scholarly journals The Amino-Proximal Region of the Coat Protein of Cucumber Vein Yellowing Virus (Family Potyviridae) Affects the Infection Process and Whitefly Transmission

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2771
Author(s):  
Svenja Lindenau ◽  
Stephan Winter ◽  
Paolo Margaria
Keyword(s):  
Coat Protein ◽  
Deletion Mutant ◽  
Severe Disease ◽  
Plant Viruses ◽  
Proximal Region ◽  
Infection Process ◽  
Virus Family ◽  
Whitefly Transmission ◽  
Plant Infection ◽  
Yellowing Virus

Most plant viruses rely on vector transmission for their spread and specific interactions between vector and virus have evolved to regulate this relationship. The whitefly Bemisia tabaci- transmitted cucumber vein yellowing virus (CVYV; genus Ipomovirus, family Potyviridae) is endemic in the Mediterranean Basin, where it causes significant losses in cucurbit crops. In this study, the role of the coat protein (CP) of CVYV for B. tabaci transmission and plant infection was investigated using a cloned and infectious CVYV cDNA and a collection of point and deletion mutants derived from this clone. Whitefly transmission of CVYV was abolished in a deletion mutant lacking amino acids in position 93–105 of the CP. This deletion mutant caused more severe disease symptoms compared to the cDNA clone representing the wild-type (wt) virus and movement efficiency was likewise affected. Two virus mutants carrying a partially restored CP were transmissible and showed symptoms comparable to the wt virus. Collectively, our data demonstrate that the N-terminus of the CVYV CP is a determinant for transmission by the whitefly vector and is involved in plant infection and symptom expression.

scholarly journals Mutations in the coat protein of a begomovirus result in altered transmission by different species of whitefly vectors

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Li-Long Pan ◽  
Yao Chi ◽  
Chao Liu ◽  
Yun-Yun Fan ◽  
Shu-Sheng Liu
Keyword(s):  
Genetic Variation ◽  
Coat Protein ◽  
Plant Viruses ◽  
Virus Infectivity ◽  
Insect Vector ◽  
Host Interactions ◽  
Whitefly Transmission ◽  
Virus Acquisition ◽  
Plant Infection ◽  
The Impact

Abstract For many crop pathogens including viruses, high genetic variation provides them with potential to adapt to and prevail in a changing environment. Understanding genetic variation in viruses and their significance is a key to elaborate virus epidemiology and evolution. While genetic variation of plant viruses has been documented to impact virus–host interactions, how it affects virus–insect vector interactions remains elusive. Here, we report the impact of mutations in the coat protein of squash leaf curl China virus (SLCCNV), a begomovirus, on the interaction between the virus and its whitefly vectors. We characterized mutations in the coat protein of SLCCNV and found that some residues exhibited higher mutation frequency than the others. We assayed the impact of mutation on infectivity using agroinoculation and found these mutations marginally affect virus infectivity. We further analyze their functions using virus acquisition and transmission trials and found some of mutations resulted in altered transmission of SLCCNV by different species of the whitefly Bemisia tabaci complex. We then identified the key amino acid residue(s) involved by constructing several mutant viruses and found that a single-residue mutation in the coat protein of SLCCNV was sufficient to significantly alter the whitefly transmission characteristics of SLCCNV. We examined the competition between different genotypes of SLCCNV in plant infection and whitefly transmission. We found that mutations in the coat protein did not alter the fitness of SLCCNV in plants, but they rendered the virus more competitive in transmission by certain species of whiteflies. Our findings indicate that mutations in the coat protein may play a key role in both the adaptation of begomoviruses to the changing vector populations and the evolution of begomoviruses.

