants to natural PVY infections. Under controlled conditions, potato plants were mechanically inoculated with PVY at different dates from preflowering stages (early inoculations) to postflowering stage (late inoculations). At harvest, daughter tubers were individually collected and analysed to define proportions and viral load of infected tubers according to the time between virus inoculation and harvest. Our results showed that although the age of plants at the time of inoculation can modify their susceptibility to PVY infection, in return, early and late PVY inoculations lead to similar rates of infected tubers at the plant scale and equivalent viral accumulation in infected tubers. All together, these data revealed that both early/late infections are high risks for the sanitary quality of potato tubers. [ABSTRACT FROM AUTHOR]

【Objective】 The study aimed to understand the harm of main potato viruses to potato production in some areas of Qinghai province, to clarify the main virus types and PVY strain types in some potato production areas of Qinghai province, and to provide a scientific basis for the prevention and control of potato virus diseases and variety selection. 【Method】181 samples of suspected potato virus disease collected from Datong county and Huzhu county of Qinghai province were used for virus species detection and Y virus strain type analysis using DAS-ELISA and RT-PCR combined with bioinformatics analysis methods. 【Result】Among the 181 samples, the detection rates of PVY, PVS, PVM and PLRV viruses were 17.68%, 19.34%, 4.42% and 4.42%, respectively. Among them, PVY alone had the highest infection rate of 14.92%, followed by PVS at 12.71%. PVX, PVA and AMV viruses were not detected in the samples. In the compound infection, two kinds of viruses are the main ones, among which PVS+PVM, PVY+PVS and PVS+PLRV were more common. DAS-ELISA detection of PVY alone infection combined with RT-PCR mixed detection to obtain 20 PVY positive samples, the serological analysis of potato Y virus strains on them showed that the potato Y virus strains in some areas of Qinghai province were PVYO+C serotypes. Among them, 19 strains were positive for PVYO+C serotypes, accounting for 95%, and 1 strain was positive for PVYN and PVYC serotypes, accounting for 5%. In order to further clarify the PVY sub-strains, the gene sequences of the 19 PVY isolates obtained were analyzed according to the serological test results, and it was found that the nucleotide identity rate of PVY virus was 97.0%-100%, and the amino acid identity rate was 95.8%-100%, and no recombination sites were found, and the population genes were relatively stable. The phylogenetic analysis of PVY isolates showed that 16 PVY isolates were closely related to PVYN:O lines, and 3 PVY isolates were related to PVYNTN-NW lines. The relationship was relatively close, and the strains of potato Y virus in some areas of Qinghai province were mainly PVYN:O and PVYNTN-NW strains, which were consistent with the serological test results. 【Conclusion】 The main potato virus species in some areas of Qinghai province were PVY, PVS, PVM and PLRV, PVY and PVS were the main epidemic species of potato virus in Qinghai area, among which the Y virus strains were mainly PVYN:O and PVYNTN-NW strains, with high homology, and the PVY population genes were relatively stable. [ABSTRACT FROM AUTHOR]

Research on aquatic plant viruses is lagging behind that of their terrestrial counterparts. To address this knowledge gap, here we identified viruses associated with freshwater macrophytes, a taxonomically diverse group of aquatic phototrophs that are visible with the naked eye. We surveyed pooled macrophyte samples collected at four spring sites in Florida, USA through next generation sequencing of RNA extracted from purified viral particles. Sequencing efforts resulted in the detection of 156 freshwater macrophyte associated (FMA) viral contigs, 37 of which approximate complete genomes or segments. FMA viral contigs represent putative members from all five major phyla of the RNA viral kingdom Orthornavirae. Similar to viral types found in land plants, viral sequences identified in macrophytes were dominated by positive-sense RNA viruses. Over half of the FMA viral contigs were most similar to viruses reported from diverse hosts in aquatic environments, including phototrophs, invertebrates, and fungi. The detection of FMA viruses from orders dominated by plant viruses, namely Patatavirales and Tymovirales, indicate that members of these orders may thrive in aquatic hosts. PCR assays confirmed the presence of putative FMA plant viruses in asymptomatic vascular plants, indicating that viruses with persistent lifestyles are widespread in macrophytes. The detection of potato virus Y and oat blue dwarf virus in submerged macrophytes suggests that terrestrial plant viruses infect underwater plants and highlights a potential terrestrial-freshwater plant virus continuum. Defining the virome of unexplored macrophytes will improve our understanding of virus evolution in terrestrial and aquatic primary producers and reveal the potential ecological impacts of viral infection in macrophytes. [ABSTRACT FROM AUTHOR]

