Field evaluation of dasheen mosaic virus-free cocoyam plants produced by in vitro techniques

1997 ◽  
Vol 68 (1-4) ◽  
pp. 37-47 ◽  
Author(s):  
R. Valverde ◽  
L. Gomez ◽  
F. Saborio ◽  
S. Torres ◽  
O. Arias ◽  
...  
2020 ◽  
Vol 51 (2) ◽  
pp. 665-674
Author(s):  
Nerway & et al.

This study was conducted to investigate the effect of different in vitro techniques on elimination of dahlia mosaic virus. Meristems of Dahlia mosaic virus (DMV) infected dahlias, with 0.2-0.3 mm in length, were cultured on Murashige and Skoog (MS) medium. Based on DAS-ELISA, 100% of the survived plantlets by meristem culture were virus-free. DMV infected stem segments with two axillary buds were treated at three different levels of electric currents (15, 25 and 35 mA) and two time courses (10 and 20 min) in an electrophoresis tank and cultured on MS medium. The treatment of 35 mA for 20 min was the best for viral elimination from diseased dahlias by 85% followed by 25 mA for 20 min by 70%. Acyclovir and salicylic acid were the antivirals were used to eliminate DMV from the infected dahlias. For chemotherapy, nodes were cultured on MS media supplemented with antivirals at 0, 10, 20, 30, 40 and 50 mg/l for 20 and 30 days. The highest concentration of acyclovir (50 mg/l) for 30 days were the best treatments as its highest effectiveness on elimination ability (90.67%) but gave only 49% for plantlet survival. Whereas 40 mg/l acyclovir for 30 days gave elimination ability (80%) and plantlet survival (89.67%). The therapy containing salicylic acid at 40 mg/l for 30 days was the best as its highest effectiveness on DMV elimination ability (100%). But the concentration of salicylic acid at 30 mg/l for 30 days was the best treatment (chemotherapy efficiency= 49.21) as well as DMV elimination ability (75.33%) and plant survival (65.33%). The in vitro developed dahlia plantlets were tested for DMV-freeness using DAS-ELISA. The using therapies (electrotherapy and chemotherapy) can play a good role in virus elimination because they need the minimum period of time to regenerate fully developed healthy plants as long as 2-3 months.


2011 ◽  
Vol 3 (5) ◽  
pp. 491-494
Author(s):  
Dr. Haritha Kumari Nimmagadda ◽  
◽  
Pooja Pant Pooja Pant ◽  
Rajeev Mukhia ◽  
Dr. Aruna Mukherjee

Author(s):  
Jaynthy C. ◽  
N. Premjanu ◽  
Abhinav Srivastava

Cancer is a major disease with millions of patients diagnosed each year with high mortality around the world. Various studies are still going on to study the further mechanisms and pathways of the cancer cell proliferation. Fucosylation is one of the most important oligosaccharide modifications involved in cancer and inflammation. In cancer development increased core fucosylation by FUT8 play an important role in cell proliferation. Down regulation of FUT8 expression may help cure lung cancer. Therefore the computational study based on the down regulation mechanism of FUT8 was mechanised. Sapota fruit extract, containing 4-Ogalloylchlorogenic acid was used as the inhibitor against FUT-8 as target and docking was performed using in-silico tool, Accelrys Discovery Studio. There were several conformations of the docked result, and conformation 1 showed 80% dock score between the ligand and the target. Further the amino acids of the inhibitor involved in docking were studied using another tool, Ligplot. Thus, in-silico analysis based on drug designing parameters shows that the fruit extract can be studied further using in-vitro techniques to know its pharmacokinetics.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 506b-506
Author(s):  
Carol D. Robacker ◽  
S.K. Braman

