PATHOPHYSIOLOGICAL CHANGES IN PEPPER PLANTS INFECTED WITH TOBACCO MOSAIC VIRUS

1997 ◽  
pp. 737-742
Author(s):  
D. Savic ◽  
M. Rakocevic ◽  
L. Stankovic
Plant Disease ◽  
2003 ◽  
Vol 87 (2) ◽  
pp. 202-202 ◽  
Author(s):  
J. F. Murphy ◽  
T. A. Zitter ◽  
A. Erb

Jalapeno pepper plants (Capsicum annuum cv. Jaladuro) grown in Erie County, New York expressed chlorotic oak-leaf patterns along the primary vein of fully expanded leaves. Fruit had patterns of irregular ripening with a bumpy surface. Symptom expression was most obvious in August 2002, when leaf and fruit abscission occurred. Symptomatic fruit samples were tested by western blot analysis for the presence of Cucumber mosaic virus (CMV), Potato virus Y (PVY), Pepper mottle virus (PepMoV), Tobacco etch virus (TEV), and Tobacco mosaic virus (TMV). A positive reaction for TMV, but none of the other viruses, was observed. Symptomatic leaf samples were tested by Agdia, Inc. (Elkhart, IN) for Alfalfa mosaic virus, CMV, Impatiens necrotic spot virus, Pepper mild mottle virus, PepMoV, PVY, TEV, TMV, Tobacco ringspot virus, Tomato ringspot virus, and TSWV and for potyviruses using a group-specific test. The Agdia test confirmed that the pepper plants were infected with TMV. The pepper field where the original samples were collected was surveyed for TMV-infected plants. Fifty symptomatic plants expressing foliar and fruit symptoms similar to those originally tested, and 50 asymptomatic plants were sampled by collection of three leaves per plant and tested using enzyme-linked immunosorbent assay for the presence of TMV. All symptomatic plants and 18% of asymptomatic plants tested positive for TMV. To our knowledge, this is the first occurrence of TMV causing losses in commercially grown pepper in New York.


Author(s):  
Irwin Bendet ◽  
Nabil Rizk

Preliminary results reported last year on the ion etching of tobacco mosaic virus indicated that the diameter of the virus decreased more rapidly at 10KV than at 5KV, perhaps reaching a constant value before disappearing completely.In order to follow the effects of ion etching on TMV more quantitatively we have designed and built a second apparatus (Fig. 1), which incorporates monitoring devices for measuring ion current and vacuum as well as accelerating voltage. In addition, the beam diameter has been increased to approximately 1 cm., so that ten electron microscope grids can be exposed to the beam simultaneously.


Author(s):  
Egbert W. Henry

Tobacco mosaic virus (TMV) infection has been studied in several investigations of Nicotiana tabacum leaf tissue. Earlier studies have suggested that TMV infection does not have precise infective selectivity vs. specific types of tissues. Also, such tissue conditions as vein banding, vein clearing, liquification and suberization may result from causes other than direct TMV infection. At the present time, it is thought that the plasmodesmata, ectodesmata and perhaps the plasmodesmata of the basal septum may represent the actual or more precise sites of TMV infection.TMV infection has been implicated in elevated levels of oxidative metabolism; also, TMV infection may have a major role in host resistance vs. concentration levels of phenolic-type enzymes. Therefore, enzymes such as polyphenol oxidase, peroxidase and phenylalamine ammonia-lyase may show an increase in activity in response to TMV infection. It has been reported that TMV infection may cause a decrease in o-dihydric phenols (chlorogenic acid) in some tissues.


2018 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
André F. Martins ◽  
Zhuo Chen ◽  
Philip M. Palacios ◽  
Chance M. Nowak ◽  
...  

Superoxide overproduction is known to occur in multiple disease states requiring critical care yet non-invasive detection of superoxide in deep tissue remains a challenge. Herein, we report a metal-free magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) active contrast agent prepared by “click conjugating” paramagnetic organic radical contrast agents (ORCAs) to the surface of tobacco mosaic virus (TMV). While ORCAs are known to be reduced <i>in vivo</i> to an MRI/EPR silent state, their oxidation is facilitated specifically by reactive oxygen species—in particular superoxide—and are largely unaffected by peroxides and molecular oxygen. Unfortunately, single molecule ORCAs typically offer weak MRI contrast. In contrast, our data confirm that the macromolecular ORCA-TMV conjugates show marked enhancement for <i>T<sub>1</sub></i> contrast at low field (<3.0 T), and <i>T<sub>2</sub></i> contrast at high field (9.4 T). Additionally, we demonstrated that the unique topology of TMV allows for “quenchless fluorescent” bimodal probe for concurrent fluorescence and MRI/EPR imaging, which was made possible by exploiting the unique inner and outer surface of the TMV nanoparticle. <a>Finally, we show TMV-ORCAs do not respond to normal cellular respiration, minimizing the likelihood for background, yet still respond to enzymatically produced superoxide in complicated biological fluids like serum.</a>


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