Research Advances in Potyviruses: From the Laboratory Bench to the Field

2021 ◽  
Vol 59 (1) ◽  
Author(s):  
Xiuling Yang ◽  
Yinzi Li ◽  
Aiming Wang
Keyword(s):  
Control Strategies ◽  
Genetic Resistance ◽  
Plant Viruses ◽  
Infection Process ◽  
Future Research ◽  
Annual Review ◽  
Publication Date ◽  
Viral Pathogens ◽  
Genome Expression ◽  
Amount Of Knowledge

Potyviruses (viruses in the genus Potyvirus, family Potyviridae) constitute the largest group of known plant-infecting RNA viruses and include many agriculturally important viruses that cause devastating epidemics and significant yield losses in many crops worldwide. Several potyviruses are recognized as the most economically important viral pathogens. Therefore, potyviruses are more studied than other groups of plant viruses. In the past decade, a large amount of knowledge has been generated to better understand potyviruses and their infection process. In this review, we list the top 10 economically important potyviruses and present a brief profile of each. We highlight recent exciting findings on the novel genome expression strategy and the biological functions of potyviral proteins and discuss recent advances in molecular plant–potyvirus interactions, particularly regarding the coevolutionary arms race. Finally, we summarize current disease control strategies, with a focus on biotechnology-based genetic resistance, and point out future research directions. Expected final online publication date for the Annual Review of Phytopathology, Volume 59 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Nucleo-cytoplasmic shuttling of VPg encoded by Wheat yellow mosaic virus requires association with the coat protein

2013 ◽  
Vol 94 (12) ◽  
pp. 2790-2802 ◽  
Author(s):  
Liying Sun ◽  
Bian Jing ◽  
Ida Bagus Andika ◽  
Yingchun Hu ◽  
Bingjian Sun ◽  
...  
Keyword(s):  
Coat Protein ◽  
Nuclear Export ◽  
Fluorescent Protein ◽  
Nuclear Export Signal ◽  
Plant Viruses ◽  
Yellow Mosaic Virus ◽  
Virus Protein ◽  
Wheat Yellow Mosaic Virus ◽  
Nuclear Targeting ◽  
Cytoplasmic Transport

VPg (virus protein, genome-linked) is a multifunctional protein that plays important roles in viral multiplication in the cytoplasm. However, a number of VPgs encoded by plant viruses target the nucleus and this appears to be biologically significant. These VPgs may therefore be translocated between nuclear and cytoplasmic compartments during virus infection, but such nucleo-cytoplasmic transport has not been demonstrated. We report that VPg encoded by Wheat yellow mosaic virus (WYMV, genus Bymovirus, family Potyviridae) accumulated in both the nucleus and cytoplasm of infected cells, but localized exclusively in the nucleus when expressed alone in plants. Computational analyses predicted the presence of a nuclear localization signal (NLS) and a nuclear export signal (NES) in WYMV VPg. Mutational analyses showed that both the N-terminal and the NLS domains of VPg contribute to the efficiency of nuclear targeting. In vitro and in planta assays indicated that VPg interacts with WYMV coat protein (CP) and proteinase 1 (P1) proteins. Observation of VPg fused to a fluorescent protein and subcellular fractionation experiments showed that VPg was translocated to the cytoplasm when co-expressed with CP, but not with P1. Mutations in the NES domain or treatment with leptomycin B prevented VPg translocation to the cytoplasm when co-expressed with CP. Our results suggest that association with CP facilitates the nuclear export of VPg during WYMV infection.

Association of the IVR Gene with Virus Localization and Resistance

1995 ◽  
Author(s):  
Gad Loebenstein ◽  
William Dawson ◽  
Abed Gera
Keyword(s):  
Amino Acids ◽  
Coat Protein ◽  
Plant Viruses ◽  
Full Length ◽  
N Gene ◽  
Complete Suppression ◽  
Coat Proteins ◽  
Nicotiana Glutinosa ◽  
Nicotiana Debneyi ◽  
Full Length Gene

