Role Bending: Complex Relationships Between Viruses, Hosts, and Vectors Related to Citrus Leprosis, an Emerging Disease

• Published in: Phytopathology 2015-07, Vol.105 (7), p.1013-1025
• Main Authors: Roy, Avijit, Hartung, John S, Schneider, William L, Shao, Jonathan, Leon, Guillermo, Melzer, Michael J, Beard, Jennifer J, Otero-Colina, Gabriel, Bauchan, Gary R, Ochoa, Ronald, Brlansky, Ronald H
• Format: Article
• Language: English
• Subjects: amino acid sequences; Animals; Arthropod Vectors - virology; Brevipalpus phoenicis; Citrus; Citrus - virology; Citrus leprosis virus C; Colombia; Culicidae; disease vectors; emerging diseases; genes; Host-Pathogen Interactions; hosts; Mexico; mites; Mites - virology; mixed infection; orchards; phylogeny; Plant Diseases; Plant Viruses - physiology; viruses
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/phyto-12-14-0375-fi

Citrus leprosis complex is an emerging disease in the Americas, associated with two unrelated taxa of viruses distributed in South, Central and North America. The cytoplasmic viruses are Citrus leprosis virus C (CiLV-C), Citrus leprosis virus C2 (CiLV-C2) and Hibiscus green spot virus 2 (HGSV-2), whereas the nuclear viruses are Citrus leprosis virus N (CiLV-N) and Citrus necrotic spot virus (CiNSV). These viruses cause local lesion infections in all known hosts, with no natural systemic host identified to date. All leprosis viruses were believed to be transmitted by one species of mite, Brevipalpus phoenicis. However, mites collected from CiLV-C and CiLV-N infected citrus groves in Mexico were identified as B. yothersi and B. californicus sensu lato, respectively, and only B. yothersi was detected from CiLV-C2 and CiLV-N mixed infections in the Orinoco regions of Colombia. Phylogenetic analysis of the helicase, RdRp2 domains and p24 gene amino acid sequences of cytoplasmic leprosis viruses showed a close relationship with recently deposited mosquito-borne Negevirus sequences. Interestingly, we present evidence that both cytoplasmic and nuclear viruses seem to replicate in viruliferous Brevipalpus species. The possible replication in the mite vector and the close relationship with mosquito borne Negevirus are consistent with the concept that members of the genus Cilevirus and Dichorhavirus originated in mites and citrus may play the role of mite virus vector.