Tissue culture methods enable virus elimination from vegetatively propagated crop plants but cannot prevent new infections. Here we used a tissue culture transgenic approach for curing field cultivars of Solanum tuberosum through the stimulation of RNA interference (RNAi)-based antiviral defenses. Expression cassettes carrying inverted repeats of potato virus S (PVS, genus Carlavirus) movement or coat protein sequences were used for the transformation of potato cultivars naturally infected with PVS and/or a related carlavirus potato virus M (PVM), without or with potato virus Y (PVY, genus Potyvirus). A high proportion of transformants PCR-positive for transgenes were cured from both carlaviruses and PVY. After 3-year field trials, 22 transgenic lines representing seven cultivars remained free of any virus or became infected only with PVY. Vegetative progenies of the transgenic lines of cultivar Zeren (initially coinfected with PVS, PVM, and PVY), sampled after in vitro propagation or field trials, and other field cultivars accumulated transgene-derived 21, 22, and 24 nt small interfering (si)RNAs almost exclusively from the PVS inverted repeats. Additionally, some field progenies accumulated 21–22 nt siRNAs from the entire PVY genome, confirming PVY infection. Taken together, transgenic RNAi is effective for virus elimination from naturally infected potato cultivars and their sequence-specific immunization against new infections. [ABSTRACT FROM AUTHOR]

In this work we developed and exploited a spray-induced gene silencing (SIGS)-based approach to deliver double-stranded RNA (dsRNA), which was found to protect potato against potato virus Y (PVY) infection. Given that dsRNA can act as a defence-inducing signal that can trigger sequence-specific RNA interference (RNAi) and non-specific pattern-triggered immunity (PTI), we suspected that these two pathways may be invoked via exogeneous application of dsRNA, which may account for the alterations in PVY susceptibility in dsRNA-treated potato plants. Therefore, we tested the impact of exogenously applied PVY-derived dsRNA on both these layers of defence (RNAi and PTI) and explored its effect on accumulation of a homologous virus (PVY) and an unrelated virus (potato virus X, PVX). Here, we show that application of PVY dsRNA in potato plants induced accumulation of both small interfering RNAs (siRNAs), a hallmark of RNAi, and some PTI-related gene transcripts such as WRKY29 (WRKY transcription factor 29; molecular marker of PTI), RbohD (respiratory burst oxidase homolog D), EDS5 (enhanced disease susceptibility 5), SERK3 (somatic embryogenesis receptor kinase 3) encoding brassinosteroid-insensitive 1-associated receptor kinase 1 (BAK1), and PR-1b (pathogenesis-related gene 1b). With respect to virus infections, PVY dsRNA suppressed only PVY replication but did not exhibit any effect on PVX infection in spite of the induction of PTI-like effects in the presence of PVX. Given that RNAi-mediated antiviral immunity acts as the major virus resistance mechanism in plants, it can be suggested that dsRNA-based PTI alone may not be strong enough to suppress virus infection. In addition to RNAi- and PTI-inducing activities, we also showed that PVY-specific dsRNA is able to upregulate production of a key enzyme involved in poly(ADP-ribose) metabolism, namely poly(ADP-ribose) glycohydrolase (PARG), which is regarded as a positive regulator of biotic stress responses. These findings offer insights for future development of innovative approaches which could integrate dsRNA-induced RNAi, PTI and modulation of poly(ADP-ribose) metabolism in a co-ordinated manner, to ensure a high level of crop protection. [ABSTRACT FROM AUTHOR]