We have reported that localization of TMV in tobacco cultivars with the N gene, is associated with a 23 K protein (IVR) that inhibited replication of several plant viruses. This protein was also found in induced resistant tissue of Nicotiana glutinosa x Nicotiana debneyi. During the present grant we found that TMV production is enhanced in protoplasts and plants of local lesion responding tobacco cultivars exposed to 35oC, parallel to an almost complete suppression of the production of IVR. We also found that IVR is associated with resistance mechanisms in pepper cultivars. We succeeded to clone the IVR gene. In the first attempt we isolated a clone - "101" which had a specific insert of 372 bp (the full length gene for the IVR protein of 23 kD should be around 700 bp). However, attempts to isolate the full length gene did not give clear cut results, and we decided not to continue with this clone. The amino acid sequence of the N-terminus of IVR was determined and an antiserum was prepared against a synthetic peptide representing amino acids residues 1-20 of IVR. Using this antiserum as well as our polyclonal antiserum to IVR a new clone NC-330 was isolated using lamba-ZAP library. This NC-330 clone has an insert of about 1 kB with an open reading frame of 596 bp. This clone had 86.6% homology with the first 15 amino acids of the N-terminal part of IVR and 61.6% homology with the first 23 amino acids of IVR. In the QIA expression system and western blotting of the expressed protein, a clear band of about 21 kD was obtained with IVR antiserum. This clone was used for transformation of Samsun tobacco plants and we have presently plantlets which were rooted on medium containing kanamycin. Hybridization with this clone was also obtained with RNA from induced resistant tissue of Samsun NN but not with RNA from healthy control tissue of Samsun NN, or infected or healthy tissue of Samsun. This further strengthens the previous data that the NC 330 clone codes for IVR. In the U.S. it was shown that IVR is induced in plants containing the N' gene when infected with mutants of TMV that elicit the HR. This is a defined system in which the elicitor is known to be due to permutations of the coat protein which can vary in elicitor strength. The objective was to understand how IVR synthesis is induced after recognition of elicitor coat protein in the signal transduction pathway that leads to HR. We developed systems to manipulate induction of IVR by modifying the elicitor and are using these elicitor molecules to isolate the corresponding plant receptor molecules. A "far-western" procedure was developed that found a protein from N' plants that specifically bind to elicitor coat proteins. This protein is being purified and sequenced. This objective has not been completed and is still in progress. We have reported that localization of TMV in tobacco cultivars with the N gene, is associated with a 23 K protein (IVR) that inhibited replication of several plant viruses. This protein was also found in induced resistant tissue of Nicotiana glutinosa x Nicotiana debneyi.

scholarly journals The Cucumber vein yellowing virus Silencing Suppressor P1b Can Functionally Replace HCPro in Plum pox virus Infection in a Host-Specific Manner

2012 ◽  
Vol 25 (2) ◽  
pp. 151-164 ◽  
Author(s):  
Alberto Carbonell ◽  
Gabriela Dujovny ◽  
Juan Antonio García ◽  
Adrian Valli
Keyword(s):  
Rna Silencing ◽  
Deleterious Effect ◽  
Prunus Persica ◽  
Plant Viruses ◽  
Natural Host ◽  
Plum Pox Virus ◽  
Silencing Suppressor ◽  
Specific Manner ◽  
Silencing Suppression ◽  
Yellowing Virus

Plant viruses of the genera Potyvirus and Ipomovirus (Potyviridae family) use unrelated RNA silencing suppressors (RSS) to counteract antiviral RNA silencing responses. HCPro is the RSS of Potyvirus spp., and its activity is enhanced by the upstream P1 protein. Distinctively, the ipomovirus Cucumber vein yellowing virus (CVYV) lacks HCPro but contains two P1 copies in tandem (P1aP1b), the second of which functions as RSS. Using chimeras based on the potyvirus Plum pox virus (PPV), we found that P1b can functionally replace HCPro in potyviral infections of Nicotiana plants. Interestingly, P1a, the CVYV protein homologous to potyviral P1, disrupted the silencing suppression activity of P1b and reduced the infection efficiency of PPV in Nicotiana benthamiana. Testing the influence of RSS in host specificity, we found that a P1b-expressing chimera poorly infected PPV's natural host, Prunus persica. Conversely, P1b conferred on PPV chimeras the ability to replicate locally in cucumber, CVYV's natural host. The deleterious effect of P1a on PPV infection is host dependent, because the P1aP1b-expressing PPV chimera accumulated in cucumber to higher levels than PPV expressing P1b alone. These results demonstrate that a potyvirus can use different RSS, and that particular RSS and upstream P1-like proteins contribute to defining the virus host range.

scholarly journals Stable Fluorescent and Enzymatic Tagging of Bradyrhizobium diazoefficiens to Analyze Host-Plant Infection and Colonization