Azalea lace bug (Stephanitis pyrioides) is the most serious pest on azalea. Results of laboratory bioassays and field evaluations of 17 deciduous azalea taxa have identified three resistant taxa: R. canescens, R. periclymenoides, and R. prunifolium. Highly susceptible taxa are `Buttercup', `My Mary', R. oblongifolium, and the evergreen cultivar `Delaware Valley White'. To determine whether in vitro techniques would have potential value in screening or selecting for resistance, or for the identification of morphological or chemical factors related to resistance, an in-vitro screening assay was developed. In-vitro shoot proliferation was obtained using the medium and procedures of Economou and Read (1984). Shoots used in the bioassays were grown in culture tubes. Two assays were developed: one for nymphs and one for adult lace bugs. To assay for resistance to nymphs, `Delaware Valley White' leaves containing lace bug eggs were disinfested with 70% alcohol and 20% commercial bleach, and incubated in sterile petri plates with moistened filter paper until the nymphs hatched. Five nymphs were placed in each culture tube, and cultures were incubated for about 2 weeks, or until adults were observed. To assay for resistance to adults, five female lace bugs were placed in each culture tube and allowed to feed for 5 days. Data collected on survival and leaf damage was generally supportive of laboratory bioassays and field results. Adult lace bugs had a low rate of survival on resistant taxa. Survival of nymphs was somewhat reduced on resistant taxa.


2019 ◽  
Vol 33 (9) ◽  
pp. 1285-1297 ◽  
Author(s):  
Cornelia Wiegand ◽  
Martin Abel ◽  
Uta-Christina Hipler ◽  
Peter Elsner ◽  
Michael Zieger ◽  
...  

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anthony Gobert ◽  
Yifat Quan ◽  
Mathilde Arrivé ◽  
Florent Waltz ◽  
Nathalie Da Silva ◽  
...  

AbstractPlant viruses cause massive crop yield loss worldwide. Most plant viruses are RNA viruses, many of which contain a functional tRNA-like structure. RNase P has the enzymatic activity to catalyze the 5′ maturation of precursor tRNAs. It is also able to cleave tRNA-like structures. However, RNase P enzymes only accumulate in the nucleus, mitochondria, and chloroplasts rather than cytosol where virus replication takes place. Here, we report a biotechnology strategy based on the re-localization of plant protein-only RNase P to the cytosol (CytoRP) to target plant viruses tRNA-like structures and thus hamper virus replication. We demonstrate the cytosol localization of protein-only RNase P in Arabidopsis protoplasts. In addition, we provide in vitro evidences for CytoRP to cleave turnip yellow mosaic virus and oilseed rape mosaic virus. However, we observe varied in vivo results. The possible reasons have been discussed. Overall, the results provided here show the potential of using CytoRP for combating some plant viral diseases.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 963
Author(s):  
Maria C. Holeva ◽  
Athanasios Sklavounos ◽  
Rajendran Rajeswaran ◽  
Mikhail M. Pooggin ◽  
Andreas E. Voloudakis

Cucumber mosaic virus (CMV) is a destructive plant virus with worldwide distribution and the broadest host range of any known plant virus, as well as a model plant virus for understanding plant–virus interactions. Since the discovery of RNA interference (RNAi) as a major antiviral defense, RNAi-based technologies have been developed for plant protection against viral diseases. In plants and animals, a key trigger of RNAi is double-stranded RNA (dsRNA) processed by Dicer and Dicer-like (DCL) family proteins in small interfering RNAs (siRNAs). In the present study, dsRNAs for coat protein (CP) and 2b genes of CMV were produced in vitro and in vivo and applied onto tobacco plants representing a systemic solanaceous host as well as on a local host plant Chenopodium quinoa. Both dsRNA treatments protected plants from local and systemic infection with CMV, but not against infection with unrelated viruses, confirming sequence specificity of antiviral RNAi. Antiviral RNAi was effective when dsRNAs were applied simultaneously with or four days prior to CMV inoculation, but not four days post inoculation. In vivo-produced dsRNAs were more effective than the in vitro-produced; in treatments with in vivo dsRNAs, dsRNA-CP was more effective than dsRNA-2b, while the effects were opposite with in vitro dsRNAs. Illumina sequencing of small RNAs from in vivo dsRNA-CP treated and non-treated tobacco plants revealed that interference with CMV infection in systemic leaves coincides with strongly reduced accumulation of virus-derived 21- and 22-nucleotide (nt) siRNAs, likely generated by tobacco DCL4 and DCL2, respectively. While the 21-nt class of viral siRNAs was predominant in non-treated plants, 21-nt and 22-nt classes accumulated at almost equal (but low) levels in dsRNA treated plants, suggesting that dsRNA treatment may boost DCL2 activity. Taken together, our findings confirm the efficacy of topical application of dsRNA for plant protection against viruses and shed more light on the mechanism of antiviral RNAi.


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