1,721,041 research outputs found
In vitro behaviour of tobacco germplasm with mixed infections of cucumber mosaic virus and potato virus YN
No full textNew advances on in vitro antiviral chemotherapy
No full textThe detrimental effects of virus infections on yield quantity/quality highlight the importance of virus-free propagation material and underline the need to produce virus-free plant material for the growth industry. Since 1992, this Unit investigates the antiviral activity of several drugs improving eradication of virus diseases as chemotherapy offers wide alternative possibilities.
At the beginning our researches were focused on the use of three well known synthetic nucleotide analogues: ribavirin, DHT and DHPA. Results were obtained in the control of Plum Pox Potyvirus and Prunus Necrotic Ringspot Ilarvirus on a selection of Prunus cerasifera explants.
From these successes, new antiviral groups characterized by different action mechanism were investigated: inosine monophosphate dehydrogenase (IMPDH), S-adenosilhomocysteine hydrolase (SAH) and neuraminidase (NA) inhibitors. The first screening was conducted on the in vitro system Nicotiana tabacum cv Xanthi/Cucumber Mosaic Cucumovirus treated with drugs of these groups obtaining positive results for all combinations (reported on the XIII Meeting SIPaV).
Next trials were applied for the sanitation of grapevines characterized by compromised sanitary condition. Treatments showed a good control on Grapevine Leafroll associated Ampelovirus-3 infection in in vitro Sangiovese explants achiving 100% free explants for NA inhibitors. In vitro Sagrantino plantlets infected by Grapevine Vitivirus A were treated with the same compounds and virus eradication was obtained with the combination of IMPDH and SAH inhibitors
Susceptibility of grapevine viruses to thermotherapy on in vitro collection of Kober 5BB
No full textA number of virus elimination protocols have been developed to obtain healthy plants but their success rates have been variable due to the strong virus-host relationship, treatment performances and experimental condition. An in vitro collection of plants of Vitis berlandieri x Vitis riparia Kober 5BB single-infected by Grapevine vitivirus A (GVA), Grapevine fanleaf nepovirus (GFLV), Grapevine fleck maculavirus (GFkV), Grapevine leafroll ampelovirus 1 (GLRaV-1) and Grapevine leafroll ampelovirus 3 (GLRaV-3) was established to carry out thermotherapy treatments. The experimental system allowed to control the effects of host genotype by using the same genetic background, and the environmental condition such as relative humidity, soil and temperature conditions. Trials were conducted in a growth chamber set at 37 ±0.5 °C for 48 days using in vitro cultures for all infections. ELISA and RT-PCR were used to check sanitary conditions. Results showed complete eradication of GFLV and no effect against GFkV. Different sanitation rates were obtained for other phloematic viruses: 70.2% for GVA, 25.1% for GFLaV-1 and 24.7% for GLRaV-3. The results on phloematic viruses showed a gradient of elimination efficiency which could not be completely explained with the location of viral particles that seems to be only one of the several factors affecting virus susceptibility to heat stress. Moreover, the advantages of this experimental system provide the opportunity to obtain a greater understanding of the thermotherapeutic effects on phloematic viruses
Considerazioni sul possibile ruolo dell'ozono nel determinismo del deperimento dei boschi in Europa
No full text
Differential antiviral activity of some IMPDH inhibitors
No full textChemical procedures, one of the experimental approaches for restoring to health parts of infected plants, have been evaluated for their ability to interfere with virus replication in host tissue. Few chemicals have been found to eliminate or reduce replication of phytoviruses as compared to the broad selections of therapeutic chemicals available against human viruses.
With regard to inhibitors of the inosine monophosphate dehydrogenase (IMPDH) group, two types of compounds endowed with antiviral activity have been discovered: synthetic nucleoside inhibitors, as Tiazofurin (2-β-D-ribofuranosylthiazole-4-carboxamide), Benzamide-Riboside [3-(1-deoxy-β-D-ribofuranosyl)benzamide] and non-nucleoside inhibitors, as Mycophenolic-acid (6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydroisobenzofuran-5-yl)-4-methyl-hex-4-enoic acid).
One of our projects carried out to investigate the antiviral activity of several IMPDH inhibitors was designed to verify their action on an in vitro system (explants of Nicotiana tabacum cv Xanthi infected by Cucumber Mosaic Virus) developed as a rapid technique to identify suitable compounds against plant viruses.
The appropriate drug concentration was evaluated by preliminary screening on healthy explants. ELISA and biological assays were used to identify the sanitary conditions of treated explants after each therapeutic cycle. After healing treatments, ELISA-negative explants were follewed by biological assays on in vivo N. benthamiana plants.
At the end, ELISA readings and biological assays showed 66.6%, 60.0 % and 27.2 % non-infected explants following Mycophenolic-acid, Benzamide-Riboside and Tiazofurin treatment respectively.
We also tested drugs against Tobacco Mosaic Virus infection, but no eradication was achieved by any drugs .
Our results thus represent a starting point for an in-depth analysis of the potential action of IMPDH inhibitors against phytoviruses as well
- …
