Citrus Leprosis Virus C Encodes Three Proteins With Gene Silencing Suppression Activity

Autor(es)

Leastro, Mikhail Oliveira ^{[1, 2]} ; Ortega Castro, Deibis Yorlenis ^[2] ; Freitas-Astua, Juliana ^{[3, 1]} ; Kitajima, Elliot Watanabe ^[4] ; Pallas, Vicente ^[2] ; Sanchez-Navarro, Jesus Angel ^[2]

Afiliação do(s) autor(es)

^[1] Inst Biol, Unidade Lab Referencia Bio Mol Aplicada, Sao Paulo - Brazil

^[2] Univ Politecn Valencia, Inst Biol Mol & Celular Plantes, Consejo Super Invest Cient CSIC, Valencia - Spain

^[3] Embrapa Mandioca & Fruticultura, Cruz Das Almas - Brazil

^[4] Univ Sao Paulo, Dept Fitopatol & Nematol, Escola Super Agr Luiz de Queiroz, Piracicaba - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN MICROBIOLOGY; v. 11, JUN 9 2020.
• Citações Web of Science: 0

Resumo

Citrus leprosis virus C (CiLV-C) belongs to the genusCilevirus, familyKitaviridae, and is considered the most devastating virus infecting citrus in Brazil, being the main viral pathogen responsible for citrus leprosis (CL), a severe disease that affects citrus orchards in Latin America. Here, proteins encoded by CiLV-C genomic RNA 1 and 2 were screened for potential RNA silencing suppressor (RSS) activity by five methods. Using the GFP-based reporter agroinfiltration assay, we have not found potential local suppressor activity for the five CiLV-C encoded proteins. However, when RSS activity was evaluated using the alfalfa mosaic virus (AMV) system, we found that the p29, p15, and p61 CiLV-C proteins triggered necrosis response and increased the AMV RNA 3 accumulation, suggesting a suppressive functionality. From the analysis of small interfering RNAs (siRNAs) accumulation, we observed that the ectopic expression of the p29, p15, and p61 reduced significantly the accumulation of GFP derived siRNAs. The use of the RSS defective turnip crinkle virus (TCV) system revealed that only thetrans-expression of the p15 protein restored the cell-to-cell viral movement. Finally, the potato virus X (PVX) system revealed that the expression of p29, p15, and p61 increased the PVX RNA accumulation; in addition, the p29 and p15 enhanced the pathogenicity of PVX resulting in the death of tobacco plants. Furthermore, PVX-p61 infection resulted in a hypersensitive response (HR), suggesting that p61 could also activate a plant defense response mechanism. This is the first report describing the RSS activity for CiLV-C proteins and, moreover, for a member of the familyKitaviridae. (AU)

• Processo FAPESP: 15/10249-1 - Estudo dos processos infectivos do vírus da leprose do citros (CiLV-C), com ênfase na construção de clone infeccioso e caracterização das proteínas virais.
• Beneficiário: Mikhail Oliveira Leastro
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/50222-0 - Compreensão sobre a biologia molecular e ecologia da relações planta-vírus-vetor: rumo a estratégias sustentáveis e integradas de manejo de vírus
• Beneficiário: Juliana de Freitas Astúa
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/19898-8 - O envolvimento da proteína de movimento (MP) dos vírus associados com a leprose do citros com a limitação natural do movimento viral sistêmico na planta.
• Beneficiário: Mikhail Oliveira Leastro
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado