Dissertation
BIOLOGICAL AND MOLECULAR INVESTIGATIONS INTO TOSPOVIRUS-HOST INTERACTIONS
Doctor of Philosophy (PhD), Washington State University
01/2019
Handle:
https://hdl.handle.net/2376/111682
Abstract
Tospoviruses (genus Tospovirus, family Peribunyaviridae) cause significant losses to a wide range of crops worldwide. The continued emergence of new tospoviruses and resistant breaking strains, and their expansion to new regions and hosts underscore the need of new knowledge for a better understanding of the pathogen and the disease.
The tertiary structures of the nucleoprotein (N) and the silencing suppressor protein (NSs) of Tomato spotted wilt virus (TSWV) were determined using a suite of 3D modeling algorithms. The modelers provided an accurate prediction for the N protein, allowing the localization of the conserved residues. For NSs protein models, however, there was no agreement among the three algorithms used.
The response to TSWV infection in tomato cultivars with or without the resistant gene Sw-5 was determined at the small RNA level. The TSWV genome was differentially processed among each of the three viral genomic RNAs in the Sw-5(-) and Sw-5(+) genotypes. In the Sw-5(+) cultivar, the large (L) RNA was the source of the highest number of viral-derived small-interfering RNAs (vsiRNAs), whereas in the Sw-5(-) cultivar, the number was higher in the small (S) RNA. The distribution of hotspots showed a higher number of reads per million reads of vsiRNAs at the 5’ and 3’ ends of the L and S RNAs.
Extracellular ATP (eATP) signaling was also studied on virus infection. TSWV and Turnip mosaic virus (TuMV) were used to inoculate Arabidopsis plants. Results indicated that eATP did reduce the viral infection, which however was not mediated through the function of the canonical ATP receptor in case of both TSWV and TuMV infection, suggesting the presence of an alternative receptor or co-receptor for eATP. The findings provided insights into the potential role of an eATP for defense against TSWV and TuMV.
On a worldwide basis, new and emergent tospoviruses have been increasing in the last decade. In Colombia, samples of tomato and pepper with symptoms suggestive of tospovirus infection were tested. Molecular characterization showed that the samples were infected by Alstroemeria necrotic spot virus (ANSV). This was the first report of natural infection of tomato and pepper by ANSV.
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Details
- Title
- BIOLOGICAL AND MOLECULAR INVESTIGATIONS INTO TOSPOVIRUS-HOST INTERACTIONS
- Creators
- Cristian Andrés Olaya Arias
- Contributors
- Hanu R Pappu (Advisor)Amit Dhingra (Committee Member)Patricia Okubara (Committee Member)Kiwamu Tanaka (Committee Member)Anna Whitfield (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Plant Pathology
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 205
- Identifiers
- 99900581505701842
- Language
- English
- Resource Type
- Dissertation