Progress 10/01/08 to 09/30/13
Outputs
Target Audience: Target audiences were plant virologists, plant pathologists, plant breeders, and graduate students. Changes/Problems: Because fungal viruses were not found in local isolates of Rhizoctonia solani and other plant pathogenic fungi from rice and soybeans, the project focused only on plant dsRNA viruses. What opportunities for training and professional development has the project provided? The project principal investigator trained a graduate student on methodologies to study dsRNA viruses. How have the results been disseminated to communities of interest? The research results were disseminated to the scientific community through journal articles and oral and poster presentation at conferences. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The biological and molecular characterization of a dsRNA virus from Malabar spinach was accomplished by the PI and collaborators. A novel dsRNA virus was discovered infecting many lima bean cultivars commonly grown in the United States. PCR-based detection protocols for these dsRNA viruses were developed. Furthermore, biological studies on the effect of dsRNA viruses on common bean were conducted by the PI and a graduate student. The complete nucleotide sequences of two viruses from common bean and one from Malabar spinach were published and sequences deposited in the Genbank (National Center for Biotechnology Information). All the research results obtained during the reporting period were delivered by the PI, graduate student, and collaborators in the form of posters and oral presentations at national and international conferences and were published in refereed and non-refereed journals, abstracts, and conference proceedings. The proposed name for a new virus (Bell pepper endornavirus) that was previously characterized by the PI and collaborators was approved by the International Committee for the Taxonomy of Viruses (ICTV) as new taxon of the family Endornaviridae (Adams et al., 2013, Arch Virol 158:2023–2030). The virus family endornaviridae contains species that infect many economically important crops. Two viruses infecting common bean and characterized by the PI and collaborators were proposed to the ICTV as new members of the family endornaviridae. The above reports of new plant viral species have increased the number of endornavirus species and strengthen the taxonomic status of this family. Although some progress on the interaction of these viruses with the host was made, the role of these viruses in the plant remains to be elucidated. Attempts to isolate dsRNA viruses from local isolates of plant pathogenic fungi failed. a. To clone, sequence, and conduct phylogenetic analyses of dsRNA viruses frompepper, tomato, and rice. Because the cloning, sequencing, and phylogenetic analyses of dsRNA viruses of pepper, tomato, and rice have been completed during the previous years of this project, dsRNA viruses from lima bean and Malabar spinach were selected to further fulfill this objective. The cloned and sequenced virus from Malabar spinach is being proposed as a new member of the family Endornaviridae and is closely related to rice endornaviruses. The partially cloned lima bean endornavirus is related to Bell pepper endornavirus. None of these viruses caused visible symptoms. The role of these viruses discovered in apparently healthy plants is not known. b. To screen isolates of Rhizoctonia solani and other plant pathogenic fungi for dsRNA viruses by electrophoretic analysis and clone and sequence the genome of selected viral isolates. Screening local isolates of Rhizoctonia solani from rice and soybeans for dsRNA viruses did not yield viruses. Because of this failure, the project focused only on plant dsRNA viruses. c. To conduct preliminary studies on the host effect of dsRNA viruses. Preliminary studies were conducted with two dsRNA viruses (endornaviruses) of common bean. Two lines of Black Turtle Soup common bean (BTS) were used in comparative studies. One line was infected with both Phaseolus vulgaris endornavirus 1 (PvEV-1) and Phaseolus vulgaris endornavirus 2 (PvEV-2) and the other line was virus-free. The two lines exhibited similar phenotypes. Seeds of the virus-infected line germinated faster and the plants matured earlier when compared with those of the virus-free line. Furthermore, grain yield of the endornavirus-infected line was higher than the grain yield of the endornavirus-free line. When inoculated with tobacco ringspot virus (TRSV), the endornavirus-free BTS line reacted with necrotic local lesions but not systemic infection, whereas the endornavirus-infected BTS line reacted with chlorotic lesions, stunting, systemic necrosis, and in some cases, plant death. Other viruses tested (Bean common mosaic virus and Cucumber mosaic virus) caused similar symptoms in both BTS lines. These results suggest that in BTS, co-infection of endornaviruses with TRSV may overcome the host resistance to systemic infection by TRSV. It is expected that these viruses may cause other effects on the plant host.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Okada, R., Kiyota, E., Moriyama, H., Toshiyuki, F., and Valverde, R. A. 2013. A new endornavirus species infecting Malabar spinach (Basella alba L.). Archives of Virology Published online: 12 October 2013. 10.1007/s00705-013-1875-4.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Okada, R., Young, C. K., Valverde, R. A., Sabanadzovic, S., Aoki, N., Hotate, S., Kiyota, E., Moriyama,H., and Fukuhara, T. 2013. Molecular characterization of two evolutionally distinct endornaviruses co-infecting common bean (Phaseolus vulgaris). Journal of General Virology 93:220-229.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Valverde, R. A., Pastor-Corrales, M. A., Khankhum, S., Osorno, J., and S. Sabanadzovic, S. 2013. Endornaviruses recurrently detected on Mesoamerican but not in Andean bean cultivars. Ann. Rep. Bean Improv. Coop. 56: 57-58.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Khankhum, S. and Valverde, R. A. 2013. Association of endornaviruses of Black Turtle Soup common bean with seed germination, grain yield, and host reaction to Tobacco ringspot virus. Phytopathology 103:S2. 73.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Valverde, R. A. and Navas-Castillo, J. 2013. Are persistent plant viruses novel endophytes? Pages 4-9 in Proc. 5th International Symposium on Plant Protection and Plant Health in Europe May 26-29, Berlin, Germany.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Ghanem-Sabanadzovic, N. G., Khankhum, S., Valverde, R. A., and Sabanadzovic. S. 2013. A novel endornavirus infecting lima bean (Phaseolus lunatus) and its occurrence in lima bean genotypes. Phytopathology 103:S2. 2.
