Viruses (2015) 7, 4945-4959

Jie Zhang, Mingqing Dang, Qingqing Huang and Yajuan Qian (2015)
Determinants of disease phenotype differences caused by closely-related isolates of begomovirus betasatellites inoculated with the same species of helper virus
Viruses 7 (9), 4945-4959
Abstract: Tomato yellow leaf curl China virus (TYLCCNV) is a monopartite begomovirus associated with different betasatellites. In this study, we investigate two different isolates of Tomato yellow leaf curl China betasatellite (TYLCCNB) to determine what features of the viral genome are required for induction of characteristic phenotypic differences between closely-related betasatellite. When co-agroinoculated with TYLCCNV into Nicotiana spp. and tomato plants, TYLCCNB-Y25 induced only leaf curling on all hosts, while TYLCCNB-Y10 also induced enations, vein yellowing, and shoot distortions. Further assays showed that ßC1 of TYLCCNB-Y25 differs from that of TYLCCNB-Y10 in symptom induction and transcriptional modulating. Hybrid satellites were constructed in which the ßC1 gene or 200 nt partial promoter-like fragment upstream of the ßC1 were exchanged. Infectivity assays showed that a TYLCCNB-Y25 hybrid with the intact TYLCCNB-Y10 ßC1 gene was able to induce vein yellowing, shoot distortions, and a reduced size and number of enations. A TYLCCNB-Y10 hybrid with the intact TYLCCNB-Y25 ßC1 gene produced only leaf curling. In contrast, the TYLCCNB-Y25 and TYLCCNB-Y10 hybrids with swapped partial promoter-like regions had little effect on the phenotypes induced by wild-type betasatellites. Further experiments showed that the TYLCCNB-Y25 hybrid carrying the C-terminal region of TYLCCNB-Y10 ßC1 induced TYLCCNB-Y10-like symptoms. These findings indicate that the ßC1 protein is the major symptom determinant and that the C-terminal region of ßC1 plays an important role in symptom induction.
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(original language: English)
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Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tomato yellow leaf curl China virus