2015 ◽  
Vol 28 (9) ◽  
pp. 959-967 ◽  
Author(s):  
Raphael Ledermann ◽  
Ilka Bartsch ◽  
Mitja N. Remus-Emsermann ◽  
Julia A. Vorholt ◽  
Hans-Martin Fischer
Keyword(s):  
Fluorescent Proteins ◽  
Root Nodules ◽  
Microscopic Analysis ◽  
Single Copy ◽  
Infection Process ◽  
Model Systems ◽  
Nodule Occupancy ◽  
Developmental Program ◽  
Plant Infection ◽  
Host Infection

Bradyrhizobium diazoefficiens USDA 110 (formerly named Bradyrhizobium japonicum) can fix dinitrogen when living as an endosymbiont in root nodules of soybean and some other legumes. Formation of a functional symbiosis relies on a defined developmental program mediated by controlled gene expression in both symbiotic partners. In contrast to other well-studied Rhizobium-legume model systems that have been thoroughly examined by means of genetically tagged strains, analysis of B. diazoefficiens host infection has been impaired due to the lack of suitable tagging systems. Here, we describe the construction of B. diazoefficiens strains constitutively expressing single-copy genes for fluorescent proteins (eBFP2, mTurquoise2, GFP+, sYFP2, mCherry, HcRed) and enzymes (GusA, LacZ). For stable inheritance, the constructs were recombined into the chromosome. Effectiveness and versatility of the tagged strains was demonstrated in plant infection assays. (i) The infection process was followed from root-hair attachment to colonization of nodule cells with epifluorescent microscopy. (ii) Monitoring mixed infections with two strains producing different fluorescent proteins allowed rapid analysis of nodule occupancy and revealed that the majority of nodules contained clonal populations. (iii) Microscopic analysis of nodules induced by fluorescent strains provided evidence for host-dependent control of B. diazoefficiens bacteroid morphology in nodules of Aeschynomene afraspera and Arachis hypogaea (peanut), as deduced from their altered morphology compared with bacteroids in soybean nodules.

scholarly journals Conversion in the Requirement of Coat Protein in Cell-to-Cell Movement Mediated by the Cucumber Mosaic Virus Movement Protein

2001 ◽  
Vol 75 (17) ◽  
pp. 8045-8053 ◽  
Author(s):  
Hideaki Nagano ◽  
Kazuyuki Mise ◽  
Iwao Furusawa ◽  
Tetsuro Okuno
Keyword(s):  
Amino Acids ◽  
Coat Protein ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Plant Viruses ◽  
Brome Mosaic Virus ◽  
Viral Movement ◽  
Intercellular Movement

ABSTRACT Plant viruses have movement protein (MP) gene(s) essential for cell-to-cell movement in hosts. Cucumber mosaic virus (CMV) requires its own coat protein (CP) in addition to the MP for intercellular movement. Our present results using variants of both CMV and a chimeric Brome mosaic virus with the CMV MP gene revealed that CMV MP truncated in its C-terminal 33 amino acids has the ability to mediate viral movement independently of CP. Coexpression of the intact and truncated CMV MPs extremely reduced movement of the chimeric viruses, suggesting that these heterogeneous CMV MPs function antagonistically. Sequential deletion analyses of the CMV MP revealed that the dispensability of CP occurred when the C-terminal deletion ranged between 31 and 36 amino acids and that shorter deletion impaired the ability of the MP to promote viral movement. This is the first report that a region of MP determines the requirement of CP in cell-to-cell movement of a plant virus.

scholarly journals Genome wide identification of bacterial genes required for plant infection by Tn-seq

2017 ◽  
Author(s):  
Kevin Royet ◽  
Nicolas Parisot ◽  
Agnès Rodrigue ◽  
Erwan Gueguen ◽  
Guy Condemine
Keyword(s):  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
High Throughput Sequencing ◽  
Plant Cell Wall ◽  
Infection Process ◽  
Cell Wall Degrading Enzymes ◽  
Plant Pathogenic Bacteria ◽  
Regulatory Cascade ◽  
Plant Infection ◽  
Genome Wide

