title: A recombinant begomovirus resulting from exchange of the C4 gene.
abstract: A begomovirus isolated from Malvastrum coromandelianum and tomato originating from Yunnan province (China) was shown to be representative of a new begomovirus species, for which the name tomato leaf curl Yunnan virus (TLCYnV) is proposed. TLCYnV has high levels of sequence identity to tomato yellow leaf curl China virus (TYLCCNV) across the whole genome, except for sequences encompassing the C4 gene. Agrobacterium-mediated inoculation showed TLCYnV to be highly infectious to a range of plant species but poorly infectious to M. coromandelianum. In contrast to TYLCCNV, TLCYnV was shown to infect tomato in the absence of a betasatellite. In field-collected samples, TLCYnV was identified most frequently in tomato in which it was not associated with a betasatellite. Transgenic expression in Nicotiana benthamiana showed that the C4 protein of TYLCCNV did not induce developmental abnormalities, whereas the C4 of TLCYnV induced severe developmental abnormalities, reminiscent of virus symptoms. The genome of TLCYnV was shown to be significantly less methylated in plants than that of TYLCCNV and the C4 protein of TLCYnV was shown to suppress post-transcriptional gene silencing and transcriptional gene silencing more effectively than the C4 of TYLCCNV. The results indicate that TLCYnV evolved from TYLCCNV by recombination, acquiring a more virulent C4, allowing it to dispense with the requirement for a betasatellite. The implications of these findings in relation to the evolution of monopartite begomoviruses are discussed.
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Liling
authors.initials: L
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Jiao
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Tong
authors.initials: T
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Huanran
authors.initials: H
authors.lastname: Gong
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Bi
authors.initials: B
authors.lastname: Wang
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Jhang Road, P.O. Box 577, Faisalabad, Pakistan.
authors.forename: Rob W
authors.initials: RW
authors.lastname: Briddon
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Xueping
authors.initials: X
authors.lastname: Zhou
mesh_terms: D053839:Begomovirus / Q000235:genetics* / Q000302:isolation & purification; D002681:China; D016000:Cluster Analysis; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D018551:Solanum lycopersicum / Q000821:virology; D019660:Malvaceae / Q000821:virology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D014026:Nicotiana / Q000821:virology; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins