scholarly journals The AC2 Protein of a Bipartite Geminivirus Stimulates the Transcription of the BV1 Gene Through Abscisic Acid Responsive Promoter Elements

2020 ◽  
Author(s):  
Rong Sun ◽  
Junping Han ◽  
Limin Zheng ◽  
Feng Qu
Keyword(s):  
Abscisic Acid ◽  
Transcriptional Activation ◽  
Site Directed Mutagenesis ◽  
Bipartite Begomoviruses ◽  
Yellow Mosaic Virus ◽  
Circular Dna ◽  
Late Genes ◽  
Mungbean Yellow Mosaic Virus ◽  
Infected Cells ◽  
And Control

Geminiviruses possess single-stranded, circular DNA genomes, and control the transcription of their late genes, including BV1 of many bipartite begomoviruses, through transcriptional activation by the early expressing AC2 protein. DNA binding by AC2 is not sequence-specific, hence the specificity of AC2 activation is thought to be conferred by plant transcription factors (TFs) recruited by AC2 in infected cells. However, the exact TFs AC2 recruits are not known for most viruses. Here we report a systematic examination of the BV1 promoter (PBV1) of mungbean yellow mosaic virus (MYMV) for conserved promoter motifs. We found that MYMV PBV1 contains three abscisic acid (ABA)-responsive elements (ABREs) within its first 70 nucleotides. Deleting these ABREs, or mutating them all via site-directed mutagenesis, abolished the capacity of PBV1 to respond to AC2-mediated transcriptional activation. Furthermore, ABRE and other related ABA-responsive elements were prevalent in more than a dozen Old World begomoviruses we inspected. Together these findings suggest that ABA-responsive TFs may be recruited by AC2 to BV1 promoters of these viruses to confer specificity to AC2 activation. These observations are expected to guide the search for the actual TF(s), furthering our understanding of the mechanism of AC2 action.

scholarly journals The AC2 Protein of a Bipartite Geminivirus Stimulates the Transcription of the BV1 Gene through Abscisic Acid Responsive Promoter Elements

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1403
Author(s):  
Rong Sun ◽  
Junping Han ◽  
Limin Zheng ◽  
Feng Qu
Keyword(s):  
Abscisic Acid ◽  
Transcriptional Activation ◽  
Site Directed Mutagenesis ◽  
Bipartite Begomoviruses ◽  
Yellow Mosaic Virus ◽  
Circular Dna ◽  
Late Genes ◽  
Mungbean Yellow Mosaic Virus ◽  
Infected Cells ◽  
And Control

Geminiviruses possess single-stranded, circular DNA genomes and control the transcription of their late genes, including BV1 of many bipartite begomoviruses, through transcriptional activation by the early expressing AC2 protein. DNA binding by AC2 is not sequence-specific; hence, the specificity of AC2 activation is thought to be conferred by plant transcription factors (TFs) recruited by AC2 in infected cells. However, the exact TFs AC2 recruits are not known for most viruses. Here, we report a systematic examination of the BV1 promoter (PBV1) of the mungbean yellow mosaic virus (MYMV) for conserved promoter motifs. We found that MYMV PBV1 contains three abscisic acid (ABA)-responsive elements (ABREs) within its first 70 nucleotides. Deleting these ABREs, or mutating them all via site-directed mutagenesis, abolished the capacity of PBV1 to respond to AC2-mediated transcriptional activation. Furthermore, ABRE and other related ABA-responsive elements were prevalent in more than a dozen Old World begomoviruses we inspected. Together, these findings suggest that ABA-responsive TFs may be recruited by AC2 to BV1 promoters of these viruses to confer specificity to AC2 activation. These observations are expected to guide the search for the actual TF(s), furthering our understanding of the mechanisms of AC2 action.

scholarly journals Breeding for Enhancing Legumovirus Resistance in Mungbean: Current Understanding and Future Directions

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 622 ◽  
Author(s):  
Chandra Mohan Singh ◽  
Poornima Singh ◽  
Aditya Pratap ◽  
Rakesh Pandey ◽  
Shalini Purwar ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Seed Quality ◽  
Soil Health ◽  
Mosaic Disease ◽  
Bipartite Begomoviruses ◽  
Yellow Mosaic Virus ◽  
Symbiotic Association ◽  
Detection Techniques ◽  
Vigna Species ◽  
Mungbean Yellow Mosaic Virus

