Publications by authors named "Stewart Gray"

Cereal yellow dwarf virus (CYDV-RPV) encodes a P0 protein that functions as a viral suppressor of RNA silencing (VSR). The strength of silencing suppression is highly variable among CYDV-RPV isolates. In this study, comparison of the P0 sequences of CYDV-RPV isolates and mutational analysis identified a single C-terminal amino acid that influenced P0 RNA-silencing suppressor activity.

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The United States potato industry has recently experienced a strain shift; recombinant potato virus Y (PVY) strains (e.g., PVY) have emerged as the predominant strains over the long dominant ordinary strain (PVY), yet both are often found as single infections within the same field and as mixed infections within individual plants.

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Tobacco rattle virus (TRV) is an important soil-borne virus of potato that is transmitted by stubby-root nematodes. TRV causes corky ringspot, a tuber disease of economic importance to potato production. Utilizing protein-coding regions of the whole genome and a range of computational tools, the genetic diversity, and population structure of TRV isolates from several potato-growing regions (Colorado, Idaho, Indiana, Minnesota, Nebraska, North Dakota, and Washington State) in the USA were determined.

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Background: Transgender and gender nonbinary (trans/NB) individuals face many barriers to accessing health care in the United States due to systemic and clinician discrimination. Such experiences can lead to avoidance or delays in seeking care. These issues are relevant for emergency department (ED) clinicians and staff because trans/NB patients may use the ED in times of crisis.

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In recent years, several recombinant strains of potato virus Y notably PVY and PVY have displaced the ordinary strain, PVY, and emerged as the predominant strains affecting the USA potato crop. Previously we reported that recombinant strains were transmitted more efficiently than PVY when they were acquired sequentially, regardless of acquisition order. In another recent study, we showed that PVY binds preferentially to the aphid stylet over PVY when aphids feed on a mixture of PVY and PVY.

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The vast majority of plant viruses are transmitted by insect vectors, with many crucial aspects of the transmission process being mediated by key protein-protein interactions. Still, very few vector proteins interacting with viruses have been identified and functionally characterized. (PLRV) is transmitted most efficiently by , the green peach aphid, in a circulative, non-propagative manner.

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Article Synopsis
  • Single aphids are capable of acquiring and transmitting multiple strains of potato virus Y (PVY) simultaneously or one after the other.
  • Research using immuno-staining and confocal microscopy showed that these PVY strains can co-localize and dynamically interact in infected plant leaves, particularly in tobacco and potato.
  • The study challenges the previous belief of spatial separation between similar potyvirus strains, indicating that these PVY strains can coexist and interact non-antagonistically, potentially explaining the rise of new recombinant PVY strains in potatoes.
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Potato virus Y (PVY) is one of the main viruses affecting potato in Australia. However, molecular characterization of PVY isolates circulating in potato in different states of Australia has not yet been thoroughly conducted. Only nonrecombinant isolates of three biological PVY strains collected from potato were reported previously from Western Australia and one from Queensland.

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is a soilborne plasmodiophorid that causes powdery scab in potato. It also transmits potato mop-top virus (PMTV), which causes necrotic arcs (spraing) in potato tubers. Three field experiments were conducted in naturally -infested soil to investigate the effects of two chemicals, Omega 500F (fluazinam) and FOLI-R-PLUS RIDEZ (biological extract), on powdery scab, PMTV, and changes in inoculum with six different potato cultivars.

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Transmission is a crucial part of a viral life cycle and transmission mode can have an important impact on virus biology. It was demonstrated that transmission mode can influence the virulence and evolution of a virus; however, few empirical data are available to describe the direct underlying changes in virus population structure dynamics within the host. Potato virus Y (PVY) is an RNA virus and one of the most damaging pathogens of potato.

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Transgender/nonbinary (trans/NB) patients face stigma in health care settings. Health care professionals' training on trans/NB issues has historically been lacking. Interprofessional education (IPE) provides an opportunity to improve knowledge and attitudes across health care professions.

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Article Synopsis
  • The C-terminal region of the potato leafroll virus (PLRV) readthrough protein (RTP) is crucial for virus movement, tissue tropism, and symptom development, with a specific five-amino acid motif identified as vital for its function.
  • A mutant of PLRV lacking these five amino acids (Δ5aa-RTP) showed limited infection despite being able to move long distances, indicating that the motif plays a role in virus loading and unloading in plant tissues.
  • The deletion of these five amino acids altered RTP localization from the cell periphery near plasmodesmata to the cytoplasm, highlighting the importance of this motif in regulating RTP's function and supporting viral infection dynamics.
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Potato virus Y (PVY) has reemerged as a serious impediment to seed potato production, responsible for reduced yields and tuber quality, as well as the majority of seed lot rejections by certification programs due to excessive virus incidence. This has led to seed shortages, especially in cultivars highly susceptible to infection. While seed certification programs have been effective at managing many virus diseases below economic thresholds, PVY has rapidly evolved in recent decades to become a complex of strains that evade many certification and farm management practices.