ABSTRACTSoft rot enterobacteria (DickeyaandPectobacterium) are major pathogens that cause diseases on plants of agricultural importance such as potato and ornamentals. Long term studies to identify virulence factors of these bacteria focused mostly on plant cell wall degrading enzymes secreted by the type II secretion system and the regulation of their expression. To identify new virulence factors we performed a Tn-seq genome-wide screen of a transposon mutant library during chicory infection followed by high-throughput sequencing. This allowed the detection of mutants with reduced but also increased fitness in the plant. Virulence factors identified differed from those previously known since diffusible ones (secreted enzymes, siderophores or metabolites) were not detected by this screen. In addition to genes encoding proteins of unknown function that could be new virulence factors, others could be assigned to known biological functions. The central role of the FlhDC regulatory cascade in the control of virulence was highlighted with the identification of new members of this pathway. Scarcity of the plant in certain amino acids and nucleic acids required presence of the corresponding biosynthetic genes in the bacteria. Their products could be targets for the development of antibacterial compounds. Among the genes required for full development in chicory we also identified six genes involved in the glycosylation of the flagellin FliC, glycosylation, which in other plant pathogenic bacteria contributes to virulence.Author summaryIdentification of virulence factors of plant pathogenic bacteria has relied on the test of individual mutants on plants, a time-consuming method. New methods like transcriptomic or proteomic can now be used but they only allow the identification of genes induced during the infection process and non-induced genes may be missed. Tn-seq is a very powerful method to identify genes required for bacterial growth in their host. We used for the first time this method in a plant pathogenic bacteria to identify genes required for the multiplication ofDickeya dadantiiin chicory. We identified about 100 genes with decreased or increased fitness in the plant. Most of them had no previously described role in bacterial virulence. We unveiled important metabolic genes and regulators of motility and virulence. We showed thatD. dadantiiflagellin is glycosylated and that this modification confers fitness to the bacteria during plant infection. Our work opens the way to the use of Tn-seq with bacterial phytopathogens. Assay by this method of large collections of environmental pathogenic strains now available will allow an easy and rapid identification of new virulence factors.

scholarly journals Characterization and Establishment of a Recombinase Polymerase Amplification Assay for Rapid Detection of Tomato Spotted Wilt Virus in Pepper

2021 ◽  
Author(s):  
Kaiqiang Hao ◽  
Ming Gu ◽  
Miaoren Yang ◽  
Xinran Gao ◽  
Zihao Xia ◽  
...  
Keyword(s):  
Coat Protein ◽  
Phylogenetic Tree ◽  
Rapid Detection ◽  
Northeast China ◽  
Tomato Spotted Wilt Virus ◽  
Plant Viruses ◽  
Recombinase Polymerase Amplification ◽  
Liaoning Province ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

Abstract Tomato spotted wilt virus (TSWV) is one of the most economically destructive and scientifically challenging plant viruses, which has seriously affected the production of commercial crops. At present, there is no effective strategy to control this virus. Therefore, there is an urgent need for a rapid and simple method to detect TSWV, which is of great significance to prevent its spread. In this study, an isolate of TSWV (TSWV-LNTL) infecting pepper from Liaoning Province of northeast China was obtained. A phylogenetic tree based on neighbor-joining using coat protein (CP) gene was established. A rapid method for detecting TSWV by recombinase polymerase amplification (RPA) was established. The phylogenetic tree based on the nucleotide sequences of coat protein (CP) genes of different TSWV isolates showed that the genetic relationship of TSWV-LNTL was most closely related to that of TSWV-LX-Lettuce-12 (Yunnan) and TSWV-TSHL (Shandong) isolates in China. It can be finished at 39 °C for 20 min and then purified by heating at 65 °C for 10 min. The RPA primers were highly specific and no cross-reactivity was detected with other selected viruses infecting pepper. The results of sensitivity test revealed that the detection limit of RPA is 1.0 × 103 copies/μL, which was tenfold lower than that of PCR method. In addition, the RPA method was successfully applied to detect TSWV in field samples. These results reported the occurrence of TSWV on crop in Liaoning Province of northeast China and demonstrated that the established RPA assay provided an effective molecular diagnostic tool for the accurate and rapid detection of TSWV to prevent its spread.

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