scholarly journals Manipulation of Aphid Behavior by a Persistent Plant Virus

2019 ◽  
Vol 93 (9) ◽  
Author(s):  
Maliheh Safari ◽  
Matthew J. Ferrari ◽  
Marilyn J. Roossinck
Keyword(s):  
Capsicum Annuum ◽  
Plant Virus ◽  
Horizontal Transmission ◽  
Plant Viruses ◽  
Host Cells ◽  
Content Type ◽  
Cryptic Virus ◽  
Pairwise Preference ◽  
Stark Contrast ◽  
Aphid Behavior

ABSTRACTPlants are frequently infected with cytoplasmic RNA viruses that persist for many generations through nearly 100% vertical transmission without producing any symptoms. Movement between plant cells and horizontal transmission have not been observed with these viruses; instead, they are distributed to all host cells through host cell division. Jalapeño peppers (Capsicum annuum) are all infected withPepper cryptic virus 1(PCV-1; familyPartitiviridae). We compared the effect of odor cues from PCV-1-infected (J+) and virus-free (J−) jalapeño peppers on the aphidMyzus persicae, a common vector of acute plant viruses. Pairwise preference experiments showed a stark contrast to insect-plant interactions in acute virus infections—that is, the virus-infected plants deterred aphids. The acute plant virusCucumber mosaic virus(CMV) manipulates its host's volatile emissions to attract aphid vectors and facilitate its transmission. We inoculated J+ and J− plants with CMV. Volatiles of J+ and J− CMV-infected plants were more attractive to aphids than those of J+ and J− mock-inoculated plants. However, in pairwise preference experiments with J+ CMV- and J− CMV-infected plants, aphids preferred the J− CMV volatile blend. Aphid reproduction on J+ and J− plants was measured as an indicator of the effect of PCV-1 on host quality for aphids. Aphid reproduction on J+ plants was more than 2-fold lower than that on J− plants.IMPORTANCEThis study demonstrates that a persistent plant virus can manipulate aphid behavior. This manipulation is in stark contrast to previously described effects of acute viruses on their hosts that facilitate their transmission. This study demonstrates a positive relationship betweenPepper cryptic virus 1and jalapeño pepper (Capsicum annuum) plants wherein the virus protects the plants from the vector of acute viruses and reduces aphid herbivory. This work reveals an important implication of persistent plant viruses for pest and pathogen management in agriculture.

scholarly journals A Unique 5′ Translation Element Discovered in Triticum Mosaic Virus

2015 ◽  
Vol 89 (24) ◽  
pp. 12427-12440 ◽  
Author(s):  
Robyn Roberts ◽  
Jincan Zhang ◽  
Laura K. Mayberry ◽  
Satyanarayana Tatineni ◽  
Karen S. Browning ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Translation Initiation ◽  
Plant Virus ◽  
Plant Viruses ◽  
Leader Sequence ◽  
Content Type ◽  
Internal Translation ◽  
Positive Strand Rna ◽  
Independent Translation