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Research progress on dsRNA viruses has been delivered in oral and poster presentations at the national (the 2012 Annual Meeting of the American Phytopathological) and international (the 2012 Spanish National Congress of Virology) meetings. Completed research has been published in refereed journals. The implications of these and previous discoveries of dsRNA viruses on plant virus taxonomy are being discussed on-line in the Web site of the International Committee on Taxonomy of Viruses. Surveys of viruses from various crops have prompted the discovery of new viral species infecting common bean and avocado. PARTICIPANTS: R.A. Valverde (PI), LSU AgCenter; Sead Sabanadzovic, Mississippi State University; Marcial Pastor-Corrales, USDA/ARS, Beltsville, MD; scientists from Tokyo University of Agriculture and Technology, Japan; and Consejo Superior de Investigaciones Cientificas, Spain. TARGET AUDIENCES: Target audiences include plant virologists, plant breeders and graduate students. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Three new dsRNA viruses infecting common bean and avocado have been completely sequenced and will be proposed to the International Committee on Taxonomy of Viruses as new members of the family Endornaviridae. PCR methods for the detection of these viruses have been developed, tested, and validated. Virus-infected and virus-free lines of common bean cultivars have been identified and seed increased. These lines will be used in comparative experiments to determine the effect of these viruses in the host plant. These accomplishments increase our knowledge on persistent viruses and are the product of effective collaborations among researchers from Japan, Spain, and the United States.
Publications
- Sabanadzovic, S. and Valverde, R. A. 2012 Molecular characterization of an isolate of Japanese holly fern mottle virus from leatherleaf fern. Phytopathology 102:S4.104.
- Valverde, R. A., Okada, R.,Sabanadzovic, S., Pastor-Corrales, M., Fukuhara, T., and Moriyama, H. 2012. Endornaviruses in common bean (Phaseolus vulgaris) germplasm. Phytopathology 102:S4.126.
- Villanueva, F., Sabanadzovic, S., Valverde, R. A., and Navas-Castillo, J. 2012. Complete genome sequence of a double-stranded RNA virus from avocado. Journal of Virology 86:1282-1283.
- Villanueva, F., Sabanadzovic, S., Valverde, R. A., and Navas-Castillo, J. 2012. DsRNA viruses of the families Endornaviridae and Chrysoviridae infecting avocado. Page 89 in Proceedings, XVI Congress of the Spanish Society of Phytopathology. September, 17-21, Malaga, Spain.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: The molecular characterization and the identification of three new species of dsRNA viruses, Bell pepper endornavirus (BPEV), Pepper cryptic virus 1 (PCV-1) and Pepper cryptic virus 2 (PCV-2), infecting pepper were reported. This information, together with their occurrence in pepper genotypes was published in two peer reviewed journals. Based on sequence data and phylogenetic analyses, discussions on the origin of various viral genes, the taxonomy, and the evolution of endornaviruses was presented at an international conference and published in a refereed publication. PCR primers for detection of the three pepper dsRNA viruses were developed, and the detection method validated using seed and foliar tissues. Forty-seven pepper genotypes from the United States and Japan were reported to be infected with BPEV. Seven pepper genotypes were reported to be infected with PCV- 1 and PCV-2 in single or mixed infection. The molecular characterization of dsRNA endornaviruses from melon and avocado was presented in posters at the annual meeting of the American Phytopathological Society and the Spanish National Congress of Virology, respectively. PARTICIPANTS: This research is being conducted with informal collaborations with a team of national and international scientists and students working on dsRNA viruses. R. A. Valverde (PI), LSU AgCenter; S. Sabanadzovic, Mississippi State University; Scientists from Tokyo University of Agriculture and Technology in Japan and Consejo Superior de Investigaciones Cientificas of Spain, USDA/ARS, Salinas, CA, and the Noble Foundation, Ardmore, OK. TARGET AUDIENCES: Plant pathologists, plant virologists, plant breeders, research development personnel of seed companies, and graduate students. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The unique nucleotide sequence of three new dsRNA viruses from pepper was obtained and analyzed. Phylogenetic and sequence analyses performed demonstrated a close relationship with fungal dsRNA viruses. This information supported a proposal for the information to be described as a newly plant virus species. PCR detection of these viruses from seed and foliar tissues was successfully accomplished. Distinct endornavirus species were detected in avocado and melon cultivars in the United States and Spain. Research on molecular and biological characterization is underway. Data on molecular and biological properties will be useful in elucidating their role in plants and will clarify their taxonomic status.
