Epidemiology of Cauliflower Mosaic virus in South Australia

1967 ◽  
Vol 18 (2) ◽  
pp. 289 ◽  
Author(s):  
JW Randles ◽  
NC Crowley

Results are presented of 3 years of aphid trapping and 3 years of surveys of the incidence of infection with cauliflower mosaic virus in Brassica crops at two sites in South Australia. Mosaic infection has been found to be of importance only in cauliflower plantings. The incidence of the disease varied greatly at the two sites, which were located in climatically different regions. In the Adelaide Hills significant spread of the disease occurred only through the autumn months March, April, and May, and in only one of the three years did the incidence of the disease reach epidemic proportions. On the Adelaide Plains spread of the disease occurred throughout the cooler months of the year, from March till September. At both locations increasing incidence of the disease followed increases in the number of trapped aphid vector species. Results indicate that the most important vector in the field is likely to be Brevicoryne brassicae. Trials suggest that seed-bed infection with the virus can be reduced by the use of barrier crops.

2005 ◽  
Vol 79 (21) ◽  
pp. 13587-13593 ◽  
Author(s):  
Aranzazu Moreno ◽  
Eugénie Hébrard ◽  
Marilyne Uzest ◽  
Stéphane Blanc ◽  
Alberto Fereres

ABSTRACT Viruses frequently use insect vectors to effect rapid spread through host populations. In plant viruses, vector transmission is the major mode of transmission, used by nearly 80% of species described to date. Despite the importance of this phenomenon in epidemiology, the specificity of the virus-vector relationship is poorly understood at both the molecular and the evolutionary level, and very limited data are available on the precise viral protein motifs that control specificity. Here, using the aphid-transmitted Cauliflower mosaic virus (CaMV) as a biological model, we confirm that the “noncirculative” mode of transmission dominant in plant viruses (designated “mechanical vector transmission” in animal viruses) involves extremely specific virus-vector recognition, and we identify an amino acid position in the “helper component” (HC) protein of CaMV involved in such recognition. Site-directed mutagenesis revealed that changing the residue at this position can differentially affect transmission rates obtained with various aphid species, thus modifying the spectrum of vector species for CaMV. Most interestingly, in a virus line transmitted by a single vector species, we observed the rapid appearance of a spontaneous mutant specifically losing its transmissibility by another aphid species. Hence, in addition to the first identification of an HC motif directly involved in specific vector recognition, we demonstrate that change of a virus to a different vector species requires only a single mutation and can occur rapidly and spontaneously.


2021 ◽  
Author(s):  
Quentin Chesnais ◽  
Maxime Verdier ◽  
Myriam Burckbuchler ◽  
Véronique Brault ◽  
Mikhail Pooggin ◽  
...  

2012 ◽  
Vol 93 (3) ◽  
pp. 662-667 ◽  
Author(s):  
Aranzazu Moreno ◽  
W. Freddy Tjallingii ◽  
Gabriela Fernandez-Mata ◽  
Alberto Fereres

Inoculation of the semi-persistent cauliflower mosaic virus (CaMV, genus Caulimovirus) is associated with successive brief (5–10 s) intracellular stylet punctures (pd) when aphids probe in epidermal and mesophyll cells. In contrast to non-persistent viruses, there is no evidence for which of the pd subphases (II-1, II-2 and II-3) is involved in the inoculation of CaMV. Experiments were conducted using the electrical penetration graph (EPG) technique to investigate which particular subphases of the pd are associated with the inoculation of CaMV to turnip by its aphid vector Brevicoryne brassicae. In addition, the same aphid species/test plant combination was used to compare the role of the pd subphases in the inoculation of the non-persistent turnip mosaic virus (TuMV, genus Potyvirus). Inoculation of TuMV was found to be related to subphase II-1, confirming earlier results, but CaMV inoculation appeared to be related exclusively to subphase II-2 instead. The mechanism of CaMV inoculation and the possible nature of subphase II-2 are discussed in the scope of our findings.


Author(s):  
Roberto Alers-Velazquez ◽  
Sushant Khandekar ◽  
Clare Muller ◽  
Jennifer Boldt ◽  
Scott Leisner

AbstractLower temperatures delayed development of systemic symptoms by Cauliflower mosaic virus (CaMV) in two different plant hosts. However, lower temperature exposure increased CaMV nucleic acid levels in leaves of systemically-infected turnips. Furthermore, lower temperature altered the formation of aggregates formed by the CaMV major inclusion body (IB) protein, P6. Finally, lower temperature altered the architecture of the actin cytoskeleton. These data may suggest that lower temperatures alter the actin cytoskeleton, facilitating the formation of larger IBs that hold on to their internal virions more strongly than small ones, impairing virus particle release and causing a delay in systemic infection.


2002 ◽  
Vol 15 (10) ◽  
pp. 1050-1057 ◽  
Author(s):  
Yongzhong Li ◽  
Scott M. Leisner

The Cauliflower mosaic virus (CaMV) gene VI product (P6) is a multifunctional protein essential for viral propagation. It is likely that at least some of these functions require P6 self-association. The work described here was performed to confirm that P6 self-associates and to identify domains involved in this interaction. Yeast two-hybrid analyses indicated that full-length P6 self-associates and that this interaction is specific. Additional analyses indicated that at least four independent domains bind to full-length P6. When a central domain (termed domain D3) was removed, these interactions were abolished. However, this deleted P6 was able to bind to the full-length wild-type protein and to isolated domain D3. Viruses lacking domain D3 were incapable of producing a systemic infection. Isolated domain D3 was capable of binding to at least two of the other domains but was unable to self-associate. This suggests that domain D3 facilitates P6 self-association by binding to the other domains but not itself. The presence of multiple domains involved in P6 self-association may help explain the ability of this protein to form the intracellular inclusions characteristic of caulimoviruses.


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