ABSTRACTSeveral plant viruses encode elements at the 5′ end of their RNAs, which, unlike most cellular mRNAs, can initiate translation in the absence of a 5′ m7GpppG cap. Here, we describe an exceptionally long (739-nucleotide [nt]) leader sequence in triticum mosaic virus (TriMV), a recently emerged wheat pathogen that belongs to thePotyviridaefamily of positive-strand RNA viruses. We demonstrate that the TriMV 5′ leader drives strong cap-independent translation in both wheat germ extract and oat protoplasts through a novel, noncanonical translation mechanism. Translation preferentially initiates at the 13th start codon within the leader sequence independently of eIF4E but involves eIF4G. We truncated the 5′ leader to a 300-nucleotide sequence that drives cap-independent translation from the 5′ end. We show that within this sequence, translation activity relies on a stem-loop structure identified at nucleotide positions 469 to 490. The disruption of the stem significantly impairs the function of the 5′ untranslated region (UTR) in driving translation and competing against a capped RNA. Additionally, the TriMV 5′ UTR can direct translation from an internal position of a bicistronic mRNA, and unlike cap-driven translation, it is unimpaired when the 5′ end is blocked by a strong hairpin in a monocistronic reporter. However, the disruption of the identified stem structure eliminates such a translational advantage. Our results reveal a potent and uniquely controlled translation enhancer that may provide new insights into mechanisms of plant virus translational regulation.IMPORTANCEMany members of thePotyviridaefamily rely on their 5′ end for translation. Here, we show that the 739-nucleotide-long triticum mosaic virus 5′ leader bears a powerful translation element with features distinct from those described for other plant viruses. Despite the presence of 12 AUG start codons within the TriMV 5′ UTR, translation initiates primarily at the 13th AUG codon. The TriMV 5′ UTR is capable of driving cap-independent translationin vitroandin vivo, is independent of eIF4E, and can drive internal translation initiation. A hairpin structure at nucleotide positions 469 to 490 is required for the cap-independent translation and internal translation initiation abilities of the element and plays a role in the ability of the TriMV UTR to compete against a capped RNAin vitro. Our results reveal a novel translation enhancer that may provide new insights into the large diversity of plant virus translation mechanisms.

scholarly journals Identification of Plant Virus Receptor Candidates in the Stylets of Their Aphid Vectors

2018 ◽  
Vol 92 (14) ◽  
Author(s):  
Craig G. Webster ◽  
Elodie Pichon ◽  
Manuella van Munster ◽  
Baptiste Monsion ◽  
Maëlle Deshoux ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Myzus Persicae ◽  
Plant Virus ◽  
Plant Viruses ◽  
Cauliflower Mosaic Virus ◽  
Insect Vectors ◽  
Virus Receptor ◽  
Content Type ◽  
Cuticular Proteins

ABSTRACTPlant viruses transmitted by insects cause tremendous losses in most important crops around the world. The identification of receptors of plant viruses within their insect vectors is a key challenge to understanding the mechanisms of transmission and offers an avenue for future alternative control strategies to limit viral spread. We here report the identification of two cuticular proteins within aphid mouthparts, and we provide experimental support for the role of one of them in the transmission of a noncirculative virus. These two proteins, named Stylin-01 and Stylin-02, belong to the RR-1 cuticular protein subfamily and are highly conserved among aphid species. Using an immunolabeling approach, they were localized in the maxillary stylets of the pea aphidAcyrthosiphon pisumand the green peach aphidMyzus persicae, in the acrostyle, an organ earlier shown to harbor receptors of a noncirculative virus. A peptide motif present at the C termini of both Stylin-01 and Stylin-02 is readily accessible all over the surface of the acrostyle. Competition forin vitrobinding to the acrostyle was observed between an antibody targeting this peptide and the helper component protein P2 ofCauliflower mosaic virus. Furthermore, silencing thestylin-01but notstylin-02gene through RNA interference decreased the efficiency ofCauliflower mosaic virustransmission byMyzus persicae. These results identify the first cuticular proteins ever reported within arthropod mouthparts and distinguish Stylin-01 as the best candidate receptor for the aphid transmission of noncirculative plant viruses.IMPORTANCEMost noncirculative plant viruses transmitted by insect vectors bind to their mouthparts. They are acquired and inoculated within seconds when insects hop from plant to plant. The receptors involved remain totally elusive due to a long-standing technical bottleneck in working with insect cuticle. Here we characterize the role of the two first cuticular proteins ever identified in arthropod mouthparts. A domain of these proteins is directly accessible at the surface of the cuticle of the acrostyle, an organ at the tip of aphid stylets. The acrostyle has been shown to bind a plant virus, and we consistently demonstrated that one of the identified proteins is involved in viral transmission. Our findings provide an approach to identify proteins in insect mouthparts and point at an unprecedented gene candidate for a plant virus receptor.