Yellow mosaic disease (YMD) affects several types of leguminous crops, including the Vigna species, which comprises a number of commercially important pulse crops. YMD is characterized by the formation of a bright yellow mosaic pattern on the leaves; in severe forms, this pattern can also be seen on stems and pods. This disease leads to tremendous yield losses, even up to 100%, in addition to deterioration in seed quality. Symptoms of this disease are similar among affected plants; YMD is not limited to mungbean (Vigna radiata L. Wilczek) and also affects other collateral and alternate hosts. In the last decade, rapid advancements in molecular detection techniques have been made, leading to an improved understanding of YMD-causing viruses. Three distinct bipartite begomoviruses, namely, Mungbean Yellow Mosaic India Virus (MYMIV), Mungbean Yellow Mosaic Virus (MYMV), and Horsegram Yellow Mosaic Virus (HgYMV), are known to cause YMD in Vigna spp. Vigna crops serve as an excellent protein source for vegetarians worldwide; moreover, they aid in improving soil health by fixing atmospheric nitrogen through a symbiotic association with Rhizobium bacteria. The loss in the yield of these short-duration crops due to YMD, thus, needs to be checked. This review highlights the discoveries that have been made regarding various aspects of YMD affecting mungbean, including the determination of YMD-causing viruses and strategies used to develop high-yielding YMD-resistant mungbean varieties that harness the potential of related Vigna species through the use of different omics approaches.

Electron Microscopy of a Herpesvirus Isolated from Marek's Disease in Duck and Chicken Embryo Fibroblast Cultures

1968 ◽  
Vol 26 ◽  
pp. 222-223 ◽  
Author(s):  
Keyvan Nazerian
Keyword(s):  
Inclusion Bodies ◽  
Chicken Embryo Fibroblast ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Duck Embryo Fibroblast ◽  
Multinucleated Cells ◽  
Viral Particles ◽  
Infected Cells ◽  
And Control ◽  
Do So

A herpes-like virus has been isolated from duck embryo fibroblast (DEF) cultures inoculated with blood from Marek's disease (MD) infected birds. Cultures which contained this virus produced MD in susceptible chickens while virus negative cultures and control cultures failed to do so. This and other circumstantial evidence including similarities in properties of the virus and the MD agent implicate this virus in the etiology of MD.Histochemical studies demonstrated the presence of DNA-staining intranuclear inclusion bodies in polykarocytes in infected cultures. Distinct nucleo-plasmic aggregates were also seen in sections of similar multinucleated cells examined with the electron microscope. These aggregates are probably the same as the inclusion bodies seen with the light microscope. Naked viral particles were observed in the nucleus of infected cells within or on the edges of the nucleoplasmic aggregates. These particles measured 95-100mμ, in diameter and rarely escaped into the cytoplasm or nuclear vesicles by budding through the nuclear membrane (Fig. 1). The enveloped particles (Fig. 2) formed in this manner measured 150-170mμ in diameter and always had a densely stained nucleoid. The virus in supernatant fluids consisted of naked capsids with 162 hollow, cylindrical capsomeres (Fig. 3). Enveloped particles were not seen in such preparations.

scholarly journals CXCR2 Blockade Influences Anaplasma phagocytophilum Propagation but Not Histopathology in the Mouse Model of Human Granulocytic Anaplasmosis

2004 ◽  
Vol 11 (5) ◽  
pp. 963-968 ◽  
Author(s):  
Diana G. Scorpio ◽  
Mustafa Akkoyunlu ◽  
Erol Fikrig ◽  
J. Stephen Dumler
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Tissue Injury ◽  
Treated Group ◽  
Obligate Intracellular Bacterium ◽  
Human Granulocytic Anaplasmosis ◽  
Obligate Intracellular ◽  
Liver Histopathology ◽  
Granulocytic Anaplasmosis ◽  
Infected Cells ◽  
And Control

