Injured cells required for the initiation of plant virus infections

1969 ◽  
Vol 47 (3) ◽  
pp. 499-500 ◽  
Author(s):  
W. C. Kimmins ◽  
M. D. Casselman

To investigate whether a plant virus infection could be initiated in uninjured cells, the trifoliate leaves of Phaseolus vulgaris var. Prince were dipped into suspensions of tobacco necrosis virus. It is concluded that infection can only be established through injured leaf cells.

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 524
Author(s):  
Daniela Bulgari ◽  
Nicola Landi ◽  
Sara Ragucci ◽  
Franco Faoro ◽  
Antimo Di Maro

Using the pathosystem Phaseolus vulgaris–tobacco necrosis virus (TNV), we demonstrated that PD-L1 and PD-L4, type-1 ribosome inactivating proteins (RIPs) from leaves of Phytolacca dioica L., possess a strong antiviral activity. This activity was exerted both when the RIPs and the virus were inoculated together in the same leaf and when they were inoculated or applied separately in the adaxial and abaxial leaf surfaces. This suggests that virus inhibition would mainly occur inside plant cells at the onset of infection. Histochemical studies showed that both PD-L1 and PD-L4 were not able to induce oxidative burst and cell death in treated leaves, which were instead elicited by inoculation of the virus alone. Furthermore, when RIPs and TNV were inoculated together, no sign of H2O2 deposits and cell death were detectable, indicating that the virus could have been inactivated in a very early stage of infection, before the elicitation of a hypersensitivity reaction. In conclusion, the strong antiviral activity is likely exerted inside host cells as soon the virus disassembles to start translation of the viral genome. This activity is likely directed towards both viral and ribosomal RNA, explaining the almost complete abolition of infection when virus and RIP enter together into the cells.


2001 ◽  
Vol 75 (24) ◽  
pp. 12288-12297 ◽  
Author(s):  
F. Tenllado ◽  
J. R. Dı́az-Ruı́z

ABSTRACT Double-stranded RNA (dsRNA) has been shown to play a key role as an inducer of different interference phenomena occurring in both the plant and animal kingdoms. Here, we show that dsRNA derived from viral sequences can interfere with virus infection in a sequence-specific manner by directly delivering dsRNA to leaf cells either by mechanical inoculation or via an Agrobacterium-mediated transient-expression assay. We have successfully interfered with the infection of plants by three viruses belonging to the tobamovirus, potyvirus, and alfamovirus groups, demonstrating the reliability of the approach. We suggest that the effect mediated by dsRNA in plant virus infection resembles the analogous phenomenon of RNA interference observed in animals. The interference observed is sequence specific, is dose dependent, and is triggered by dsRNA but not single-stranded RNA. Our results support the view that a dsRNA intermediate in virus replication acts as efficient initiator of posttranscriptional gene silencing (PTGS) in natural virus infections, triggering the initiation step of PTGS that targets viral RNA for degradation.


1979 ◽  
Vol 25 (4) ◽  
pp. 557-567
Author(s):  
Craig R. Hibben ◽  
Robert F. Bozarth ◽  
Judith Reese

Abstract Aspen (Populus tremuloides) is deteriorating in some sites in the middle Rocky Mountain region. Several causal factors have been implicated, but the exact etiology of aspen deterioration remains unknown. Foliar symptoms indicative of virus infection were observed in trees within 33 aspen clones, both deteriorating and nondeteriorating, in Utah. A virus was mechanically transmitted from five deteriorating clones to cowpea (Vigna unguiculata). Sucrose density-gradient centrifugation of one isolate of the virus revealed a single infectious component with a sedimentation velocity of S20,W = 110. Electron micrographs of the purified virus showed isometric particles 28 +ACY-plusmn+ADs- 1 nm diameter. Properties of the purified aspen virus and its antiserum showed the virus to be an isolate of tobacco necrosis virus (TNV-A). This is the first report of TNV in aspen. Two additional isolates of TNV antigenically dissimilar to TNV-A and to each other were recovered from one of the same five deteriorating clones. Healthy rooted aspen suckers were infected with purified TNV-A by mechanical inoculation. The possible role of virus infection in aspen deterioration is discussed. Forest Sci. 25:557-567.


2013 ◽  
Vol 21 (1) ◽  
pp. 5-9 ◽  
Author(s):  
Dariusz Sochacki

Abstract The viruses infecting tulips have a big influence on the yield and the quality of bulbs and forced flowers. Commercial bulb production is based on clonal propagation, which leads to the accumulation of viruses. Among 22 viruses occurring in tulips, the most common and the most dangerous are Tulip breaking virus, TBV; Tobacco necrosis virus, TNV; Lily symptomless virus, LSV; Cucumber mosaic virus, CMV and Tobacco rattle virus, TRV. The aim of the research was to check which viruses occur most often on Polish tulip plantations. The research was done on two tulip (Tulipa L.) cultivars ‘Strong Gold’ and ‘Leen van der Mark’ grown at 3 farms situated in different parts of Poland (Warsaw Region, Pomerania and Podlasie) during 2006-2007, and then at 2 farms located in Warsaw Region during 2008-2011. Five of the most important viruses infecting tulips (TBV, TNV, LSV, CMV, and TRV) were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) in leaves and in bulbs during the period 2006-2010. In the last year of the research two different strains of TRV were detected (TRV-J and TRV-F) and Tulip virus X (TVX) as well. Search for viruses showed that most often TBV virus was detected both in the leaves and the bulbs regardless of the year and plantations. Yellow flowering cultivar ‘Strong Gold’ was infected by viruses more often than in bi-coloured (with red) ‘Leen van der Mark’, because of the difficulties with effective roguing of infected plants due to inconspicuous symptoms of virus infections on yellow coloured flowers. Other viruses were detected sporadically, however increasing occurrence of LSV and TRV was noticed from year to year. In 2011, TVX virus was detected in a few plants of ‘Strong Gold’ and it was the first case of detection of this virus in tulip in Poland.


2010 ◽  
Vol 430 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Jens Tilsner ◽  
Karl J. Oparka

Bioimaging contributes significantly to our understanding of plant virus infections. In the present review, we describe technical advances that enable imaging of the infection process at previously unobtainable levels. We highlight how such new advances in subcellular imaging are contributing to a detailed dissection of all stages of the viral infection process. Specifically, we focus on: (i) the increasingly detailed localizations of viral proteins enabled by a diversifying palette of cellular markers; (ii) approaches using fluorescence microscopy for the functional analysis of proteins in vivo; (iii) the imaging of viral RNAs; (iv) methods that bridge the gap between optical and electron microscopy; and (v) methods that are blurring the distinction between imaging and structural biology. We describe the advantages and disadvantages of such techniques and place them in the broader perspective of their utility in analysing plant virus infection.


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