scholarly journals Within-Host Multiplication and Speed of Colonization as Infection Traits Associated with Plant Virus Vertical Transmission

2019 ◽  
Vol 93 (23) ◽  
Author(s):  
Alberto Cobos ◽  
Nuria Montes ◽  
Marisa López-Herranz ◽  
Miriam Gil-Valle ◽  
Israel Pagán
Keyword(s):  
Arabidopsis Thaliana ◽  
Mosaic Virus ◽  
Vertical Transmission ◽  
Plant Virus ◽  
Seed Transmission ◽  
Plant Viruses ◽  
Content Type ◽  
Seed Survival ◽  
Virus Interactions ◽  
Number Of Seeds

ABSTRACT Although vertical transmission from parents to offspring through seeds is an important fitness component of many plant viruses, very little is known about the factors affecting this process. Viruses reach the seed by direct invasion of the embryo and/or by infection of the ovules or the pollen. Thus, it can be expected that the efficiency of seed transmission would be determined by (i) virus within-host multiplication and movement, (ii) the ability of the virus to invade gametic tissues, (iii) plant seed production upon infection, and (iv) seed survival in the presence of the virus. However, these predictions have seldom been experimentally tested. To address this question, we challenged 18 Arabidopsis thaliana accessions with Turnip mosaic virus and Cucumber mosaic virus. Using these plant-virus interactions, we analyzed the relationship between the effect of virus infection on rosette and inflorescence weights; short-, medium-, and long-term seed survival; virulence; the number of seeds produced per plant; virus within-host speed of movement; virus accumulation in the rosette and inflorescence; and efficiency of seed transmission measured as a percentage and as the total number of infected seeds. Our results indicate that the best estimators of percent seed transmission are the within-host speed of movement and multiplication in the inflorescence. Together with these two infection traits, virulence and the number of seeds produced per infected plant were also associated with the number of infected seeds. Our results provide support for theoretical predictions and contribute to an understanding of the determinants of a process central to plant-virus interactions. IMPORTANCE One of the major factors contributing to plant virus long-distance dispersal is the global trade of seeds. This is because more than 25% of plant viruses can infect seeds, which are the main mode of germplasm exchange/storage, and start new epidemics in areas where they were not previously present. Despite the relevance of this process for virus epidemiology and disease emergence, the infection traits associated with the efficiency of virus seed transmission are largely unknown. Using turnip mosaic and cucumber mosaic viruses and their natural host Arabidopsis thaliana as model systems, we have identified the within-host speed of virus colonization and multiplication in the reproductive structures as the main determinants of the efficiency of seed transmission. These results contribute to shedding light on the mechanisms by which plant viruses disperse and optimize their fitness and may help in the design of more-efficient strategies to prevent seed infection.

scholarly journals A High-Throughput Method for Screening for Genes Controlling Bacterial Conjugation of Antibiotic Resistance

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
pp. e01226-20
Author(s):  
Hanna Alalam ◽  
Fabrice E. Graf ◽  
Martin Palm ◽  
Marie Abadikhah ◽  
Martin Zackrisson ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Horizontal Transmission ◽  
Antibiotic Resistance Genes ◽  
Host Cells ◽  
The Novel ◽  
Content Type ◽  
Rapid Construction ◽  
Cost Efficient ◽  
Efficient Screening ◽  
New Framework

