title: Understanding superinfection exclusion by complex populations of Citrus tristeza virus.
abstract: Superinfection exclusion (SIE) is a phenomenon in which a primary viral infection restricts a secondary infection with the same or closely related virus. Previously we showed that SIE by Citrus tristeza virus (CTV) occurs only between isolates of the same virus genotype. This work, however, was done using single genotype-containing isolates, while most field citrus trees harbor complex populations composed of different virus genotypes. Here we examined SIE in plants simultaneously infected with several CTV genotypes. The experiments showed that exclusion of a secondary infection by a CTV variant was triggered by the presence of another variant of the same genotype in the primary population, even under the conditions of its low-level accumulation, and was not affected by co-occurrence of additional heterologous genotypes. The same rule appeared to be in effect when SIE by mixed populations was tested in a series of different citrus varieties.
authors.affiliation: University of Florida, Department of Plant Pathology, 2550 Hull Road, Gainesville, FL 32611, USA.
authors.forename: María
authors.initials: M
authors.lastname: Bergua
authors.affiliation: University of Florida, Department of Plant Pathology, 2550 Hull Road, Gainesville, FL 32611, USA.
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Kang
authors.affiliation: University of Florida, Department of Plant Pathology, 2550 Hull Road, Gainesville, FL 32611, USA. Electronic address: svetlana@ufl.edu.
authors.forename: Svetlana Y
authors.initials: SY
authors.lastname: Folimonova
mesh_terms: D002957:Citrus / Q000821:virology*; D017790:Closterovirus / Q000235:genetics / Q000502:physiology*; D005838:Genotype; D010935:Plant Diseases / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D015163:Superinfection / Q000517:prevention & control* / Q000821:virology
chemical_list: D012367:RNA, Viral
keywords: Citrus tristeza virus; Cross-protection; Superinfection exclusion