The aim of our work was to study the molecular
mechanisms involved in symptoms appearance of plants
inoculated either with a virus or with a virus-satellite
complex.
In the first case, we tried to set up a reliable method for an
early identification of PVYNTN strains present in Italy and
causing potato tuber necrosis. This, to prevent their spread
in the field and to avoid severe yield losses, especially in
seed potato production. We tried to localize the particular
genomic region responsible for tuber necrosis. To this
purpose, we carried out RT-PCR experiments using various
primer combinations, covering PVY genomic regions larger
than those previously used by other authors. As the previous
researchers, though, we were not able to differentiate all
NTN from others PVY strains. This probably because of the
frequent virus variability, due to both genomic mutations
and possible recombination events among different strains.
In the second case, we studied the influence of Y-sat
(CaRNA5 satellite) on symptoms of CMV (Cucumber
mosaic virus) in Nicotiana benthamiana plants: strong
yellowing appearance instead of simple mosaic.
Wang et al (2004), inoculating the same infectious complex
on tobacco plants transformed with a viral suppressor of
plant silencing (HC-PRO), did not experience the
occurrence of yellowing anymore and, therefore,
hypotesized that changes in symptoms were due to plant
post transcriptional gene silencing (PTGS) mechanism. In
our case, inoculation of N. benthamiana plants transformed
with another PTGS viral suppressor (p19), and other plants
defective for RNA polymerase 6 (involved in systemic
silencing), still resulted in yellowing appearance. This, to
our opinion, suggests that in our system another possible
mechanism is involved.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:694 |
| Date | 06 June 2008 |
| Creators | Contaldo, Nicoletta <1978> |
| Contributors | Faccioli, Gianni |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | Italian |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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