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The is an agriculturally important family of viruses whose replication and transport are restricted to plant phloem. Their genomes encode for four proteins that regulate viral movement. These include two structural proteins that make up the capsid and two non-structural proteins known as P3a and P17.

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Chloroplasts play a central role in pathogen defense in plants. However, most studies explaining the relationship between pathogens and chloroplasts have focused on pathogens that infect mesophyll cells. In contrast, the family Luteoviridae includes RNA viruses that replicate and traffic exclusively in the phloem.

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Translational readthrough of the stop codon of the capsid protein (CP) open reading frame (ORF) is used by members of the to produce their minor capsid protein as a readthrough protein (RTP). The elements regulating RTP expression are not well understood, but they involve long-distance interactions between RNA domains. Using high-resolution mass spectrometry, glutamine and tyrosine were identified as the primary amino acids inserted at the stop codon of (PLRV) CP ORF.

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Potato tuber necrotic ringspot disease (PTNRD) is a tuber deformity associated with infection by the tuber necrotic strain of (PVY). PTNRD negatively impacts tuber quality and marketability, and poses a serious threat to seed and commercial potato production worldwide. PVY symptoms differ in the cultivars Waneta and Pike: Waneta expresses severe PTNRD and foliar mosaic with vein and leaf necrosis, whereas Pike does not express PTNRD and mosaic is the only foliar symptom.

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Classical breeding for virus resistance is a lengthy process and is restricted by the availability of resistance genes. Precise genome editing is a 'dream technology' to improve plants for virus resistance and these tools have opened new and very promising ways to generate virus resistant plants by disrupting host susceptibility genes, or by increasing the expression of viral resistance genes. However, precise targets must be identified and their roles understood to minimize potential negative effects on the plant.

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Protein interactions between virus and host are essential for viral propagation and movement, as viruses lack most of the proteins required to thrive on their own. Precision methods aimed at disrupting virus-host interactions represent new approaches to disease management but require in-depth knowledge of the identity and binding specificity of host proteins within these interaction networks. Protein coimmunoprecipitation (co-IP) coupled with mass spectrometry (MS) provides a high-throughput way to characterize virus-host interactomes in a single experiment.

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In the past decade recombinant strains of Potato virus Y (PVY) have overtaken the ordinary strain, PVY, as the predominant viruses affecting the US seed potato crop. Aphids may be a contributing factor in the emergence of the recombinant strains, but studies indicate that differences in transmission efficiency of individual PVY strains either from single or mixed infections, although variable, are not generally significant. Multiple strains of PVY are present in all potato production areas and common in many potato fields.

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Potato virus Y (PVY) exists as a complex of strains, including a growing number of recombinants. Evolution of PVY proceeds through accumulation of mutations and more rapidly through recombination. Here, the role of recombination in PVY evolution and the origin of common PVY recombinants were studied through whole genome analysis of 119 newly sequenced PVY isolates largely from U.

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Potato virus Y (PVY) is a serious threat to potato production due to effects on tuber yield and quality, in particular, due to induction of potato tuber necrotic ringspot disease (PTNRD), typically associated with recombinant strains of PVY. These recombinant strains have been spreading in the United States for the past several years, although the reasons for this continuing spread remained unclear. To document and assess this spread between 2011 and 2015, strain composition of PVY isolates circulating in the Columbia Basin potato production area was determined from hundreds of seed lots of various cultivars.

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There has been a recent shift in the prevalence of Potato virus Y (PVY) strains affecting potato with the ordinary strain PVY declining and the recombinant strains PVY and PVY emerging in the United States. Multiple PVY strains are commonly found in potato fields and even in individual plants. Factors contributing to the emergence of the recombinant strains are not well defined but differential aphid transmission of strains from single and mixed infections may play a role.

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The green peach aphid, , is a vector of the (PLRV, Luteoviridae), transmitted exclusively by aphids in a circulative manner. PLRV transmission efficiency was significantly reduced when a clonal lineage of was reared on turnip as compared with the weed physalis, and this was a transient effect caused by a host-switch response. A trend of higher PLRV titer in physalis-reared aphids as compared with turnip-reared aphids was observed at 24 h and 72 h after virus acquisition.

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Phloem localization of plant viruses is advantageous for acquisition by sap-sucking vectors but hampers host-virus protein interaction studies. In this study, Potato leafroll virus (PLRV)-host protein complexes were isolated from systemically infected potato, a natural host of the virus. Comparing two different co-immunoprecipitation (co-IP) support matrices coupled to mass spectrometry (MS), we identified 44 potato proteins and one viral protein (P1) specifically associated with virus isolated from infected phloem.

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