Publications
- Lai, Y., Yi, G., Chen, C., Bhardwaj, K., Tragesser, B. J., Valverde, R. A., Zlotnick, A., Mukhopadhyay, S., Ranjith-Kumar, C. T., and Kao, C. C. 2011. Viral Double-strand RNA-binding Proteins Can Enhance Innate Immune Signaling by Toll-Like Receptor 3. PLoS ONE 6 (10): e25837. doi:10.1371/journal.pone.0025837.
- Okada, R., Kiyota, E., Sabanadzovic, S., Moriyama,H., Fukuhara, T., Saha, P., Roossinck. M. J., Severin, A., and Valverde, R. A. 2011. Bell pepper endornavirus: molecular and biological properties and occurrence in the genus Capsicum. Journal of General Virology 92:2664-2673.
- Roossinck, M. J., Sabanadzovic, S., Ryo Okada, R., and Valverde, R. A. 2011. The remarkable evolutionary history of endornaviruses. Journal of General Virology 92:2674-2678.
- Sabanadzovic, S. and Valverde, R. A. 2011. Properties of two cryptoviruses from pepper (Capsicum annuum). Virus Genes 43:307-312.
- Sabanadzovic, Valverde, R. A., and Wintermantel , W. M. 2011. Molecular characterization of an endornavirus from Cucumis spp. Phytopathology 101: S158.
- Valverde, R. A., Sabanadzovic, S., Okada, R., Navas-Castillo, J., and Fukuhara, T. 2010. Cryptic viruses of Capsicum. In: Proceedings 4th Conference of the International Group on Legume and Vegetable Viruses, May 17-20, 2010, page 40, Antequera, Spain.
- Villanueva, F., Sabanadzovic, S., Valverde, R. A., and Navas-Castillo, J. 2011. Evidencia de infeccion por virus con genoma dsRNA pertenecientes a varios generos en aguacate. In: Proceedings XI Congreso Nacional de Virologia, 29 de Mayo a 1 de Junio, Granada, Espana.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: A database of dsRNA viruses infecting cucurbit genotypes was generated and a previously started database on dsRNA viruses of capsicum expanded. Preliminary reports of the outputs described above were disseminated in oral and poster presentations at professional meetings and during informal meetings with collaborators. Two papers, one on the inheritance of a dsRNA virus in rice and another one on the molecular characterization of a dsRNA virus from Rhododendron were published in refereed journals. PARTICIPANTS: This project is being conducted through informal collaborations with scientists and students working on dsRNA viruses. The main collaborator is Dr. Sead Sabanadzovic, from the department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University. Other collaborators include Dr. Toshiyuki Fukuhara from Tokyo University of Agriculture and Technology in Japan and Dr. Jesus Navas-Castillo of the Consejo Superior de Investigaciones Cientificas of Spain. TARGET AUDIENCES: Target audiences include plant virologists, plant breeders and graduate students. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The complete sequence and molecular characterization of Bell pepper endornavirus (BPEV) was obtained. Analysis of the sequence indicated that this virus has distinct features including a possible new functional domain. There was extensive nucleotide sequence diversity among various isolates of BPEV from different Capsicum species. No detectable interactions between BPEV and four ssRNA viruses in bell pepper were found. The complete sequence and molecular characterization of two partitiviruses infecting pepper and a dsRNA virus from rhododendron were obtained. Using dsRNA as reagent, a new strain of Japanese holly fern mottle virus was identified infecting leatherleaf fern and a RT-PCR detection method developed. This information will help to better detect and understand the role of these viruses in plants.
Publications
- Sabanadzovic, S., Ghanem-Sabanadzovic, A., and Valverde, R. A. 2010. Novel monopartite dsRNA virus from rhododendron. Archives of Virology. Online DOI: 10.1007/s00705-010-0770-5.
