Natural Infection of Vicia faba by Bidens mottle virus in Florida

In a study to evaluate the potential of Vicia faba (faba bean) as a cover and forage crop for Florida, 60 accessions of faba bean with diverse genetic backgrounds and geographic origins were acquired from the USDA Germplasm Repository in Pullman, WA. The beans were grown south of Lake Okeechobee in Belle Glade, FL, from December 2000 to April 2001. Reddish-brown elliptical lesions first appeared on the leaflets of two of the faba bean plants 10 to 12 weeks after planting. Within 2 weeks of initial symptoms, a mosaic pattern was expressed on the newly emergent leaves of the same plants. After disease expression, new pods aborted, while developing pods became stunted, distorted, and blistered. Potyvirus cylindrical inclusions (CI) were found in leaf strips (1) of the original plants. Viral symptoms were expressed in manually inoculated plants of Chenopodium amaraticolor, C. quinoa, Lactuca sativa, Nicotiana benthamiana, Petunia × hybrida, Verbena × hybrida, Vicia faba, and Zinnia elegans. Inoculated species of Phaseolus and Pisum were not infected. The virus causing the disease was identified as Bidens mottle virus (2) based on host range, characteristic CI in Z. elegans, and homologous lines of precipitation in SDS-immunodiffusion using antiserum to Bidens mottle and a known antigen. Both the primary host of this virus Bidens mottle virus and its aphid vectors are ubiquitous throughout Florida. To our knowledge, this is the first report of Bidens mottle virus infecting a member of the Leguminosae. References: (1) R. G. Christie and J. R. Edwardson. Light and Electron Microscopy of Plant Virus. Monogr. 9, IFAS, University of Florida, 1994. (2) D. E. Purcifull et al. Bidens mottle virus. Descriptions of Plant Viruses. No. 161. CMI/AAB, Surrey, England, 1976.

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Infectivity of nanovirus DNAs: induction of disease by cloned genome components of Faba bean necrotic yellows virus

Journal of General Virology ◽

10.1099/vir.0.81753-0 ◽

2006 ◽

Vol 87 (6) ◽

pp. 1735-1743 ◽

Cited By ~ 30

Author(s):

T. Timchenko ◽

L. Katul ◽

M. Aronson ◽

J. C. Vega-Arreguín ◽

B. C. Ramirez ◽

...

Keyword(s):

Vicia Faba ◽

Experimental Infection ◽

Faba Bean ◽

Acyrthosiphon Pisum ◽

Dna Delivery ◽

Circumstantial Evidence ◽

Disease Symptoms ◽

Bean Plants ◽

Field Samples ◽

Aphid Vectors

Circumstantial evidence suggests that the genome of Faba bean necrotic yellows virus (FBNYV), a nanovirus, consists of eight distinct, circular, single-stranded DNAs, each of about 1 kb and encoding only one protein. Here, the use of cloned full-length FBNYV DNAs for reproducing FBNYV-like symptoms in Vicia faba, the principal natural host of FBNYV, is reported. Characteristic symptoms of FBNYV infection were obtained in faba bean plants following biolistic DNA delivery or agroinoculation with all eight FBNYV DNAs. Although the eight different DNAs have been invariably detected in field samples infected with the various geographical FBNYV isolates, experimental infection with different combinations of fewer than eight DNAs also led to typical FBNYV symptoms. Even only five genome components, DNA-R, DNA-S, DNA-M, DNA-U1 and DNA-U2, were sufficient for inducing disease symptoms in V. faba upon agroinoculation. Symptomatic plants agroinoculated or bombarded with eight DNAs contained typical FBNYV virions; however, the virus was not transmitted by Aphis craccivora or Acyrthosiphon pisum, two efficient aphid vectors of FBNYV.

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Circulative Nonpropagative Aphid Transmission of Nanoviruses: an Oversimplified View

Journal of Virology ◽

10.1128/jvi.00780-15 ◽

2015 ◽

Vol 89 (19) ◽

pp. 9719-9726 ◽

Cited By ~ 23

Author(s):

Anne Sicard ◽

Jean-Louis Zeddam ◽

Michel Yvon ◽

Yannis Michalakis ◽

Serafin Gutiérrez ◽

...

Keyword(s):

Salivary Glands ◽

Faba Bean ◽

Plant Viruses ◽

The Body ◽

Virus Species ◽

Content Type ◽

Aphid Vector ◽

Arthropod Vectors ◽

The Family ◽

Aphid Vectors

ABSTRACTPlant virus species of the familyNanoviridaehave segmented genomes with the highest known number of segments encapsidated individually. They thus likely represent the most extreme case of the so-called multipartite, or multicomponent, viruses. All species of the family are believed to be transmitted in a circulative nonpropagative manner by aphid vectors, meaning that the virus simply crosses cellular barriers within the aphid body, from the gut to the salivary glands, without replicating or even expressing any of its genes. However, this assumption is largely based on analogy with the transmission of other plant viruses, such as geminiviruses or luteoviruses, and the details of the molecular and cellular interactions between aphids and nanoviruses are poorly investigated. When comparing the relative frequencies of the eight genome segments in populations of the speciesFaba bean necrotic stunt virus(FBNSV) (genusNanovirus) within host plants and within aphid vectors fed on these plants, we unexpectedly found evidence of reproducible changes in the frequencies of some specific segments. We further show that these changes occur within the gut during early stages of the virus cycle in the aphid and not later, when the virus is translocated into the salivary glands. This peculiar observation, which was similarly confirmed in three aphid vector species,Acyrthosiphon pisum,Aphis craccivora, andMyzus persicae, calls for revisiting of the mechanisms of nanovirus transmission. It reveals an unexpected intimate interaction that may not fit the canonical circulative nonpropagative transmission.IMPORTANCEA specific mode of interaction between viruses and arthropod vectors has been extensively described in plant viruses in the three familiesLuteoviridae,Geminiviridae, andNanoviridae, but never in arboviruses of animals. This so-called circulative nonpropagative transmission contrasts with the classical biological transmission of animal arboviruses in that the corresponding viruses are thought to cross the vector cellular barriers, from the gut lumen to the hemolymph and to the salivary glands, without expressing any of their genes and without replicating. By monitoring the genetic composition of viral populations during the life cycle ofFaba bean necrotic stunt virus(FBNSV) (genusNanovirus), we demonstrate reproducible genetic changes during the transit of the virus within the body of the aphid vector. These changes do not fit the view that viruses simply traverse the bodies of their arthropod vectors and suggest more intimate interactions, calling into question the current understanding of circulative nonpropagative transmission.

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