ABSTRACTThe rapid horizontal transmission of antibiotic resistance genes on conjugative plasmids between bacterial host cells is a major cause of the accelerating antibiotic resistance crisis. There are currently no experimental platforms for fast and cost-efficient screening of genetic effects on antibiotic resistance transmission by conjugation, which prevents understanding and targeting conjugation. We introduce a novel experimental framework to screen for conjugation-based horizontal transmission of antibiotic resistance between >60,000 pairs of cell populations in parallel. Plasmid-carrying donor strains are constructed in high-throughput. We then mix the resistance plasmid-carrying donors with recipients in a design where only transconjugants can reproduce, measure growth in dense intervals, and extract transmission times as the growth lag. As proof-of-principle, we exhaustively explore chromosomal genes controlling F-plasmid donation within Escherichia coli populations, by screening the Keio deletion collection in high replication. We recover all seven known chromosomal gene mutants affecting conjugation as donors and identify many novel mutants, all of which diminish antibiotic resistance transmission. We validate nine of the novel genes’ effects in liquid mating assays and complement one of the novel genes’ effect on conjugation (rseA). The new framework holds great potential for exhaustive disclosing of candidate targets for helper drugs that delay resistance development in patients and societies and improve the longevity of current and future antibiotics. Further, the platform can easily be adapted to explore interspecies conjugation, plasmid-borne factors, and experimental evolution and be used for rapid construction of strains.IMPORTANCE The rapid transmission of antibiotic resistance genes on conjugative plasmids between bacterial host cells is a major cause of the accelerating antibiotic resistance crisis. There are currently no experimental platforms for fast and cost-efficient screening of genetic effects on antibiotic resistance transmission by conjugation, which prevents understanding and targeting conjugation. We introduce a novel experimental framework to screen for conjugation-based horizontal transmission of antibiotic resistance between >60,000 pairs of cell populations in parallel. As proof-of-principle, we exhaustively explore chromosomal genes controlling F-plasmid donation within E. coli populations. We recover all previously known and many novel chromosomal gene mutants that affect conjugation efficiency. The new framework holds great potential for rapid screening of compounds that decrease transmission. Further, the platform can easily be adapted to explore interspecies conjugation, plasmid-borne factors, and experimental evolution and be used for rapid construction of strains.

scholarly journals Softening of Processed Plant Virus Infected Cucumis sativus Fruits

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1451
Author(s):  
Anne-Katrin Kersten ◽  
Sabrina Scharf ◽  
Martina Bandte ◽  
Peer Martin ◽  
Peter Meurer ◽  
...  
Keyword(s):  
Cucumis Sativus ◽  
Plant Virus ◽  
Plant Viruses ◽  
Economic Losses ◽  
Symptom Expression ◽  
Considerable Influence ◽  
Mechanical Inoculation ◽  
Morphological Alterations ◽  
Texture Properties ◽  
Textural Changes

Texture softening of pickled cucumbers does not meet consumers’ quality expectations and leads to economic losses. The factor(s) triggering this phenomenon is still unknown. We investigated the importance of plant viruses such as Cucumber green mottle mosaic tobamovirus (CGMMV) and Zucchini yellow mosaic potyvirus (ZYMV) in the context of softening of pickles. Cucumber plants (Cucumis sativus) were infected by mechanical inoculation, grown under greenhouse conditions and tested positive for the viral infection by ELISA. The severity of virus infection was reflected in yield and symptom expression. Histological and morphological alterations were observed. All fruits were pasteurized, separately stored in jars and subjected to texture measurements after four, six and 12 months. CGMMV-infections were asymptomatic or caused mild symptoms on leaves and fruit, and texture quality was comparable to control. At the same time, fruits of ZYMV-infected plants showed severe symptoms like deformations and discoloration, as well as a reduction in firmness and crunchiness after pasteurization. In addition, histological alterations were detected in such fruits, possibly causing textural changes. We conclude that plant viruses could have a considerable influence on the firmness and crunchiness of pickled cucumbers after pasteurization. It is possible that the severity of symptom expression has an influence on texture properties.

scholarly journals hfqPlays Important Roles in Virulence and Stress Adaptation in Cronobacter sakazakii ATCC 29544

2015 ◽  
Vol 83 (5) ◽  
pp. 2089-2098 ◽  
Author(s):  
Seongok Kim ◽  
Hyelyeon Hwang ◽  
Kwang-Pyo Kim ◽  
Hyunjin Yoon ◽  
Dong-Hyun Kang ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Soft Agar ◽  
Host Cells ◽  
Neonatal Meningitis ◽  
Animal Cells ◽  
Content Type ◽  
Flagellar Biosynthesis