- Valverde, R. A., Sabanadzovic, S., and Rush, M. C. 2010. Identification of Oryza sativa endornavirus in rice genotypes from breeding programmes in the United States. Plant Breeding. Online DOI: 10.1111/j.1439-0523.2010.01778.x
- Valverde, R. A., Roossinck, M. J., Sabanadzovic, S., and Navas-Castillo, J. 2010. Biological and molecular properties of an endornavirus infecting bell pepper (Capsicum annuum) Page 70 in Proc. 2nd meeting of the Spanish network of plant virology. Puerto de Santa Maria, Cadiz, Spain.
- Sabanadzovic, S. and Valverde, R. A. 2010. Genomic sequences and simultaneous detection of two cryptic viruses from pepper. Phytopathology 100:S112.
- Okada, R., Kiyota, E., Yong, C. K., Moriyama, H., Fukuhara, T., Sabanadzovic, S., and Valverde, R. 2010. Common molecular properties among plant endornaviruses. Page 266 in Proc. Annual Meeting of the American Association for Virology. Boseman, MT.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: The isolation, cloning, and sequence analyses of viral dsRNAs obtained from rice, pepper, tomato and various plant species were conducted. Generated data were used to obtain and analyze the complete nucleotide sequence of two dsRNA viruses and one ssRNA virus. Furthermore, experiments were performed to develop a practical method to detect endornaviruses. Preliminary studies on the interactions between endornaviruses and conventional plant viruses were initiated in Spain. This is being conducted during sabbatical leave in collaboration with Spanish investigators. Many rice and capsicum genotypes were screened for the presence of dsRNA viruses which generated a database of virus-infected and virus-free cultivars. The above information was disseminated in refereed publications, oral and poster presentations at professional meetings, and during informal meetings with collaborators from other institutions (Mississippi State University, The Noble Foundation, and the Consejo de Investigacioness Cientificas of Spain). PARTICIPANTS: This project is being conducted with informal collaborations with scientists working on similar viruses. Collaborators include Drs. Sead Sabanadzovic, Marilyn Roossinck, and Jesus Navas-Castillo of Mississippi State University, The Noble Foundation, and the Consejo de Investigaciones Cientificas of Spain respectively. TARGET AUDIENCES: Target audiences include plant virologists, plant breeders and graduate students. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Data obtained from dsRNA sequence analyses support the proposition of two new species of dsRNA viruses. Furthermore, using data from initial experiments with viral dsRNA, together with biological and molecular studies, a new species of a ssRNA virus infecting ferns in the United States and causing a severe disease has been reported. A new RT-PCR-based method for the detection of members of the plant endornavirus genus was developed. This was possible with partial sequence data obtained from endornaviruses infecting various plant species. The validation of this method was conducted with success using plant tissues infected with these viruses. This method will be of practical use to detect the presence of endornaviruses in plants. The occurrence and origin of a rice endornavirus, previously reported only in Japan, was determined based on the screening of rice cultivars and analyses of the pedigrees.
Publications
- Valverde, R. A. and Sabanadzovic, S. 2009. A new plant virus with unique properties infecting Japanese holly fern. Journal of General Virology 90:2542-2549.
- Sabanadzovic, S., Valverde, R. A., Brown, J. K., Martin, R. R., and Tzanetakis, I. E. 2009. Southern tomato virus: the link between the families Totiviridae and Partitiviridae. Virus Research 140:130-137.
- Sabanadzovic, S. and Valverde, R. A. 2009. A detection method for endornaviruses from various plant species. Phytopathology 99:S113.
- Valverde, R., Saha, P., Gutierrez, D., Ranjith-Kumar, C., Roossinck, M., and Kao,C. 2009. Bell pepper endornavirus: Host range, sequence and effect on cellular signaling. Phytopathology 99:S134.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Research dealing with the molecular characterization of dsRNA viruses from pepper and rice was started. A dsRNA virus from pepper was partially characterized. Some results were published in a referred journal. PARTICIPANTS: R. A. Valverde, PI and S. Sabanadzovic (Mississippi State University) are closely collaborating on this project. A graduate student, D. Gutierrez conducted some experiments. TARGET AUDIENCES: The target audience for this project are other researchers and graduate students. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Partial sequence for endornaviruses and partitiviruses from rice and pepper and tomato were obtained. This information will be useful to better understand the origin and nature of these plant viruses.
Publications
- Valverde, R. A. and Gutierrez, D. L. 2008. Molecular and biological properties of a putative partitivirus from Jalapeno pepper (Capsicum annuum L.). Revista Mexicana de Fitopatologia 26: 1-6.
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