ABSTRACT Anaplasma phagocytophilum is an obligate intracellular bacterium that infects neutrophils and causes human granulocytic anaplasmosis. Infection induces neutrophil secretion of interleukin-8 or murine homologs and perpetuates infection by recruiting susceptible neutrophils. We hypothesized that antibody blockade of CXCR2 would decrease A. phagocytophilum tissue load by interrupting neutrophil recruitment but would not influence murine hepatic pathology. C3H-scid mice were treated with CXCR2 antiserum or control prior to or on day 14 after infection. Quantitative PCR and immunohistochemistry for A. phagocytophilum were performed and severity of liver histopathology was ranked. Control mice had more infected cells in tissues than the anti-CXCR2-treated group. The histopathological rank was not different between treated and control animals. Infected cells of control mice clustered in tissue more than in treated mice. The results support the hypothesis of bacterial propagation through chemokine induction and confirm that tissue injury is unrelated to A. phagocytophilum tissue load.

​RCA-based Detection of Begomoviruses in Weed Ggenera Associated with Legumes in Southern Karnataka

2021 ◽  
Author(s):  
Sudeep Pandey ◽  
T.R. Girish ◽  
S. Basavaraj ◽  
A.S. Padmaja ◽  
N. Nagaraju
Keyword(s):  
Mosaic Virus ◽  
Rolling Circle Amplification ◽  
Mosaic Disease ◽  
Yellow Mosaic Virus ◽  
Insect Vector ◽  
Weed Species ◽  
Ageratum Conyzoides ◽  
Yellow Mosaic Disease ◽  
Mungbean Yellow Mosaic Virus ◽  
Legume Crops

Background: Yellow mosaic disease (YMD) caused by begomoviruses transmitted through the insect vector Bemisia tabaci poses a serious threat to the production of legume crops. Methods: Season-long surveys were carried out for YMD occurrence in six different legume crops and associated natural weeds both symptomatic and asymptomatic across the districts of southern Karnataka, India. The samples were analyzed through RCA PCR using specific primer pairs. Result: Up to 94.1 per cent YMD incidence was recorded and nine weed species were commonly found associated with legume crops. The weeds viz., Ageratum conyzoides, Alternanthera sessilis, Commelina benghalensis and Euphorbia geniculata were abundantly found in the surveyed regions. The weeds were both symptomatic and asymptomatic. Rolling circle amplification coupled polymerase chain reaction method was employed to detect yellow mosaic virus in asymptomatic weeds. Phylogenetic analysis based on the sequences of PCR amplified products of weeds and symptomatic legumes revealed a close clustering of the weed samples with horsegram yellow mosaic virus, legume yellow mosaic virus and mungbean yellow mosaic virus. Overall, our data suggests the role of weed species associated with legume crops as alternative/collateral hosts of begomoviruses and their role in the epidemiology of yellow mosaic disease.

Virus Vector Relationship of Yellow Mosaic Virus and Whitefly, Bemisia tabaci (Gennadius) in Soybean

2021 ◽  
Author(s):  
M. Swathi ◽  
Neeta Gaur ◽  
Kamendra Singh
Keyword(s):  
Mosaic Virus ◽  
Virus Disease ◽  
Management Strategies ◽  
Virus Transmission ◽  
Virus Vector ◽  
Yellow Mosaic Virus ◽  
Starvation Period ◽  
Mungbean Yellow Mosaic Virus ◽  
Biological Relationship ◽  
Relationship Of

Background: Whitefly is one of the most destructive sucking pest in the tropical and subtropical regions of the world and causing significant crop losses directly by sucking sap from the plants and indirectly through the transmission of viral diseases specifically caused by the genus Begomovirus. The Begomovirus species viz., Mungbean yellow mosaic India virus (MYMIV) and Mungbean yellow mosaic virus (MYMV) are causing yellow mosaic virus disease in soybean, which is transmitted by whiteflies. The disease accounts to 30-70 per cent yield loss and increases up to 80 - 100 per cent during severe incidence. Hence, there is a need for development of integrated pest management strategies against disease and whiteflies, for this the knowledge on virus-vector relationship is required. But, the studies on biological relationship of yellow mosaic virus disease and whitefly in soybean are scarce. At this juncture, considering the importance of disease in soybean, the present investigation was carried out to know the virus -vector relationship of the YMV and whitefly in soybean.Methods: The experiment on virus-vector relationship of yellow mosaic virus and whitefly in soybean was conducted at Department of Entomology, College of Agriculture, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand during 2016-17. The data on number of whiteflies per plant, acquisition and inoculation access feeding period and pre and post starvation period required for effective transmission of virus was recorded.Result: A single viruliferous whitefly was able to transmit virus and ten viruliferous whiteflies per plant were required for cent per cent transmission of virus. The minimum acquisition access and inoculation access feeding periods required for virus transmission was 0.25h (15 min) each; while the 100 per cent virus transmission was recorded with acquisition and inoculation period of 12h, each. The per cent transmission was increased with the increase of acquisition and inoculation periods. The rate of transmission was positively correlated with pre-acquisition starvation period and negatively correlated with post- acquisition starvation period.