Cronobacterspp. are opportunistic pathogens that cause neonatal meningitis and sepsis with high mortality in neonates. Despite the peril associated withCronobacterinfection, the mechanisms of pathogenesis are still being unraveled. Hfq, which is known as an RNA chaperone, participates in the interaction with bacterial small RNAs (sRNAs) to regulate posttranscriptionally the expression of various genes. Recent studies have demonstrated that Hfq contributes to the pathogenesis of numerous species of bacteria, and its roles are varied between bacterial species. Here, we tried to elucidate the role of Hfq inC. sakazakiivirulence. In the absence ofhfq,C. sakazakiiwas highly attenuated in disseminationin vivo, showed defects in invasion (3-fold) into animal cells and survival (103-fold) within host cells, and exhibited low resistance to hydrogen peroxide (102-fold). Remarkably, the loss ofhfqled to hypermotility on soft agar, which is contrary to what has been observed in other pathogenic bacteria. The hyperflagellated bacteria were likely to be attributable to the increased transcription of genes associated with flagellar biosynthesis in a strain lackinghfq. Together, these data strongly suggest thathfqplays important roles in the virulence ofC. sakazakiiby participating in the regulation of multiple genes.

scholarly journals Novel Functional Genomics Approaches: A Promising Future in the Combat Against Plant Viruses

2016 ◽  
Vol 106 (10) ◽  
pp. 1231-1239 ◽  
Author(s):  
Vincent N. Fondong ◽  
Ugrappa Nagalakshmi ◽  
Savithramma P. Dinesh-Kumar
Keyword(s):  
Functional Genomics ◽  
Plant Virus ◽  
Reverse Genetics ◽  
Plant Viruses ◽  
Micro Rna ◽  
Viral Genomes ◽  
Virus Control ◽  
Local Lesions ◽  
Short Palindromic Repeat ◽  
Interfering Rna

Advances in functional genomics and genome editing approaches have provided new opportunities and potential to accelerate plant virus control efforts through modification of host and viral genomes in a precise and predictable manner. Here, we discuss application of RNA-based technologies, including artificial micro RNA, transacting small interfering RNA, and Cas9 (clustered regularly interspaced short palindromic repeat–associated protein 9), which are currently being successfully deployed in generating virus-resistant plants. We further discuss the reverse genetics approach, targeting induced local lesions in genomes (TILLING) and its variant, known as EcoTILLING, that are used in the identification of plant virus recessive resistance gene alleles. In addition to describing specific applications of these technologies in plant virus control, this review discusses their advantages and limitations.

scholarly journals Inflammasome Activation Contributes to Interleukin-23 Production in Response to Clostridium difficile

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Carrie A. Cowardin ◽  
Sarah A. Kuehne ◽  
Erica L. Buonomo ◽  
Chelsea S. Marie ◽  
Nigel P. Minton ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Disease Severity ◽  
Tissue Damage ◽  
The United States ◽  
Host Cells ◽  
Inflammasome Activation ◽  
Content Type ◽  
Danger Signals ◽  
Interleukin 23 ◽  
Molecular Patterns

ABSTRACT  Clostridium difficileis the most common hospital-acquired pathogen, causing antibiotic-associated diarrhea in over 250,000 patients annually in the United States. Disease is primarily mediated by toxins A and B, which induce potent proinflammatory signaling in host cells and can activate an ASC-containing inflammasome. Recent findings suggest that the intensity of the host response to infection correlates with disease severity. Our lab has identified the proinflammatory cytokine interleukin-23 (IL-23) as a pathogenic mediator during C. difficile infection (CDI). The mechanisms by which C. difficile induces IL-23, however, are not well understood, and the role of toxins A and B in this process is unclear. Here, we show that toxins A and B alone are not sufficient for IL-23 production but synergistically increase the amount of IL-23 produced in response to MyD88-dependent danger signals, including pathogen-associated molecular patterns (PAMPs) and host-derived damage associated molecular patterns (DAMPs). Danger signals also enhanced the secretion of IL-1β in response to toxins A and B, and subsequent IL-1 receptor signaling accounted for the majority of the increase in IL-23 that occurred in the presence of the toxins. Inhibition of inflammasome activation in the presence of extracellular K+likewise decreased IL-23 production. Finally, we found that IL-1β was increased in the serum of patients with CDI, suggesting that this systemic response could influence downstream production of pathogenic IL-23. Identification of the synergy of danger signals with toxins A and B via inflammasome signaling represents a novel finding in the mechanistic understanding of C. difficile-induced inflammation.IMPORTANCEClostridium difficileis among the leading causes of death due to health care-associated infection, and factors determining disease severity are not well understood. C. difficile secretes toxins A and B, which cause inflammation and tissue damage, and recent findings suggest that some of this tissue damage may be due to an inappropriate host immune response. We have found that toxins A and B, in combination with both bacterium- and host-derived danger signals, can induce expression of the proinflammatory cytokines IL-1β and IL-23. Our results demonstrate that IL-1β signaling enhances IL-23 production and could lead to increased pathogenic inflammation during CDI.

scholarly journals Neurotrophin Receptor TrkC Is an Entry Receptor for Trypanosoma cruzi in Neural, Glial, and Epithelial Cells

2011 ◽  
Vol 79 (10) ◽  
pp. 4081-4087 ◽  
Author(s):  
Craig Weinkauf ◽  
Ryan Salvador ◽  
Mercio PereiraPerrin
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Mammalian Cells ◽  
Chinese Hamster ◽  
Neuronal Cell ◽  
Host Cells ◽  
Neurotrophin Receptor ◽  
Content Type

ABSTRACTTrypanosoma cruzi, the agent of Chagas' disease, infects a variety of mammalian cells in a process that includes multiple cycles of intracellular division and differentiation starting with host receptor recognition by a parasite ligand(s). Earlier work in our laboratory showed that the neurotrophin-3 (NT-3) receptor TrkC is activated byT. cruzisurfacetrans-sialidase, also known as parasite-derived neurotrophic factor (PDNF). However, it has remained unclear whether TrkC is used byT. cruzito enter host cells. Here, we show that a neuronal cell line (PC12-NNR5) relatively resistant toT. cruzibecame highly susceptible to infection when overexpressing human TrkC but not human TrkB. Furthermore,trkCtransfection conferred an ∼3.0-fold intracellular growth advantage. Sialylation-deficient Chinese hamster ovarian (CHO) epithelial cell lines Lec1 and Lec2 also became much more permissive toT. cruziafter transfection with thetrkCgene. Additionally, NT-3 specifically blockedT. cruziinfection of the TrkC-NNR5 transfectants and of naturally permissive TrkC-bearing Schwann cells and astrocytes, as did recombinant PDNF. Two specific inhibitors of Trk autophosphorylation (K252a and AG879) and inhibitors of Trk-induced MAPK/Erk (U0126) and Akt kinase (LY294002) signaling, but not an inhibitor of insulin-like growth factor 1 receptor, abrogated TrkC-mediated cell invasion. Antibody to TrkC blockedT. cruziinfection of the TrkC-NNR5 transfectants and of cells that naturally express TrkC. The TrkC antibody also significantly and specifically reduced cutaneous infection in a mouse model of acute Chagas' disease. TrkC is ubiquitously expressed in the peripheral and central nervous systems, and in nonneural cells infected byT. cruzi, including cardiac and gastrointestinal muscle cells. Thus, TrkC is implicated as a functional PDNF receptor in cell entry, independently of sialic acid recognition, mediating broadT. cruziinfection bothin vitroandin vivo.

Sign in / Sign up

Export Citation Format

Share Document