scholarly journals Development of high yielding with durable resistance against Mungbean yellow mosaic virus genotypes in Blackgram

2019 ◽  
pp. 187-193
Author(s):  
Pandiyan M ◽  
Senthil N ◽  
Krishnaveni A ◽  
Sivakumar C ◽  
Singh BB ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Mosaic Virus ◽  
Tamil Nadu ◽  
Durable Resistance ◽  
Yellow Mosaic Virus ◽  
Yield Potential ◽  
Average Height ◽  
Crude Fibre ◽  
Mungbean Yellow Mosaic Virus ◽  
Virus Genotypes

The Blackgram culture VBG04-008 is a cross derivative of blackgram Vamban 3 x Vigna mungo var. silvestris 8 is released as TNAU blackgram VBN (Bg) 7 maturing in 65-70 days with an average height of 17 cm and suited for cultivation under both under rainfed and irrigated conditions. It has a yield potential of 981 Kg per hectare. This culture is resistant to Yellow Mosaic Virus, Powdery mildew and Leaf Curl Virus and less damage of pod borer. It possesses desirable characters like high protein content (21.05%), crude fibre (5.90g/100g) and iron (3.76 mg/100g). Grains are medium sized with black in colour. It is recommended for cultivation in Tamil Nadu, Andhra Pradesh, Karnataka and Orissa. Keywords: VBG04-008; Blackgram; VBN 7 Mung Bean Yellow Mosaic Virus; Powdery mildew-Rainfed; Irrigated

scholarly journals Longevity of wild pansy flowers treated with growth regulators

2018 ◽  
Vol 24 (2) ◽  
pp. 103-108
Author(s):  
Tania Pires Da Silva ◽  
Fernanda Ferreira Araujo ◽  
Fernando Luiz Finger
Keyword(s):  
Weight Loss ◽  
Abscisic Acid ◽  
Growth Regulators ◽  
Water Status ◽  
Fluorescent Light ◽  
Distilled Water ◽  
Fresh Weight ◽  
Exogenous Ethylene ◽  
Fourth Experiment ◽  
And Control

The objective of this study was to evaluate the growth regulators action on the senescence of wild pansy flowers. In the first experiment, floral stems were treated with ethylene for 24 hours at concentrations of 0.1, 1.0, 10, 100 and 1000 μL L-1 and control without the hormone. In a second experiment, the flowers were immersed in solutions of abscisic acid (ABA) containing 5, 20, 50 and 100 μM for one minute and control with water. In a third experiment, 1-methylcyclopropene (1-MCP) was applied at concentrations of 0.5, 1.0 and 1.5 μL L-1 and control without the chemical. In a fourth experiment, 1-MCP and ethylene were applied, where 1-MCP was first applied followed by ethylene. After the treatments with 1-MCP and ethylene, the floral stems were removed from the hermetic chambers and kept in a vessel containing distilled water at 25 °C, 10 μmol m-2 s- 1 white fluorescent light and 50-70% relative humidity as for the ABA treatment. Flowers treated with ethylene did not present significant differences among the concentrations for visual senescence, showing evidence that this flower is not sensitive to ethylene. Treatment with 1000 μL L-1 of ethylene led to a slightly higher fresh weight loss than other treatments, which had a loss of about 33% at end of the experiment. For the ABA treatment, the flowers showed similar fresh weight loss among the different treatments; however, higher concentrations induced slight senescence of flowers. The use of 1-MCP increased the longevity of wild pansy flowers. These results show that 1-MCP is beneficial in maintaining the flower water status, even in the presence of exogenous ethylene, although ethylene may not be directly involved in the senescence of wild pansy flowers.

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